Noah Diffenbaugh

All Publications

• TC-GEN: Data-Driven Tropical Cyclone Downscaling Using Machine Learning-Based High-Resolution Weather Model JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS Jing, R., Gao, J., Cai, Y., Xi, D., Zhang, Y., Fu, Y., Emanuel, K., Diffenbaugh, N. S., Bendavid, E. 2024; 16 (10)

  View details for DOI 10.1029/2023MS004203

  View details for Web of Science ID 001326244700001

• Machine learning-based extreme event attribution. Science advances Trok, J. T., Barnes, E. A., Davenport, F. V., Diffenbaugh, N. S. 2024; 10 (34): eadl3242

  Abstract

  The observed increase in extreme weather has prompted recent methodological advances in extreme event attribution. We propose a machine learning-based approach that uses convolutional neural networks to create dynamically consistent counterfactual versions of historical extreme events under different levels of global mean temperature (GMT). We apply this technique to one recent extreme heat event (southcentral North America 2023) and several historical events that have been previously analyzed using established attribution methods. We estimate that temperatures during the southcentral North America event were 1.18° to 1.42°C warmer because of global warming and that similar events will occur 0.14 to 0.60 times per year at 2.0°C above preindustrial levels of GMT. Additionally, we find that the learned relationships between daily temperature and GMT are influenced by the seasonality of the forced temperature response and the daily meteorological conditions. Our results broadly agree with other attribution techniques, suggesting that machine learning can be used to perform rapid, low-cost attribution of extreme events.

  View details for DOI 10.1126/sciadv.adl3242

  View details for PubMedID 39167638

• Tree species explain only half of explained spatial variability in plant water sensitivity. Global change biology Konings, A. G., Rao, K., McCormick, E. L., Trugman, A. T., Williams, A. P., Diffenbaugh, N. S., Yebra, M., Zhao, M. 2024; 30 (7): e17425

  Abstract

  Spatiotemporal patterns of plant water uptake, loss, and storage exert a first-order control on photosynthesis and evapotranspiration. Many studies of plant responses to water stress have focused on differences between species because of their different stomatal closure, xylem conductance, and root traits. However, several other ecohydrological factors are also relevant, including soil hydraulics, topographically driven redistribution of water, plant adaptation to local climatic variations, and changes in vegetation density. Here, we seek to understand the relative importance of the dominant species for regional-scale variations in woody plant responses to water stress. We map plant water sensitivity (PWS) based on the response of remotely sensed live fuel moisture content to variations in hydrometeorology using an auto-regressive model. Live fuel moisture content dynamics are informative of PWS because they directly reflect vegetation water content and therefore patterns of plant water uptake and evapotranspiration. The PWS is studied using 21,455 wooded locations containing U.S. Forest Service Forest Inventory and Analysis plots across the western United States, where species cover is known and where a single species is locally dominant. Using a species-specific mean PWS value explains 23% of observed PWS variability. By contrast, a random forest driven by mean vegetation density, mean climate, soil properties, and topographic descriptors explains 43% of observed PWS variability. Thus, the dominant species explains only 53% (23% compared to 43%) of explainable variations in PWS. Mean climate and mean NDVI also exert significant influence on PWS. Our results suggest that studies of differences between species should explicitly consider the environments (climate, soil, topography) in which observations for each species are made, and whether those environments are representative of the entire species range.

  View details for DOI 10.1111/gcb.17425

  View details for PubMedID 39005206

• The Effect of Flood Exposure on Insurance Adoption Among US Households EARTHS FUTURE Choi, J., Diffenbaugh, N. S., Burke, M. 2024; 12 (7)

  View details for DOI 10.1029/2023EF004110

  View details for Web of Science ID 001257542600001

• Subnational biodiversity reporting metrics for mountain ecosystems NATURE SUSTAINABILITY Ly, A., Geschke, J., Snethlage, M. A., Stauffer, K. L., Nussbaumer, J., Schweizer, D., Diffenbaugh, N. S., Fischer, M., Urbach, D. 2023

  View details for DOI 10.1038/s41893-023-01232-3

  View details for Web of Science ID 001084160500001

• More Frequent and Persistent Heatwaves Due To Increased Temperature Skewness Projected by a High-Resolution Earth System Model GEOPHYSICAL RESEARCH LETTERS Gao, Y., Wu, Y., Guo, X., Kou, W., Zhang, S., Leung, L., Chen, X., Lu, J., Diffenbaugh, N. S., Horton, D. E., Yao, X., Gao, H., Wu, L. 2023; 50 (18)

  View details for DOI 10.1029/2023GL105840

  View details for Web of Science ID 001067399800001

• The influence of natural variability on extreme monsoons in Pakistan NPJ CLIMATE AND ATMOSPHERIC SCIENCE Ashfaq, M., Johnson, N., Kucharski, F., Diffenbaugh, N. S., Abid, M., Horan, M. F., Singh, D., Mahajan, S., Ghosh, S., Ganguly, A. R., Evans, K. J., Islam, S. 2023; 6 (1)

  View details for DOI 10.1038/s41612-023-00462-8

  View details for Web of Science ID 001069699900001

• Drought impacts on the electricity system, emissions, and air quality in the western United States. Proceedings of the National Academy of Sciences of the United States of America Qiu, M., Ratledge, N., Azevedo, I. M., Diffenbaugh, N. S., Burke, M. 2023; 120 (28): e2300395120

  Abstract

  The western United States has experienced severe drought in recent decades, and climate models project increased drought risk in the future. This increased drying could have important implications for the region's interconnected, hydropower-dependent electricity systems. Using power-plant level generation and emissions data from 2001 to 2021, we quantify the impacts of drought on the operation of fossil fuel plants and the associated impacts on greenhouse gas (GHG) emissions, air quality, and human health. We find that under extreme drought, electricity generation from individual fossil fuel plants can increase up to 65% relative to average conditions, mainly due to the need to substitute for reduced hydropower. Over 54% of this drought-induced generation is transboundary, with drought in one electricity region leading to net imports of electricity and thus increased pollutant emissions from power plants in other regions. These drought-induced emission increases have detectable impacts on local air quality, as measured by proximate pollution monitors. We estimate that the monetized costs of excess mortality and GHG emissions from drought-induced fossil generation are 1.2 to 2.5x the reported direct economic costs from lost hydro production and increased demand. Combining climate model estimates of future drying with stylized energy-transition scenarios suggests that these drought-induced impacts are likely to remain large even under aggressive renewables expansion, suggesting that more ambitious and targeted measures are needed to mitigate the emissions and health burden from the electricity sector during drought.

  View details for DOI 10.1073/pnas.2300395120

  View details for PubMedID 37410866

• Using Machine Learning With Partial Dependence Analysis to Investigate Coupling Between Soil Moisture and Near-Surface Temperature JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Trok, J. T., Davenport, F. V., Barnes, E. A., Diffenbaugh, N. S. 2023; 128 (12)

  View details for DOI 10.1029/2022JD038365

  View details for Web of Science ID 001022733800001

• Exploring the Influence of Summer Temperature on Human Mobility During the COVID-19 Pandemic in the San Francisco Bay Area. GeoHealth Ly, A., Davenport, F. V., Diffenbaugh, N. S. 2023; 7 (6): e2022GH000772

  Abstract

  Studies on the relationship between temperature and local, small scale mobility are limited, and sensitive to the region and time period of interest. We contribute to the growing mobility literature through a detailed characterization of the observed temperature-mobility relationship in the San Francisco Bay Area at fine spatial and temporal scale across two summers (2020-2021). We used anonymized cellphone data from SafeGraph's neighborhood patterns data set and gridded temperature data from gridMET, and analyzed the influence of incremental changes in temperature on mobility rate (i.e., visits per capita) using a panel regression with fixed effects. This strategy enabled us to control for spatial and temporal variability across the studied region. Our analysis suggested that all areas exhibited lower mobility rate in response to higher summer temperatures. We then explored how several additional variables altered these results. Extremely hot days resulted in faster mobility declines with increasing temperatures. Weekdays were often more resistant to temperature changes when compared to the weekend. In addition, the rate of decrease in mobility in response to high temperature was significantly greater among the wealthiest census block groups compared with the least wealthy. Further, the least mobile locations experienced significant differences in mobility response compared to the rest of the data set. Given the fundamental differences in the mobility response to temperature across most of our additive variables, our results are relevant for future mobility studies in the region.

  View details for DOI 10.1029/2022GH000772

  View details for PubMedID 37287701

  View details for PubMedCentralID PMC10243210

• Data-driven predictions of the time remaining until critical global warming thresholds are reached. Proceedings of the National Academy of Sciences of the United States of America Diffenbaugh, N. S., Barnes, E. A. 2023; 120 (6): e2207183120

  Abstract

  Leveraging artificial neural networks (ANNs) trained on climate model output, we use the spatial pattern of historical temperature observations to predict the time until critical global warming thresholds are reached. Although no observations are used during the training, validation, or testing, the ANNs accurately predict the timing of historical global warming from maps of historical annual temperature. The central estimate for the 1.5°C global warming threshold is between 2033 and 2035, including a ±1sigma range of 2028 to 2039 in the Intermediate (SSP2-4.5) climate forcing scenario, consistent with previous assessments. However, our data-driven approach also suggests a substantial probability of exceeding the 2°C threshold even in the Low (SSP1-2.6) climate forcing scenario. While there are limitations to our approach, our results suggest a higher likelihood of reaching 2°C in the Low scenario than indicated in some previous assessments-though the possibility that 2°C could be avoided is not ruled out. Explainable AI methods reveal that the ANNs focus on particular geographic regions to predict the time until the global threshold is reached. Our framework provides a unique, data-driven approach for quantifying the signal of climate change in historical observations and for constraining the uncertainty in climate model projections. Given the substantial existing evidence of accelerating risks to natural and human systems at 1.5°C and 2°C, our results provide further evidence for high-impact climate change over the next three decades.

  View details for DOI 10.1073/pnas.2207183120

  View details for PubMedID 36716375

• Attributing Past Carbon Fluxes to CO2 and Climate Change: Respiration Response to CO2 Fertilization Shifts Regional Distribution of the Carbon Sink Global Biogeochemical Cycles Quentin, G. R., Famiglietti, C. A., et al 2023

  View details for DOI 10.1029/2022GB007478

• Quantifying the Relationship Between Atmospheric River Origin Conditions and Landfall Temperature JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Gonzales, K. R., Swain, D. L., Roop, H. A., Diffenbaugh, N. S. 2022; 127 (20)

  View details for DOI 10.1029/2022JD037284

  View details for Web of Science ID 000871714600001

• Potential for perceived failure of stratospheric aerosol injection deployment. Proceedings of the National Academy of Sciences of the United States of America Keys, P. W., Barnes, E. A., Diffenbaugh, N. S., Hurrell, J. W., Bell, C. M. 2022; 119 (40): e2210036119

  Abstract

  As anthropogenic activities warm the Earth, the fundamental solution of reducing greenhouse gas emissions remains elusive. Given this mitigation gap, global warming may lead to intolerable climate changes as adaptive capacity is exceeded. Thus, there is emerging interest in solar radiation modification, which is the process of deliberately increasing Earth's albedo to cool the planet. Stratospheric aerosol injection (SAI)-the theoretical deployment of particles in the stratosphere to enhance reflection of incoming solar radiation-is one strategy to slow, pause, or reverse global warming. If SAI is ever pursued, it will likely be for a specific aim, such as affording time to implement mitigation strategies, lessening extremes, or reducing the odds of reaching a biogeophysical tipping point. Using an ensemble climate model experiment that simulates the deployment of SAI in the context of an intermediate greenhouse gas trajectory, we quantified the probability that internal climate variability masks the effectiveness of SAI deployment on regional temperatures. We found that while global temperature was stabilized, substantial land areas continued to experience warming. For example, in the SAI scenario we explored, up to 55% of the global population experienced rising temperatures over the decade following SAI deployment and large areas exhibited high probability of extremely hot years. These conditions could cause SAI to be perceived as a failure. Countries with the largest economies experienced some of the largest probabilities of this perceived failure. The potential for perceived failure could therefore have major implications for policy decisions in the years immediately following SAI deployment.

  View details for DOI 10.1073/pnas.2210036119

  View details for PubMedID 36166478

• Plant-water sensitivity regulates wildfire vulnerability. Nature ecology & evolution Rao, K., Williams, A. P., Diffenbaugh, N. S., Yebra, M., Konings, A. G. 2022

  Abstract

  Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2=0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50% faster during 1990-2010 than in other wildland-urban interfaces and because VPD has risen most rapidly in these vulnerable areas. As plant-water sensitivity is strongly linked to wildfire vulnerability, accounting for ecophysiological controls should improve wildfire forecasts. If recent trends in VPD and demographic shifts continue, human wildfire risk will probably continue to increase.

  View details for DOI 10.1038/s41559-021-01654-2

  View details for PubMedID 35132185

• COVID-19 and the Environment: Short-Run and Potential Long-Run Impacts ANNUAL REVIEW OF ENVIRONMENT AND RESOURCES Diffenbaugh, N. S. 2022; 47: 65-90

  View details for DOI 10.1146/annurev-environ-120920-125207

  View details for Web of Science ID 000869731800004

• Atmospheric variability contributes to increasing wildfire weather but not as much as global warming. Proceedings of the National Academy of Sciences of the United States of America Diffenbaugh, N. S., Konings, A. G., Field, C. B. 2021; 118 (46)

  View details for DOI 10.1073/pnas.2117876118

  View details for PubMedID 34764227

• On the impossibility of extreme event thresholds in the absence of global warming ENVIRONMENTAL RESEARCH LETTERS Diffenbaugh, N. S., Davenport, F. 2021; 16 (11)

  View details for DOI 10.1088/1748-9326/ac2f1a

  View details for Web of Science ID 000716130300001

• Using Machine Learning to Analyze Physical Causes of Climate Change: A Case Study of US Midwest Extreme Precipitation GEOPHYSICAL RESEARCH LETTERS Davenport, F., Diffenbaugh, N. S. 2021; 48 (15)

  View details for DOI 10.1029/2021GL093787

  View details for Web of Science ID 000683512200009

• Historical warming has increased US crop insurance losses ENVIRONMENTAL RESEARCH LETTERS Diffenbaugh, N. S., Davenport, F., Burke, M. 2021; 16 (8)

  View details for DOI 10.1088/1748-9326/ac1223

  View details for Web of Science ID 000678348500001

• The Atlantic Jet Response to Stratospheric Events: A Regime Perspective JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Goss, M., Lindgren, E. A., Sheshadri, A., Diffenbaugh, N. S. 2021; 126 (7)

  View details for DOI 10.1029/2020JD033358

  View details for Web of Science ID 000640969000003

• Contribution of historical precipitation change to US flood damages. Proceedings of the National Academy of Sciences of the United States of America Davenport, F. V., Burke, M., Diffenbaugh, N. S. 2021; 118 (4)

  Abstract

  Precipitation extremes have increased across many regions of the United States, with further increases anticipated in response to additional global warming. Quantifying the impact of these precipitation changes on flood damages is necessary to estimate the costs of climate change. However, there is little empirical evidence linking changes in precipitation to the historically observed increase in flood losses. We use >6,600 reports of state-level flood damage to quantify the historical relationship between precipitation and flood damages in the United States. Our results show a significant, positive effect of both monthly and 5-d state-level precipitation on state-level flood damages. In addition, we find that historical precipitation changes have contributed approximately one-third of cumulative flood damages over 1988 to 2017 (primary estimate 36%; 95% CI 20 to 46%), with the cumulative impact of precipitation change totaling $73 billion (95% CI 39 to $91 billion). Further, climate models show that anthropogenic climate forcing has increased the probability of exceeding precipitation thresholds at the extremely wet quantiles that are responsible for most flood damages. Climate models project continued intensification of wet conditions over the next three decades, although a trajectory consistent with UN Paris Agreement goals significantly curbs that intensification. Taken together, our results quantify the contribution of precipitation trends to recent increases in flood damages, advance estimates of the costs associated with historical greenhouse gas emissions, and provide further evidence that lower levels of future warming are very likely to reduce financial losses relative to the current global warming trajectory.

  View details for DOI 10.1073/pnas.2017524118

  View details for PubMedID 33431652

• Quantifying the Effect of Precipitation on Landslide Hazard in Urbanized and Non-Urbanized Areas Geophysical Research Letters Johnston, E. C., Davenport, F. V., Wang, L., Caers, J. K., Muthukrishnan, S., Burke, M., Diffenbaugh, N. S. 2021; 48 (16)

  View details for DOI 10.1029/2021GL094038

• Moisture- Versus Wind-Dominated Flavors of Atmospheric Rivers GEOPHYSICAL RESEARCH LETTERS Gonzales, K. R., Swain, D. L., Barnes, E. A., Diffenbaugh, N. S. 2020; 47 (23)

  View details for DOI 10.1029/2020GL090042

  View details for Web of Science ID 000598677000060

• Climate change is increasing the likelihood of extreme autumn wildfire conditions across California ENVIRONMENTAL RESEARCH LETTERS Goss, M., Swain, D. L., Abatzoglou, J. T., Sarhadi, A., Kolden, C. A., Williams, A., Diffenbaugh, N. S. 2020; 15 (9)

  View details for DOI 10.1088/1748-9326/ab83a7

  View details for Web of Science ID 000563496700001

• The COVID-19 lockdowns: a window into the Earth System NATURE REVIEWS EARTH & ENVIRONMENT Diffenbaugh, N. S., Field, C. B., Appel, E. A., Azevedo, I. L., Baldocchi, D. D., Burke, M., Burney, J. A., Ciais, P., Davis, S. J., Fiore, A. M., Fletcher, S. M., Hertel, T. W., Horton, D. E., Hsiang, S. M., Jackson, R. B., Jin, X., Levi, M., Lobell, D. B., McKinley, G. A., Moore, F. C., Montgomery, A., Nadeau, K. C., Pataki, D. E., Randerson, J. T., Reichstein, M., Schnell, J. L., Seneviratne, S., Singh, D., Steiner, A. L., Wong-Parodi, G. 2020; 1 (9): 470-481

  View details for DOI 10.1038/s43017-020-0079-1

  View details for Web of Science ID 000649448400008

• Landfalling Droughts: Global Tracking of Moisture Deficits From the Oceans Onto Land WATER RESOURCES RESEARCH Herrera-Estrada, J. E., Diffenbaugh, N. S. 2020; 56 (9)

  View details for DOI 10.1029/2019WR026877

  View details for Web of Science ID 000578452200051

• Attributing Extreme Events to Climate Change: A New Frontier in a Warming World ONE EARTH Swain, D. L., Singh, D., Touma, D., Diffenbaugh, N. S. 2020; 2 (6): 522-527

  View details for DOI 10.1016/j.oneear.2020.05.011

  View details for Web of Science ID 000645255700011

• Doubling of US Population Exposure to Climate Extremes by 2050 EARTHS FUTURE Batibeniz, F., Ashfaq, M., Diffenbaugh, N. S., Key, K., Evans, K. J., Turuncoglu, U., Onol, B. 2020; 8 (4)

  View details for DOI 10.1029/2019EF001421

  View details for Web of Science ID 000530038700007

• Verification of extreme event attribution: Using out-of-sample observations to assess changes in probabilities of unprecedented events. Science advances Diffenbaugh, N. S. 2020; 6 (12): eaay2368

  Abstract

  Independent verification of anthropogenic influence on specific extreme climate events remains elusive. This study presents a framework for such verification. This framework reveals that previously published results based on a 1961-2005 attribution period frequently underestimate the influence of global warming on the probability of unprecedented extremes during the 2006-2017 period. This underestimation is particularly pronounced for hot and wet events, with greater uncertainty for dry events. The underestimation is reflected in discrepancies between probabilities predicted during the attribution period and frequencies observed during the out-of-sample verification period. These discrepancies are most explained by increases in climate forcing between the attribution and verification periods, suggesting that 21st-century global warming has substantially increased the probability of unprecedented hot and wet events. Hence, the use of temporally lagged periods for attribution-and, more broadly, for extreme event probability quantification-can cause underestimation of historical impacts, and current and future risks.

  View details for DOI 10.1126/sciadv.aay2368

  View details for PubMedID 32206708

• Flood Size Increases Nonlinearly Across the Western United States in Response to Lower Snow-Precipitation Ratios WATER RESOURCES RESEARCH Davenport, F. V., Herrera-Estrada, J. E., Burke, M., Diffenbaugh, N. S. 2020; 56 (1)

  View details for DOI 10.1029/2019WR025571

  View details for Web of Science ID 000520132500022

• Variations in the Intensity and Spatial Extent of Tropical Cyclone Precipitation GEOPHYSICAL RESEARCH LETTERS Touma, D., Stevenson, S., Camargo, S. J., Horton, D. E., Diffenbaugh, N. S. 2019

  View details for DOI 10.1029/2019GL083452

  View details for Web of Science ID 000500529200001

• Recent Warming of Landfalling Atmospheric Rivers Along the West Coast of the United States JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Gonzales, K. R., Swain, D. L., Nardi, K. M., Barnes, E. A., Diffenbaugh, N. S. 2019; 124 (13): 6810–26

  View details for DOI 10.1029/2018JD029860

  View details for Web of Science ID 000477580200010

• Disentangling the influence of local and remote anthropogenic aerosols on South Asian monsoon daily rainfall characteristics CLIMATE DYNAMICS Singh, D., Bollasina, M., Ting, M., Diffenbaugh, N. S. 2019; 52 (9-10): 6301–20

  View details for DOI 10.1007/s00382-018-4512-9

  View details for Web of Science ID 000465441400070

• Global warming has increased global economic inequality. Proceedings of the National Academy of Sciences of the United States of America Diffenbaugh, N. S., Burke, M. 2019

  Abstract

  Understanding the causes of economic inequality is critical for achieving equitable economic development. To investigate whether global warming has affected the recent evolution of inequality, we combine counterfactual historical temperature trajectories from a suite of global climate models with extensively replicated empirical evidence of the relationship between historical temperature fluctuations and economic growth. Together, these allow us to generate probabilistic country-level estimates of the influence of anthropogenic climate forcing on historical economic output. We find very high likelihood that anthropogenic climate forcing has increased economic inequality between countries. For example, per capita gross domestic product (GDP) has been reduced 17-31% at the poorest four deciles of the population-weighted country-level per capita GDP distribution, yielding a ratio between the top and bottom deciles that is 25% larger than in a world without global warming. As a result, although between-country inequality has decreased over the past half century, there is 90% likelihood that global warming has slowed that decrease. The primary driver is the parabolic relationship between temperature and economic growth, with warming increasing growth in cool countries and decreasing growth in warm countries. Although there is uncertainty in whether historical warming has benefited some temperate, rich countries, for most poor countries there is >90% likelihood that per capita GDP is lower today than if global warming had not occurred. Thus, our results show that, in addition to not sharing equally in the direct benefits of fossil fuel use, many poor countries have been significantly harmed by the warming arising from wealthy countries' energy consumption.

  View details for PubMedID 31010922

• Reply to Rosen: Temperature-growth relationship is robust. Proceedings of the National Academy of Sciences of the United States of America Diffenbaugh, N. S., Burke, M. n. 2019

  View details for DOI 10.1073/pnas.1908772116

  View details for PubMedID 31375623

• Strengthened scientific support for the Endangerment Finding for atmospheric greenhouse gases. Science (New York, N.Y.) Duffy, P. B., Field, C. B., Diffenbaugh, N. S., Doney, S. C., Dutton, Z., Goodman, S., Heinzerling, L., Hsiang, S., Lobell, D. B., Mickley, L. J., Myers, S., Natali, S. M., Parmesan, C., Tierney, S., Williams, A. P. 2018

  Abstract

  We assess scientific evidence that has emerged since the U.S. Environmental Protection Agency's 2009 Endangerment Finding for six well-mixed greenhouse gases, and find that this new evidence lends increased support to the conclusion that these gases pose a danger to public health and welfare. Newly available evidence about a wide range of observed and projected impacts strengthens the association between risk of some of these impacts and anthropogenic climate change; indicates that some impacts or combinations of impacts have the potential to be more severe than previously understood; and identifies substantial risk of additional impacts through processes and pathways not considered in the endangerment finding.

  View details for PubMedID 30545843

• Response of electricity sector air pollution emissions to drought conditions in the western United States ENVIRONMENTAL RESEARCH LETTERS Herrera-Estrada, J. E., Diffenbaugh, N. S., Wagner, F., Craft, A., Sheffield, J. 2018; 13 (12)

  View details for DOI 10.1088/1748-9326/aaf07b

  View details for Web of Science ID 000454316300002

• Multidimensional risk in a nonstationary climate: Joint probability of increasingly severe warm and dry conditions. Science advances Sarhadi, A., Ausin, M. C., Wiper, M. P., Touma, D., Diffenbaugh, N. S. 2018; 4 (11): eaau3487

  Abstract

  We present a framework for quantifying the spatial and temporal co-occurrence of climate stresses in a nonstationary climate. We find that, globally, anthropogenic climate forcing has doubled the joint probability of years that are both warm and dry in the same location (relative to the 1961-1990 baseline). In addition, the joint probability that key crop and pasture regions simultaneously experience severely warm conditions in conjunction with dry years has also increased, including high statistical confidence that human influence has increased the probability of previously unprecedented co-occurring combinations. Further, we find that ambitious emissions mitigation, such as that in the United Nations Paris Agreement, substantially curbs increases in the probability that extremely hot years co-occur with low precipitation simultaneously in multiple regions. Our methodology can be applied to other climate variables, providing critical insight for a number of sectors that are accustomed to deploying resources based on historical probabilities.

  View details for PubMedID 30498780

• Can ENSO-Like Convection Force an ENSO-Like Extratropical Response on Subseasonal Time Scales? JOURNAL OF CLIMATE Goss, M., Lee, S., Feldstein, S. B., Diffenbaugh, N. S. 2018; 31 (20): 8339–49

  View details for DOI 10.1175/JCLI-D-17-0771.1

  View details for Web of Science ID 000443930800002

• Characterizing the Spatial Scales of Extreme Daily Precipitation in the United States JOURNAL OF CLIMATE Touma, D., Michalak, A. M., Swain, D. L., Diffenbaugh, N. S. 2018; 31 (19): 8023–37

  View details for DOI 10.1175/JCLI-D-18-0019.1

  View details for Web of Science ID 000442564700002

• Large potential reduction in economic damages under UN mitigation targets NATURE Burke, M., Davis, W., Diffenbaugh, N. S. 2018; 557 (7706): 549-+

  Abstract

  International climate change agreements typically specify global warming thresholds as policy targets 1 , but the relative economic benefits of achieving these temperature targets remain poorly understood2,3. Uncertainties include the spatial pattern of temperature change, how global and regional economic output will respond to these changes in temperature, and the willingness of societies to trade present for future consumption. Here we combine historical evidence 4 with national-level climate 5 and socioeconomic 6 projections to quantify the economic damages associated with the United Nations (UN) targets of 1.5 °C and 2 °C global warming, and those associated with current UN national-level mitigation commitments (which together approach 3 °C warming 7 ). We find that by the end of this century, there is a more than 75% chance that limiting warming to 1.5 °C would reduce economic damages relative to 2 °C, and a more than 60% chance that the accumulated global benefits will exceed US$20 trillion under a 3% discount rate (2010 US dollars). We also estimate that 71% of countries-representing 90% of the global population-have a more than 75% chance of experiencing reduced economic damages at 1.5 °C, with poorer countries benefiting most. Our results could understate the benefits of limiting warming to 1.5 °C if unprecedented extreme outcomes, such as large-scale sea level rise 8 , occur for warming of 2 °C but not for warming of 1.5 °C. Inclusion of other unquantified sources of uncertainty, such as uncertainty in secular growth rates beyond that contained in existing socioeconomic scenarios, could also result in less precise impact estimates. We find considerably greater reductions in global economic output beyond 2 °C. Relative to a world that did not warm beyond 2000-2010 levels, we project 15%-25% reductions in per capita output by 2100 for the 2.5-3 °C of global warming implied by current national commitments 7 , and reductions of more than 30% for 4 °C warming. Our results therefore suggest that achieving the 1.5 °C target is likely to reduce aggregate damages and lessen global inequality, and that failing to meet the 2 °C target is likely to increase economic damages substantially.

  View details for PubMedID 29795251

• Unprecedented climate events: Historical changes, aspirational targets, and national commitments. Science advances Diffenbaugh, N. S., Singh, D., Mankin, J. S. 2018; 4 (2): eaao3354

  Abstract

  The United Nations Paris Agreement creates a specific need to compare consequences of cumulative emissions for pledged national commitments and aspirational targets of 1.5° to 2°C global warming. We find that humans have already increased the probability of historically unprecedented hot, warm, wet, and dry extremes, including over 50 to 90% of North America, Europe, and East Asia. Emissions consistent with national commitments are likely to cause substantial and widespread additional increases, including more than fivefold for warmest night over ~50% of Europe and >25% of East Asia and more than threefold for wettest days over >35% of North America, Europe, and East Asia. In contrast, meeting aspirational targets to keep global warming below 2°C reduces the area experiencing more than threefold increases to <10% of most regions studied. However, large areas-including >90% of North America, Europe, East Asia, and much of the tropics-still exhibit sizable increases in the probability of record-setting hot, wet, and/or dry events.

  View details for PubMedID 29457133

• Widespread persistent changes to temperature extremes occurred earlier than predicted SCIENTIFIC REPORTS Li, C., Fang, Y., Caldeira, K., Zhang, X., Diffenbaugh, N. S., Michalak, A. M. 2018; 8: 1007

  Abstract

  A critical question for climate mitigation and adaptation is to understand when and where the signal of changes to climate extremes have persistently emerged or will emerge from the background noise of climate variability. Here we show observational evidence that such persistent changes to temperature extremes have already occurred over large parts of the Earth. We further show that climate models forced with natural and anthropogenic historical forcings underestimate these changes. In particular, persistent changes have emerged in observations earlier and over a larger spatial extent than predicted by models. The delayed emergence in the models is linked to a combination of simulated change ('signal') that is weaker than observed, and simulated variability ('noise') that is greater than observed. Over regions where persistent changes had not occurred by the year 2000, we find that most of the observed signal-to-noise ratios lie within the 16-84% range of those simulated. Examination of simulations with and without anthropogenic forcings provides evidence that the observed changes are more likely to be anthropogenic than nature in origin. Our findings suggest that further changes to temperature extremes over parts of the Earth are likely to occur earlier than projected by the current climate models.

  View details for PubMedID 29343828

• Remote Linkages to Anomalous Winter Atmospheric Ridging Over the Northeastern Pacific JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Swain, D. L., Singh, D., Horton, D. E., Mankin, J. S., Ballard, T. C., Diffenbaugh, N. S. 2017; 122 (22): 12194–209

  View details for DOI 10.1002/2017JD026575

  View details for Web of Science ID 000418084500005

• Quantifying the influence of global warming on unprecedented extreme climate events PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Diffenbaugh, N. S., Singh, D., Mankin, J. S., Horton, D. E., Swain, D. L., Touma, D., Charland, A., Liu, Y., Haugen, M., Tsiang, M., Rajaratnam, B. 2017; 114 (19): 4881-4886

  Abstract

  Efforts to understand the influence of historical global warming on individual extreme climate events have increased over the past decade. However, despite substantial progress, events that are unprecedented in the local observational record remain a persistent challenge. Leveraging observations and a large climate model ensemble, we quantify uncertainty in the influence of global warming on the severity and probability of the historically hottest month, hottest day, driest year, and wettest 5-d period for different areas of the globe. We find that historical warming has increased the severity and probability of the hottest month and hottest day of the year at >80% of the available observational area. Our framework also suggests that the historical climate forcing has increased the probability of the driest year and wettest 5-d period at 57% and 41% of the observed area, respectively, although we note important caveats. For the most protracted hot and dry events, the strongest and most widespread contributions of anthropogenic climate forcing occur in the tropics, including increases in probability of at least a factor of 4 for the hottest month and at least a factor of 2 for the driest year. We also demonstrate the ability of our framework to systematically evaluate the role of dynamic and thermodynamic factors such as atmospheric circulation patterns and atmospheric water vapor, and find extremely high statistical confidence that anthropogenic forcing increased the probability of record-low Arctic sea ice extent.

  View details for DOI 10.1073/pnas.1618082114

  View details for Web of Science ID 000400818400030

  View details for PubMedID 28439005

• The Role of Plant CO2 Physiological Forcing in Shaping Future Daily-Scale Precipitation JOURNAL OF CLIMATE Skinner, C. B., Poulsen, C. J., Chadwick, R., Diffenbaugh, N. S., Fiorella, R. P. 2017; 30 (7): 2319-2340

  View details for DOI 10.1175/JCLI-D-16-0603.1

  View details for Web of Science ID 000399678400003

• Influence of internal variability on population exposure to hydroclimatic changes. Environmental research letters : ERL [Web site] Mankin, J. S., Viviroli, D., Mekonnen, M. M., Hoekstra, A. Y., Horton, R. M., Smerdon, J. E., Diffenbaugh, N. S. 2017; 12 (4): 044007

  Abstract

  Future freshwater supply, human water demand, and people's exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and 'irreducible' uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation in a basin. We calculate that by 2060, ~31%-35% of the global population will be exposed to >50% probability of hydroclimatic deficit increases that exceed existing hydrological storage, with up to 9% of people exposed to >90% probability. However, internal variability, which is an irreducible uncertainty in climate model predictions that is under-sampled in water resource projections, creates substantial uncertainty in predicted exposure: ~86%-91% of people will reside where irreducible uncertainty spans the potential for both increases and decreases in sub-annual water deficits. In one population scenario, changes in exposure to large hydroclimate deficits vary from -3% to +6% of global population, a range arising entirely from internal variability. The uncertainty in risk arising from irreducible uncertainty in the precise pattern of hydroclimatic change, which is typically conflated with other uncertainties in projections, is critical for climate risk management that seeks to optimize adaptations that are robust to the full set of potential real-world outcomes.

  View details for DOI 10.1088/1748-9326/aa5efc

  View details for PubMedID 32849911

  View details for PubMedCentralID PMC7446950

• Influence of internal variability on population exposure to hydroclimatic changes ENVIRONMENTAL RESEARCH LETTERS Mankin, J. S., Viviroli, D., Mekonnen, M. M., Hoekstra, A. Y., Horton, R. M., Smerdon, J. E., Diffenbaugh, N. S. 2017; 12 (4)

  View details for DOI 10.1088/1748-9326/aa5efc

  View details for Web of Science ID 000397804000007

• Drought and immunity determine the intensity of West Nile virus epidemics and climate change impacts PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Paull, S. H., Horton, D. E., Ashfaq, M., Rastogi, D., Kramer, L. D., Diffenbaugh, N. S., Kilpatrick, A. M. 2017; 284 (1848)

  Abstract

  The effect of global climate change on infectious disease remains hotly debated because multiple extrinsic and intrinsic drivers interact to influence transmission dynamics in nonlinear ways. The dominant drivers of widespread pathogens, like West Nile virus, can be challenging to identify due to regional variability in vector and host ecology, with past studies producing disparate findings. Here, we used analyses at national and state scales to examine a suite of climatic and intrinsic drivers of continental-scale West Nile virus epidemics, including an empirically derived mechanistic relationship between temperature and transmission potential that accounts for spatial variability in vectors. We found that drought was the primary climatic driver of increased West Nile virus epidemics, rather than within-season or winter temperatures, or precipitation independently. Local-scale data from one region suggested drought increased epidemics via changes in mosquito infection prevalence rather than mosquito abundance. In addition, human acquired immunity following regional epidemics limited subsequent transmission in many states. We show that over the next 30 years, increased drought severity from climate change could triple West Nile virus cases, but only in regions with low human immunity. These results illustrate how changes in drought severity can alter the transmission dynamics of vector-borne diseases.

  View details for DOI 10.1098/rspb.2016.2078

  View details for Web of Science ID 000393750000004

  View details for PubMedID 28179512

• Probability of emergence of novel temperature regimes at different levels of cumulative carbon emissions FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Diffenbaugh, N. S., Charland, A. 2016; 14 (8): 418-423

  View details for DOI 10.1002/fee.1320

  View details for Web of Science ID 000386123600012

• Regional atmospheric CO2 inversion reveals seasonal and geographic differences in Amazon net biome exchange. Global change biology Alden, C. B., Miller, J. B., Gatti, L. V., Gloor, M. M., Guan, K., Michalak, A. M., van der Laan-Luijkx, I. T., Touma, D., Andrews, A., Basso, L. S., Correia, C. S., Domingues, L. G., Joiner, J., Krol, M. C., Lyapustin, A. I., Peters, W., Shiga, Y. P., Thoning, K., van der Velde, I. R., van Leeuwen, T. T., Yadav, V., Diffenbaugh, N. S. 2016; 22 (10): 3427-3443

  Abstract

  Understanding tropical rainforest carbon exchange and its response to heat and drought is critical for quantifying the effects of climate change on tropical ecosystems, including global climate-carbon feedbacks. Of particular importance for the global carbon budget is net biome exchange of CO2 with the atmosphere (NBE), which represents nonfire carbon fluxes into and out of biomass and soils. Subannual and sub-Basin Amazon NBE estimates have relied heavily on process-based biosphere models, despite lack of model agreement with plot-scale observations. We present a new analysis of airborne measurements that reveals monthly, regional-scale (~1-8 × 10(6)  km(2) ) NBE variations. We develop a regional atmospheric CO2 inversion that provides the first analysis of geographic and temporal variability in Amazon biosphere-atmosphere carbon exchange and that is minimally influenced by biosphere model-based first guesses of seasonal and annual mean fluxes. We find little evidence for a clear seasonal cycle in Amazon NBE but do find NBE sensitivity to aberrations from long-term mean climate. In particular, we observe increased NBE (more carbon emitted to the atmosphere) associated with heat and drought in 2010, and correlations between wet season NBE and precipitation (negative correlation) and temperature (positive correlation). In the eastern Amazon, pulses of increased NBE persisted through 2011, suggesting legacy effects of 2010 heat and drought. We also identify regional differences in postdrought NBE that appear related to long-term water availability. We examine satellite proxies and find evidence for higher gross primary productivity (GPP) during a pulse of increased carbon uptake in 2011, and lower GPP during a period of increased NBE in the 2010 dry season drought, but links between GPP and NBE changes are not conclusive. These results provide novel evidence of NBE sensitivity to short-term temperature and moisture extremes in the Amazon, where monthly and sub-Basin estimates have not been previously available.

  View details for DOI 10.1111/gcb.13305

  View details for PubMedID 27124119

• Recent amplification of the North American winter temperature dipole. Journal of geophysical research. Atmospheres : JGR Singh, D., Swain, D. L., Mankin, J. S., Horton, D. E., Thomas, L. N., Rajaratnam, B., Diffenbaugh, N. S. 2016; 121 (17): 9911-9928

  Abstract

  During the winters of 2013-2014 and 2014-2015, anomalously warm temperatures in western North America and anomalously cool temperatures in eastern North America resulted in substantial human and environmental impacts. Motivated by the impacts of these concurrent temperature extremes and the intrinsic atmospheric linkage between weather conditions in the western and eastern United States, we investigate the occurrence of concurrent "warm-West/cool-East" surface temperature anomalies, which we call the "North American winter temperature dipole." We find that, historically, warm-West/cool-East dipole conditions have been associated with anomalous mid-tropospheric ridging over western North America and downstream troughing over eastern North America. We also find that the occurrence and severity of warm-West/cool-East events have increased significantly between 1980 and 2015, driven largely by an increase in the frequency with which high-amplitude "ridge-trough" wave patterns result in simultaneous severe temperature conditions in both the West and East. Using a large single-model ensemble of climate simulations, we show that the observed positive trend in the warm-West/cool-East events is attributable to historical anthropogenic emissions including greenhouse gases, but that the co-occurrence of extreme western warmth and eastern cold will likely decrease in the future as winter temperatures warm dramatically across the continent, thereby reducing the occurrence of severely cold conditions in the East. Although our analysis is focused on one particular region, our analysis framework is generally transferable to the physical conditions shaping different types of extreme events around the globe.

  View details for DOI 10.1002/2016JD025116

  View details for PubMedID 27840780

  View details for PubMedCentralID PMC5095811

• Recent amplification of the North American winter temperature dipole JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Singh, D., Swain, D. L., Mankin, J. S., Horton, D. E., Thomas, L. N., Rajaratnam, B., Diffenbaugh, N. S. 2016; 121 (17): 9911-9928

  Abstract

  During the winters of 2013-2014 and 2014-2015, anomalously warm temperatures in western North America and anomalously cool temperatures in eastern North America resulted in substantial human and environmental impacts. Motivated by the impacts of these concurrent temperature extremes and the intrinsic atmospheric linkage between weather conditions in the western and eastern United States, we investigate the occurrence of concurrent "warm-West/cool-East" surface temperature anomalies, which we call the "North American winter temperature dipole." We find that, historically, warm-West/cool-East dipole conditions have been associated with anomalous mid-tropospheric ridging over western North America and downstream troughing over eastern North America. We also find that the occurrence and severity of warm-West/cool-East events have increased significantly between 1980 and 2015, driven largely by an increase in the frequency with which high-amplitude "ridge-trough" wave patterns result in simultaneous severe temperature conditions in both the West and East. Using a large single-model ensemble of climate simulations, we show that the observed positive trend in the warm-West/cool-East events is attributable to historical anthropogenic emissions including greenhouse gases, but that the co-occurrence of extreme western warmth and eastern cold will likely decrease in the future as winter temperatures warm dramatically across the continent, thereby reducing the occurrence of severely cold conditions in the East. Although our analysis is focused on one particular region, our analysis framework is generally transferable to the physical conditions shaping different types of extreme events around the globe.

  View details for DOI 10.1002/2016JD025116

  View details for Web of Science ID 000384823000024

  View details for PubMedCentralID PMC5095811

• Dislocated interests and climate change ENVIRONMENTAL RESEARCH LETTERS Davis, S. J., Diffenbaugh, N. 2016; 11 (6)

  View details for DOI 10.1088/1748-9326/11/6/061001

  View details for Web of Science ID 000378812200001

• Trends in atmospheric patterns conducive to seasonal precipitation and temperature extremes in California. Science advances Swain, D. L., Horton, D. E., Singh, D., Diffenbaugh, N. S. 2016; 2 (4)

  Abstract

  Recent evidence suggests that changes in atmospheric circulation have altered the probability of extreme climate events in the Northern Hemisphere. We investigate northeastern Pacific atmospheric circulation patterns that have historically (1949-2015) been associated with cool-season (October-May) precipitation and temperature extremes in California. We identify changes in occurrence of atmospheric circulation patterns by measuring the similarity of the cool-season atmospheric configuration that occurred in each year of the 1949-2015 period with the configuration that occurred during each of the five driest, wettest, warmest, and coolest years. Our analysis detects statistically significant changes in the occurrence of atmospheric patterns associated with seasonal precipitation and temperature extremes. We also find a robust increase in the magnitude and subseasonal persistence of the cool-season West Coast ridge, resulting in an amplification of the background state. Changes in both seasonal mean and extreme event configurations appear to be caused by a combination of spatially nonuniform thermal expansion of the atmosphere and reinforcing trends in the pattern of sea level pressure. In particular, both thermal expansion and sea level pressure trends contribute to a notable increase in anomalous northeastern Pacific ridging patterns similar to that observed during the 2012-2015 California drought. Collectively, our empirical findings suggest that the frequency of atmospheric conditions like those during California's most severely dry and hot years has increased in recent decades, but not necessarily at the expense of patterns associated with extremely wet years.

  View details for DOI 10.1126/sciadv.1501344

  View details for PubMedID 27051876

  View details for PubMedCentralID PMC4820386

• Observed and projected climate trends and hotspots across the National Ecological Observatory Network regions FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Anderegg, W. R., Diffenbaugh, N. S. 2015; 13 (10): 547-552

  View details for DOI 10.1890/150159

  View details for Web of Science ID 000365829600013

• Debunking the climate hiatus CLIMATIC CHANGE Rajaratnam, B., Romano, J., Tsiang, M., Diffenbaugh, N. S. 2015; 133 (2): 129-140

  View details for DOI 10.1007/s10584-015-1495-y

  View details for Web of Science ID 000363483800001

• The potential for snow to supply human water demand in the present and future ENVIRONMENTAL RESEARCH LETTERS Mankin, J. S., Viviroli, D., Singh, D., Hoekstra, A. Y., Diffenbaugh, N. S. 2015; 10 (11)

  View details for DOI 10.1088/1748-9326/10/11/114016

  View details for Web of Science ID 000367249900020

• Future property damage from flooding: sensitivities to economy and climate change CLIMATIC CHANGE Liu, J., Hertel, T. W., Diffenbaugh, N. S., Delgado, M. S., Ashfaq, M. 2015; 132 (4): 741-749

  View details for DOI 10.1007/s10584-015-1478-z

  View details for Web of Science ID 000361799100022

• Rate and velocity of climate change caused by cumulative carbon emissions ENVIRONMENTAL RESEARCH LETTERS LoPresti, A., Charland, A., Woodard, D., Randerson, J., Diffenbaugh, N. S., Davis, S. J. 2015; 10 (9)

  View details for DOI 10.1088/1748-9326/10/9/095001

  View details for Web of Science ID 000367141000029

• Evaluation of Nonhydrostatic Simulations of Northeast Pacific Atmospheric Rivers and Comparison to in Situ Observations MONTHLY WEATHER REVIEW Swain, D. L., Lebassi-Habtezion, B., Diffenbaugh, N. S. 2015; 143 (9): 3556-3569

  View details for DOI 10.1175/MWR-D-15-0079.1

  View details for Web of Science ID 000360313800012

• Influence of temperature and precipitation variability on near-term snow trends CLIMATE DYNAMICS Mankin, J. S., Diffenbaugh, N. S. 2015; 45 (3-4): 1099-1116

  View details for DOI 10.1007/s00382-014-2357-4

  View details for Web of Science ID 000356807800035

• A multi-model and multi-index evaluation of drought characteristics in the 21st century JOURNAL OF HYDROLOGY Touma, D., Ashfaq, M., Nayak, M. A., Kao, S., Diffenbaugh, N. S. 2015; 526: 196-207

  View details for DOI 10.1016/j.jhydrol.2014.12.011

  View details for Web of Science ID 000355894700017

• Contribution of changes in atmospheric circulation patterns to extreme temperature trends. Nature Horton, D. E., Johnson, N. C., Singh, D., Swain, D. L., Rajaratnam, B., Diffenbaugh, N. S. 2015; 522 (7557): 465-469

  Abstract

  Surface weather conditions are closely governed by the large-scale circulation of the Earth's atmosphere. Recent increases in the occurrence of some extreme weather phenomena have led to multiple mechanistic hypotheses linking changes in atmospheric circulation to increasing probability of extreme events. However, observed evidence of long-term change in atmospheric circulation remains inconclusive. Here we identify statistically significant trends in the occurrence of atmospheric circulation patterns, which partially explain observed trends in surface temperature extremes over seven mid-latitude regions of the Northern Hemisphere. Using self-organizing map cluster analysis, we detect robust circulation pattern trends in a subset of these regions during both the satellite observation era (1979-2013) and the recent period of rapid Arctic sea-ice decline (1990-2013). Particularly substantial influences include the contribution of increasing trends in anticyclonic circulations to summer and autumn hot extremes over portions of Eurasia and North America, and the contribution of increasing trends in northerly flow to winter cold extremes over central Asia. Our results indicate that although a substantial portion of the observed change in extreme temperature occurrence has resulted from regional- and global-scale thermodynamic changes, the risk of extreme temperatures over some regions has also been altered by recent changes in the frequency, persistence and maximum duration of regional circulation patterns.

  View details for DOI 10.1038/nature14550

  View details for PubMedID 26108856

• Anthropogenic warming has increased drought risk in California. Proceedings of the National Academy of Sciences of the United States of America Diffenbaugh, N. S., Swain, D. L., Touma, D. 2015; 112 (13): 3931-3936

  Abstract

  California is currently in the midst of a record-setting drought. The drought began in 2012 and now includes the lowest calendar-year and 12-mo precipitation, the highest annual temperature, and the most extreme drought indicators on record. The extremely warm and dry conditions have led to acute water shortages, groundwater overdraft, critically low streamflow, and enhanced wildfire risk. Analyzing historical climate observations from California, we find that precipitation deficits in California were more than twice as likely to yield drought years if they occurred when conditions were warm. We find that although there has not been a substantial change in the probability of either negative or moderately negative precipitation anomalies in recent decades, the occurrence of drought years has been greater in the past two decades than in the preceding century. In addition, the probability that precipitation deficits co-occur with warm conditions and the probability that precipitation deficits produce drought have both increased. Climate model experiments with and without anthropogenic forcings reveal that human activities have increased the probability that dry precipitation years are also warm. Further, a large ensemble of climate model realizations reveals that additional global warming over the next few decades is very likely to create ∼100% probability that any annual-scale dry period is also extremely warm. We therefore conclude that anthropogenic warming is increasing the probability of co-occurring warm-dry conditions like those that have created the acute human and ecosystem impacts associated with the "exceptional" 2012-2014 drought in California.

  View details for DOI 10.1073/pnas.1422385112

  View details for PubMedID 25733875

  View details for PubMedCentralID PMC4386330

• Projecting changes in annual hydropower generation using regional runoff data: An assessment of the United States federal hydropower plants ENERGY Kao, S., Sale, M. J., Ashfaq, M., Martinez, R. U., Kaiser, D. P., Wei, Y., Diffenbaugh, N. S. 2015; 80: 239-250

  View details for DOI 10.1016/j.energy.2014.11.066

  View details for Web of Science ID 000349723500023

• Joint bias correction of temperature and precipitation in climate model simulations JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Li, C., Sinha, E., Horton, D. E., Diffenbaugh, N. S., Michalak, A. M. 2014; 119 (23): 13153-13162

  View details for DOI 10.1002/2014JD022514

  View details for Web of Science ID 000346907100007

• THE EXTRAORDINARY CALIFORNIA DROUGHT OF 2013/2014: CHARACTER, CONTEXT, AND THE ROLE OF CLIMATE CHANGE BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Swain, D. L., Tsiang, M., Haugen, M., Singh, D., Charland, A., Rajaratnam, B., Diffenbaugh, N. S. 2014; 95 (9): S3-S7

  View details for Web of Science ID 000344820500002

• SEVERE PRECIPITATION IN NORTHERN INDIA IN JUNE 2013: CAUSES, HISTORICAL CONTEXT, AND CHANGES IN PROBABILITY BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Singh, D., Horton, D. E., Tsiang, M., Haugen, M., Ashfaq, M., Mei, R., Rastogi, D., Johnson, N. C., Charland, A., Rajaratnam, B., Diffenbaugh, N. S. 2014; 95 (9): S58-S61

  View details for Web of Science ID 000344820500017

• Occurrence and persistence of future atmospheric stagnation events NATURE CLIMATE CHANGE Horton, D. E., Skinner, C. B., Singh, D., Diffenbaugh, N. S. 2014; 4 (8): 698-703

  View details for DOI 10.1038/NCLIMATE2272

  View details for Web of Science ID 000341568200023

• Occurrence and persistence of future atmospheric stagnation events. Nature climate change Horton, D. E., Skinner, C. B., Singh, D., Diffenbaugh, N. S. 2014; 4: 698-703

  Abstract

  Poor air quality causes an estimated 2.6 to 4.4 million premature deaths per year1-3. Hazardous conditions form when meteorological components allow the accumulation of pollutants in the near-surface atmosphere4-8. Global warming-driven changes to atmospheric circulation and the hydrological cycle9-13 are expected to alter the meteorological components that control pollutant build-up and dispersal5-8,14, but the magnitude, direction, geographic footprint, and public health impact of this alteration remain unclear7,8. We utilize an air stagnation index and an ensemble of bias-corrected climate model simulations to quantify the response of stagnation occurrence and persistence to global warming. Our analysis projects increases in stagnation occurrence that cover 55% of the current global population, with areas of increase affecting 10 times more people than areas of decrease. By the late-21st century, robust increases of up to 40 days per year are projected throughout the majority of the tropics and subtropics, as well as within isolated mid-latitude regions. Potential impacts over India, Mexico, and the western U.S. are particularly acute due to the intersection of large populations and increases in the persistence of stagnation events, including those of extreme duration. These results indicate that anthropogenic climate change is likely to alter the level of pollutant management required to meet future air quality targets.

  View details for DOI 10.1038/nclimate2272

  View details for PubMedID 25309627

  View details for PubMedCentralID PMC4190845

• Uncertainties in the timing of unprecedented climates. Nature Hawkins, E., Anderson, B., Diffenbaugh, N., Mahlstein, I., Betts, R., Hegerl, G., Joshi, M., Knutti, R., McNeall, D., Solomon, S., Sutton, R., Syktus, J., Vecchi, G. 2014; 511 (7507): E3-5

  View details for DOI 10.1038/nature13523

  View details for PubMedID 24990757

• Observed changes in extreme wet and dry spells during the South Asian summer monsoon season NATURE CLIMATE CHANGE Singh, D., Tsiang, M., Rajaratnam, B., Diffenbaugh, N. S. 2014; 4 (6): 456-461

  View details for DOI 10.1038/NCLIMATE2208

  View details for Web of Science ID 000337138700020

• Market-oriented ethanol and corn-trade policies can reduce climate-induced US corn price volatility ENVIRONMENTAL RESEARCH LETTERS Verma, M., Hertel, T., Diffenbaugh, N. 2014; 9 (6)

  View details for DOI 10.1088/1748-9326/9/6/064028

  View details for Web of Science ID 000341825200030

• Projected changes in African easterly wave intensity and track in response to greenhouse forcing PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Skinner, C. B., Diffenbaugh, N. S. 2014; 111 (19): 6882-6887

  Abstract

  Synoptic-scale African easterly waves (AEWs) impact weather throughout the greater Atlantic basin. Over the African continent, AEWs are instrumental in initiating and organizing precipitation in the drought-vulnerable Sahel region. AEWs also serve as the precursors to the most intense Atlantic hurricanes, and contribute to the global transport of Saharan dust. Given the relevance of AEWs for the climate of the greater Atlantic basin, we investigate the response of AEWs to increasing greenhouse gas concentrations. Using an ensemble of general circulation models, we find a robust increase in the strength of the winds associated with AEWs along the Intertropical Front in West Africa by the late 21st century of the representative concentration pathway 8.5. AEW energy increases directly due to an increase in baroclinicity associated with an enhanced meridional temperature gradient between the Sahara and Guinea Coast. Further, the pattern of low-level warming supports AEW development by enhancing monsoon flow, resulting in greater convergence and uplift along the Intertropical Front. These changes in energetics result in robust increases in the occurrence of conditions that currently produce AEWs. Given relationships observed in the current climate, such changes in the location of AEW tracks and the magnitude of AEW winds carry implications for the relationship between AEWs and precipitation in the Sahel, the mobilization of Saharan dust, and the likelihood of cyclogenesis in the Atlantic. Our results therefore suggest that changes in AEW characteristics could play a critical role in shaping the response of Atlantic basin climate to future increases in greenhouse gas concentrations.

  View details for DOI 10.1073/pnas.1319597111

  View details for Web of Science ID 000335798000042

  View details for PubMedID 24778244

  View details for PubMedCentralID PMC4024927

• Transient twenty-first century changes in daily-scale temperature extremes in the United States CLIMATE DYNAMICS Scherer, M., Diffenbaugh, N. S. 2014; 42 (5-6): 1383-1404

  View details for DOI 10.1007/s00382-013-1829-2

  View details for Web of Science ID 000331969800018

• Nonhydrostatic nested climate modeling: A case study of the 2010 summer season over the western United States JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Lebassi-Habtezion, B., Diffenbaugh, N. S. 2013; 118 (19): 10944-10962

  View details for Web of Science ID 000330266700001

• Near-term acceleration of hydroclimatic change in the western US JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Ashfaq, M., Ghosh, S., Kao, S., Bowling, L. C., Mote, P., Touma, D., Rauscher, S. A., Diffenbaugh, N. S. 2013; 118 (19): 10676-10693

  View details for Web of Science ID 000330266700016

• Robust increases in severe thunderstorm environments in response to greenhouse forcing PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Diffenbaugh, N. S., Scherer, M., Trapp, R. J. 2013; 110 (41): 16361-16366

  Abstract

  Although severe thunderstorms are one of the primary causes of catastrophic loss in the United States, their response to elevated greenhouse forcing has remained a prominent source of uncertainty for climate change impacts assessment. We find that the Coupled Model Intercomparison Project, Phase 5, global climate model ensemble indicates robust increases in the occurrence of severe thunderstorm environments over the eastern United States in response to further global warming. For spring and autumn, these robust increases emerge before mean global warming of 2 °C above the preindustrial baseline. We also find that days with high convective available potential energy (CAPE) and strong low-level wind shear increase in occurrence, suggesting an increasing likelihood of atmospheric conditions that contribute to the most severe events, including tornadoes. In contrast, whereas expected decreases in mean wind shear have been used to argue for a negative influence of global warming on severe thunderstorms, we find that decreases in shear are in fact concentrated in days with low CAPE and therefore do not decrease the total occurrence of severe environments. Further, we find that the shift toward high CAPE is most concentrated in days with low convective inhibition, increasing the occurrence of high-CAPE/low-convective inhibition days. The fact that the projected increases in severe environments are robust across a suite of climate models, emerge in response to relatively moderate global warming, and result from robust physical changes suggests that continued increases in greenhouse forcing are likely to increase severe thunderstorm occurrence, thereby increasing the risk of thunderstorm-related damage.

  View details for DOI 10.1073/pnas.1307758110

  View details for Web of Science ID 000325395600031

  View details for PubMedID 24062439

  View details for PubMedCentralID PMC3799355

• EXPLAINING EXTREME EVENTS OF 2012 FROM A CLIMATE PERSPECTIVE BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Peterson, T. C., Hoerling, M. P., Stott, P. A., Herring, S. C., Alexander, L. V., Allen, M. R., Anel, J., Barriopedro, D., Black, M. T., Carey-Smith, T., Castillo, R., Cattiaux, J., Chen, X., Chen, X., Chevallier, M., Christidis, N., Ciavarella, A., de Vries, H., Dean, S. M., Deans, K., Diffenbaugh, N. S., Doblas-Reyes, F., Donat, M. G., Dong, B., Eilerts, G., Funk, C., Galu, G., Garcia-Herrera, R., Germe, A., Gill, S., Gimeno, L., Guemas, V., Herring, S. C., Hoell, A., Hoerling, M. P., Huntingford, C., Husak, G., Imada, Y., Ishii, M., Karoly, D. J., Kimoto, M., King, A. D., Knutson, T. R., Lewis, S. C., Lin, R., Lyon, B., Massey, N., Mazza, E., Michaelsen, J., Michaelsen, J., Mori, M., Mote, P. W., Nieto, R., Otto, F. E., Park, J., Perkins, S. E., Peterson, T. C., Rosier, S., Rowland, J., Rupp, D. E., Salas y Melia, D., Scherer, M., Shiogama, H., Shukla, S., Song, F., Sparrow, S., Scott, P. A., Sutton, R., Sweet, W., Tett, S. F., Trigo, R. M., van Oldenborgh, G. J., van Westrhenen, R., Verdin, J., Watanabe, M., Wittenberg, A. T., Woollings, T., Yiou, P., Zeng, F., Zervas, C., Zhang, R., Zhou, T. 2013; 94 (9)

  View details for DOI 10.1175/BAMS-D-13-00085.1

  View details for Web of Science ID 000325135100001

• Changes in Ecologically Critical Terrestrial Climate Conditions SCIENCE Diffenbaugh, N. S., Field, C. B. 2013; 341 (6145): 486-492

  Abstract

  Terrestrial ecosystems have encountered substantial warming over the past century, with temperatures increasing about twice as rapidly over land as over the oceans. Here, we review the likelihood of continued changes in terrestrial climate, including analyses of the Coupled Model Intercomparison Project global climate model ensemble. Inertia toward continued emissions creates potential 21st-century global warming that is comparable in magnitude to that of the largest global changes in the past 65 million years but is orders of magnitude more rapid. The rate of warming implies a velocity of climate change and required range shifts of up to several kilometers per year, raising the prospect of daunting challenges for ecosystems, especially in the context of extensive land use and degradation, changes in frequency and severity of extreme events, and interactions with other stresses.

  View details for DOI 10.1126/science.1237123

  View details for Web of Science ID 000322586700039

  View details for PubMedID 23908225

• Precipitation extremes over the continental United States in a transient, high-resolution, ensemble climate model experiment JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Singh, D., Tsiang, M., Rajaratnam, B., Diffenbaugh, N. S. 2013; 118 (13): 7063-7086

  View details for DOI 10.1002/jgrd.50543

  View details for Web of Science ID 000322192200013

• MONITORING AND UNDERSTANDING CHANGES IN HEAT WAVES, COLD WAVES, FLOODS, AND DROUGHTS IN THE UNITED STATES: State of Knowledge BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Peterson, T. C., Heim, R. R., Hirsch, R., Kaiser, D. P., Brooks, H., Diffenbaugh, N. S., Dole, R. M., Giovannettone, J. P., Guirguis, K., Karl, T. R., Katz, R. W., Kunkel, K., Lettenmaier, D., McCabe, G. J., Paciorek, C. J., Ryberg, K. R., Schubert, S., Silva, V. B., Stewart, B. C., Vecchia, A. V., Villarini, G., Vose, R. S., Walsh, J., Wehner, M., Wolock, D., Wolter, K., Woodhouse, C. A., Wuebbles, D. 2013; 94 (6): 821-834

  View details for DOI 10.1175/BAMS-D-12-00066.1

  View details for Web of Science ID 000321256100005

• The contribution of African easterly waves to monsoon precipitation in the CMIP3 ensemble JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Skinner, C. B., Diffenbaugh, N. S. 2013; 118 (9): 3590-3609

  View details for DOI 10.1002/jgrd.50363

  View details for Web of Science ID 000319744700011

• Response of snow-dependent hydrologic extremes to continued global warming NATURE CLIMATE CHANGE Diffenbaugh, N. S., Scherer, M., Ashfaq, M. 2013; 3 (4): 379-384

  View details for DOI 10.1038/NCLIMATE1732

  View details for Web of Science ID 000319400400020

• Response of snow-dependent hydrologic extremes to continued global warming. Nature climate change Diffenbaugh, N. S., Scherer, M., Ashfaq, M. 2013; 3: 379-384

  Abstract

  Snow accumulation is critical for water availability in the northern hemisphere 1,2, raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions 1,3. Although regional hydrologic changes have been observed (e.g., 1,3-5), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate change impacts 3,6,7. We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the northern hemisphere, with areas of western North America, northeastern Europe, and the Greater Himalaya showing the strongest emergence during the near-term decades and at 2°C global warming. The occurrence of extremely low snow years becomes widespread by the late-21st century, as do the occurrence of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the northern hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2°C above the pre-industrial baseline.

  View details for DOI 10.1038/nclimate1732

  View details for PubMedID 24015153

  View details for PubMedCentralID PMC3760585

• Using climate impacts indicators to evaluate climate model ensembles: temperature suitability of premium winegrape cultivation in the United States CLIMATE DYNAMICS Diffenbaugh, N. S., Scherer, M. 2013; 40 (3-4): 709-729

  View details for DOI 10.1007/s00382-012-1377-1

  View details for Web of Science ID 000314292200011

• Human well-being, the global emissions debt, and climate change commitment SUSTAINABILITY SCIENCE Diffenbaugh, N. S. 2013; 8 (1): 135-141

  View details for DOI 10.1007/s11625-012-0174-4

  View details for Web of Science ID 000313029000011

• Near-term acceleration of hydroclimatic change in the western U.S. Journal of Geophysical Research Atmospheres Ashfaq, M., Ghosh, S., Kao, S., Bowling, L., Mote, P., Touma, D., Rauscher, S., Diffenbaugh, N. 2013; 118: 10,676–10,693

  View details for DOI 10.1002/jgrd.50816

• Nonhydrostatic nested climate modeling: A case study of the 2010 summer season over the western United States Journal of Geophysical Research Atmospheres Lebassi-Habtezion, B., Diffenbaugh, N. S. 2013; 118: 10,944–10,962

  View details for DOI 10.1002/jgrd.50773

• Transient 21st century changes in daily-scale temperature extremes in the United States Climate Dynamics Scherer, M., Diffenbaugh, N. S. 2013: 1829
• Effects of U.S. Tax Policy on Greenhouse Gas Emissions Norhaus, W. D., Cropoper, M. L., de la Chesnaye, F., Diffenbaugh, N., Hawkins, D. G., Mann, R. F., Murray, B. C., Reilly, J. M., Shindell, D., Toder, E., Williams, R. C., Wolfram, C. The National Academies Press. 2013
• Response of air stagnation frequency to anthropogenically enhanced radiative forcing ENVIRONMENTAL RESEARCH LETTERS Horton, D. E., Harshvardhan, Diffenbaugh, N. S. 2012; 7 (4)

  View details for DOI 10.1088/1748-9326/7/4/044034

  View details for Web of Science ID 000312696400038

• Climate change hotspots in the CMIP5 global climate model ensemble CLIMATIC CHANGE Diffenbaugh, N. S., Giorgi, F. 2012; 114 (3-4): 813-822

  View details for DOI 10.1007/s10584-012-0570-x

  View details for Web of Science ID 000308246300022

• Out of the Tropics: The Pacific, Great Basin Lakes, and Late Pleistocene Water Cycle in the Western United States SCIENCE Lyle, M., Heusser, L., Ravelo, C., Yamamoto, M., Barron, J., Diffenbaugh, N. S., Herbert, T., Andreasen, D. 2012; 337 (6102): 1629-1633

  Abstract

  The water cycle in the western United States changed dramatically over glacial cycles. In the past 20,000 years, higher precipitation caused desert lakes to form which have since dried out. Higher glacial precipitation has been hypothesized to result from a southward shift of Pacific winter storm tracks. We compared Pacific Ocean data to lake levels from the interior west and found that Great Basin lake high stands are older than coastal wet periods at the same latitude. Westerly storms were not the source of high precipitation. Instead, air masses from the tropical Pacific were transported northward, bringing more precipitation into the Great Basin when coastal California was still dry. The changing climate during the deglaciation altered precipitation source regions and strongly affected the regional water cycle.

  View details for DOI 10.1126/science.1218390

  View details for Web of Science ID 000309215400038

  View details for PubMedID 23019644

• Agriculture and Trade Opportunities for Tanzania: Past Volatility and Future Climate Change REVIEW OF DEVELOPMENT ECONOMICS Ahmed, S. A., Diffenbaugh, N. S., Hertel, T. W., Martin, W. J. 2012; 16 (3): 429-447

  View details for DOI 10.1111/j.1467-9361.2012.00672.x

  View details for Web of Science ID 000306362000005

• Response of corn markets to climate volatility under alternative energy futures NATURE CLIMATE CHANGE Diffenbaugh, N. S., Hertel, T. W., Scherer, M., Verma, M. 2012; 2 (7): 514-518

  Abstract

  Recent price spikes(1,2) have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades(3,4). However, commodity price volatility is also influenced by other factors(5,6), which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change.

  View details for DOI 10.1038/NCLIMATE1491

  View details for Web of Science ID 000306249500015

  View details for PubMedCentralID PMC3519383

• Response of corn markets to climate volatility under alternative energy futures. Nature climate change Diffenbaugh, N. S., Hertel, T. W., Scherer, M., Verma, M. 2012; 2: 514-518

  Abstract

  Recent price spikes(1,2) have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades(3,4). However, commodity price volatility is also influenced by other factors(5,6), which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change.

  View details for DOI 10.1038/nclimate1491

  View details for PubMedID 23243468

  View details for PubMedCentralID PMC3519383

• Amplification of wet and dry month occurrence over tropical land regions in response to global warming JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Lintner, B. R., Biasutti, M., Diffenbaugh, N. S., Lee, J., Niznik, M. J., Findell, K. L. 2012; 117

  View details for DOI 10.1029/2012JD017499

  View details for Web of Science ID 000305147200005

• Influence of Twenty-First-Century Atmospheric and Sea Surface Temperature Forcing on West African Climate JOURNAL OF CLIMATE Skinner, C. B., Ashfaq, M., Diffenbaugh, N. S. 2012; 25 (2): 527-542

  View details for DOI 10.1175/2011JCLI4183.1

  View details for Web of Science ID 000299649600007

• Climate change hotspots in the CMIP5 global climate model ensemble. Climatic change Diffenbaugh, N. S., Giorgi, F. 2012; 114 (3-4): 813-822

  Abstract

  We use a statistical metric of multi-dimensional climate change to quantify the emergence of global climate change hotspots in the CMIP5 climate model ensemble. Our hotspot metric extends previous work through the inclusion of extreme seasonal temperature and precipitation, which exert critical influence on climate change impacts. The results identify areas of the Amazon, the Sahel and tropical West Africa, Indonesia, and the Tibetan Plateau as persistent regional climate change hotspots throughout the 21st century of the RCP8.5 and RCP4.5 forcing pathways. In addition, areas of southern Africa, the Mediterranean, the Arctic, and Central America/western North America also emerge as prominent regional climate change hotspots in response to intermediate and high levels of forcing. Comparisons of different periods of the two forcing pathways suggest that the pattern of aggregate change is fairly robust to the level of global warming below approximately 2°C of global warming (relative to the late-20th-century baseline), but not at the higher levels of global warming that occur in the late-21st-century period of the RCP8.5 pathway, with areas of southern Africa, the Mediterranean, and the Arctic exhibiting particular intensification of relative aggregate climate change in response to high levels of forcing. Although specific impacts will clearly be shaped by the interaction of climate change with human and biological vulnerabilities, our identification of climate change hotspots can help to inform mitigation and adaptation decisions by quantifying the rate, magnitude and causes of the aggregate climate response in different parts of the world.

  View details for DOI 10.1007/s10584-012-0570-x

  View details for PubMedID 24014154

  View details for PubMedCentralID PMC3765072

• Response of air stagnation frequency to anthropogenically enhanced radiative forcing. Environmental research letters : ERL [Web site] Horton, D. E., Diffenbaugh, N. S. 2012; 7 (4)

  Abstract

  Stagnant atmospheric conditions can lead to hazardous air quality by allowing ozone and particulate matter to accumulate and persist in the near-surface environment. By changing atmospheric circulation and precipitation patterns, global warming could alter the meteorological factors that regulate air stagnation frequency. We analyze the response of the National Climatic Data Center (NCDC) Air Stagnation Index (ASI) to anthropogenically enhanced radiative forcing using global climate model projections of late-21(st) century climate change (SRES A1B scenario). Our results indicate that the atmospheric conditions over the highly populated, highly industrialized regions of the eastern United States, Mediterranean Europe, and eastern China are particularly sensitive to global warming, with the occurrence of stagnant conditions projected to increase 12-to-25% relative to late-20(th) century stagnation frequencies (3-18+ days/year). Changes in the position/strength of the polar jet, in the occurrence of light surface winds, and in the number of precipitation-free days all contribute to more frequent late-21(st) century air mass stagnation over these high-population regions. In addition, we find substantial inter-model spread in the simulated response of stagnation conditions over some regions using either native or bias corrected global climate model simulations, suggesting that changes in the atmospheric circulation and/or the distribution of precipitation represent important sources of uncertainty in the response of air quality to global warming.

  View details for DOI 10.1088/1748-9326/7/4/044034

  View details for PubMedID 23284587

  View details for PubMedCentralID PMC3532903

• Transient regional climate change: analysis of the summer climate response in a high-resolution, century-scale, ensemble experiment over the continental United States. Journal of geophysical research Diffenbaugh, N. S., Ashfaq, M., Scherer, M. 2011; 116 (D24)

  Abstract

  Integrating the potential for climate change impacts into policy and planning decisions requires quantification of the emergence of sub-regional climate changes that could occur in response to transient changes in global radiative forcing. Here we report results from a high-resolution, century-scale, ensemble simulation of climate in the United States, forced by atmospheric constituent concentrations from the Special Report on Emissions Scenarios (SRES) A1B scenario. We find that 21st century summer warming permanently emerges beyond the baseline decadal-scale variability prior to 2020 over most areas of the continental U.S. Permanent emergence beyond the baseline annual-scale variability shows much greater spatial heterogeneity, with emergence occurring prior to 2030 over areas of the southwestern U.S., but not prior to the end of the 21st century over much of the southcentral and southeastern U.S. The pattern of emergence of robust summer warming contrasts with the pattern of summer warming magnitude, which is greatest over the central U.S. and smallest over the western U.S. In addition to stronger warming, the central U.S. also exhibits stronger coupling of changes in surface air temperature, precipitation, and moisture and energy fluxes, along with changes in atmospheric circulation towards increased anticylonic anomalies in the mid-troposphere and a poleward shift in the mid-latitude jet aloft. However, as a fraction of the baseline variability, the transient warming over the central U.S. is smaller than the warming over the southwestern or northeastern U.S., delaying the emergence of the warming signal over the central U.S. Our comparisons with observations and the Coupled Model Intercomparison Project Phase 3 (CMIP3) ensemble of global climate model experiments suggest that near-term global warming is likely to cause robust sub-regional-scale warming over areas that exhibit relatively little baseline variability. In contrast, where there is greater variability in the baseline climate dynamics, there can be greater variability in the response to elevated greenhouse forcing, decreasing the robustness of the transient warming signal.

  View details for DOI 10.1029/2011JD016458

  View details for PubMedID 24307747

  View details for PubMedCentralID PMC3845530

• Transient regional climate change: Analysis of the summer climate response in a high-resolution, century-scale ensemble experiment over the continental United States JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Diffenbaugh, N. S., Ashfaq, M., Scherer, M. 2011; 116

  View details for DOI 10.1029/2011JD016458

  View details for Web of Science ID 000298495700004

• Higher Hydroclimatic Intensity with Global Warming JOURNAL OF CLIMATE Giorgi, F., Im, E., Coppola, E., Diffenbaugh, N. S., Gao, X. J., Mariotti, L., Shi, Y. 2011; 24 (20): 5309-5324

  View details for DOI 10.1175/2011JCLI3979.1

  View details for Web of Science ID 000296476700008

• Regional climate of hazardous convective weather through high-resolution dynamical downscaling CLIMATE DYNAMICS Trapp, R. J., Robinson, E. D., Baldwin, M. E., Diffenbaugh, N. S., Schwedler, B. R. 2011; 37 (3-4): 677-688

  View details for DOI 10.1007/s00382-010-0826-y

  View details for Web of Science ID 000293403500016

• Observational and model evidence of global emergence of permanent, unprecedented heat in the 20(th) and 21(st) centuries. Climatic change Diffenbaugh, N. S., Scherer, M. 2011; 107 (3-4): 615-624

  Abstract

  Given the severe impacts of extreme heat on natural and human systems, we attempt to quantify the likelihood that rising greenhouse gas concentrations will result in a new, permanent heat regime in which the coolest warm-season of the 21(st) century is hotter than the hottest warm-season of the late 20(th) century. Our analyses of global climate model experiments and observational data reveal that many areas of the globe are likely to permanently move into such a climate space over the next four decades, should greenhouse gas concentrations continue to increase. In contrast to the common perception that high-latitude areas face the most accelerated response to global warming, our results demonstrate that in fact tropical areas exhibit the most immediate and robust emergence of unprecedented heat, with many tropical areas exhibiting a 50% likelihood of permanently moving into a novel seasonal heat regime in the next two decades. We also find that global climate models are able to capture the observed intensification of seasonal hot conditions, increasing confidence in the projection of imminent, permanent emergence of unprecedented heat.

  View details for DOI 10.1007/s10584-011-0112-y

  View details for PubMedID 22707810

  View details for PubMedCentralID PMC3374649

• Observational and model evidence of global emergence of permanent, unprecedented heat in the 20th and 21st centuries CLIMATIC CHANGE Diffenbaugh, N. S., Scherer, M. 2011; 107 (3-4): 615-624

  View details for DOI 10.1007/s10584-011-0112-y

  View details for Web of Science ID 000293288400020

• Climate adaptation wedges: a case study of premium wine in the western United States ENVIRONMENTAL RESEARCH LETTERS Diffenbaugh, N. S., White, M. A., Jones, G. V., Ashfaq, M. 2011; 6 (2)

  View details for DOI 10.1088/1748-9326/6/2/024024

  View details for Web of Science ID 000295326800024

• Influence of SST biases on future climate change projections CLIMATE DYNAMICS Ashfaq, M., Skinner, C. B., Diffenbaugh, N. S. 2011; 36 (7-8): 1303-1319

  View details for DOI 10.1007/s00382-010-0875-2

  View details for Web of Science ID 000289105300006

• Biophysical considerations in forestry for climate protection FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Anderson, R. G., Canadell, J. G., Randerson, J. T., Jackson, R. B., Hungate, B. A., Baldocchi, D. D., Ban-Weiss, G. A., Bonan, G. B., Caldeira, K., Cao, L., Diffenbaugh, N. S., Gurney, K. R., Kueppers, L. M., Law, B. E., Luyssaert, S., O'Halloran, T. L. 2011; 9 (3): 174-182

  View details for DOI 10.1890/090179

  View details for Web of Science ID 000289377800019

• Climate volatility and poverty vulnerability in Tanzania GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS Ahmed, S. A., Diffenbaugh, N. S., Hertel, T. W., Lobell, D. B., Ramankutty, N., Rios, A. R., Rowhani, P. 2011; 21 (1): 46-55

  View details for DOI 10.1016/j.gloenvcha.2010.10.003

  View details for Web of Science ID 000293811200007

• Implications of the permanent El Nino teleconnection "blueprint" for past global and North American hydroclimatology CLIMATE OF THE PAST Goldner, A., Huber, M., Diffenbaugh, N., Caballero, R. 2011; 7 (3): 723-743

  View details for DOI 10.5194/cp-7-723-2011

  View details for Web of Science ID 000295356800004

• Pleistocene water cycle and eastern boundary current processes along the California continental margin PALEOCEANOGRAPHY Lyle, M., Heusser, L., Ravelo, C., Andreasen, D., Lyle, A. O., Diffenbaugh, N. 2010; 25

  View details for DOI 10.1029/2009PA001836

  View details for Web of Science ID 000283950900001

• Temperature and equivalent temperature over the United States (1979-2005) INTERNATIONAL JOURNAL OF CLIMATOLOGY Fall, S., Diffenbaugh, N. S., Niyogi, D., Pielke, R. A., Rochon, G. 2010; 30 (13): 2045-2054

  View details for DOI 10.1002/joc.2094

  View details for Web of Science ID 000284211300013

• Intensification of hot extremes in the United States GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S., Ashfaq, M. 2010; 37

  View details for DOI 10.1029/2010GL043888

  View details for Web of Science ID 000280718100001

• Influence of climate model biases and daily-scale temperature and precipitation events on hydrological impacts assessment: A case study of the United States JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Ashfaq, M., Bowling, L. C., Cherkauer, K., Pal, J. S., Diffenbaugh, N. S. 2010; 115

  View details for DOI 10.1029/2009JD012965

  View details for Web of Science ID 000280587000006

• Rapid, time-transgressive, and variable responses to early Holocene midcontinental drying in North America GEOLOGY Williams, J. W., Shuman, B., Bartlein, P. J., Diffenbaugh, N. S., Webb, T. 2010; 38 (2): 135-138

  View details for DOI 10.1130/G30413.1

  View details for Web of Science ID 000274209100010

• Rapid, time-transgressive, and variable responses to end-Pleistocene/early Holocene midcontinental drying in North America Geology Williams, J. W., Shuman, B. N., Bartlein, P. J., Diffenbaugh, N. S., Webb, T. 2010; 38: 135-138
• Geophysical Research Letters: New Policies Improve Top-Cited Geosciences Journal Eos Transactions American Geophysical Union Calais, E., Diffenbaugh, N., D'Odorico, P., Harris, R., Knorr, W., Lavraud, B., Mueller, A., Peterson, W., Rignot, E., Srokosz, M., Strutton, P., Tyndall, G., Wysession, M., Williams, P. 2010; 91: 337

  View details for DOI 10.1029/2010EO380008

• Influence of modern land cover on the climate of the United States CLIMATE DYNAMICS Diffenbaugh, N. S. 2009; 33 (7-8): 945-958

  View details for DOI 10.1007/s00382-009-0566-z

  View details for Web of Science ID 000271959900004

• Evaluation of high-resolution simulations of daily-scale temperature and precipitation over the United States CLIMATE DYNAMICS Walker, M. D., Diffenbaugh, N. S. 2009; 33 (7-8): 1131-1147

  View details for DOI 10.1007/s00382-009-0603-y

  View details for Web of Science ID 000271959900017

• Land surface coupling in regional climate simulations of the West African monsoon CLIMATE DYNAMICS Steiner, A. L., Pal, J. S., Rauscher, S. A., Bell, J. L., Diffenbaugh, N. S., Boone, A., Sloan, L. C., Giorgi, F. 2009; 33 (6): 869-892

  View details for DOI 10.1007/s00382-009-0543-6

  View details for Web of Science ID 000270684100010

• Climate volatility deepens poverty vulnerability in developing countries ENVIRONMENTAL RESEARCH LETTERS Ahmed, S. A., Diffenbaugh, N. S., Hertel, T. W. 2009; 4 (3)

  View details for DOI 10.1088/1748-9326/4/3/034004

  View details for Web of Science ID 000270659300008

• Suppression of south Asian summer monsoon precipitation in the 21st century GEOPHYSICAL RESEARCH LETTERS Ashfaq, M., Shi, Y., Tung, W., Trapp, R. J., Gao, X., Pal, J. S., Diffenbaugh, N. S. 2009; 36 (1)

  View details for DOI 10.1029/2008GL036500

  View details for Web of Science ID 000262168900007

• Transient response of severe thunderstorm forcing to elevated greenhouse gas concentrations GEOPHYSICAL RESEARCH LETTERS Trapp, R. J., Diffenbaugh, N. S., Gluhovsky, A. 2009; 36 (1)

  View details for DOI 10.1029/2008GL036203

  View details for Web of Science ID 000262168900004

• Land surface coupling in regional climate simulations of the west African monsoon Climate Dynamics Steiner, A. L., Pal, J. S., Rauscher, S. A., Bell, J. L., Diffenbaugh, N. S., Giorgi, F., Sloan, L. C. 2009

  View details for DOI 10.1007/s00382-009-0543-6

• Climate variability, climate change, and wine production in the western United States Climate Change in Western North America: Evidence and Environmental Effects White, M. A., Jones, G. V., Diffenbaugh, N. S. edited by Wagner, F. H. University of Utah Press. 2009
• Suppression of South Asian summer monsoon precipitation in the 21st century Geophysical Research Letters Ashfaq, M., Shi, Y., Tung, W. W., Trapp, R. J., Gao, X., Pal, J. S., Diffenbaugh, N. S. 2009; 36

  View details for DOI 10.1029/2008GL036500

• Evaluation of high-resolution simulations of daily-scale temperature and precipitation over the United States Climate Dynamics Walker, M. D., Diffenbaugh, N. S. 2009

  View details for DOI 10.1007/s00382-009-0603-y

• Influence of modern land cover on the climate of the United States Climate Dynamics Diffenbaugh, N. S. 2009

  View details for DOI 10.1007/s00382-009-0566-z

• Transient response of severe thunderstorm forcing to elevated greenhouse gas concentrations Geophysical Research Letters Trapp, R. J., Diffenbaugh, N. S., Gluhovsky, A. 2009; 36 (1)

  View details for DOI 10.1029/2008GL036203

• Protecting climate with forests ENVIRONMENTAL RESEARCH LETTERS Jackson, R. B., Randerson, J. T., Canadell, J. G., Anderson, R. G., Avissar, R., Baldocchi, D. D., Bonan, G. B., Caldeira, K., Diffenbaugh, N. S., Field, C. B., Hungate, B. A., Jobbagy, E. G., Kueppers, L. M., Nosetto, M. D., Pataki, D. E. 2008; 3 (4)

  View details for DOI 10.1088/1748-9326/3/4/044006

  View details for Web of Science ID 000265878400006

• Global warming presents new challenges for maize pest management ENVIRONMENTAL RESEARCH LETTERS Diffenbaugh, N. S., Krupke, C. H., White, M. A., Alexander, C. E. 2008; 3 (4)

  View details for DOI 10.1088/1748-9326/3/4/044007

  View details for Web of Science ID 000265878400007

• Extension and Intensification of the Meso-American mid-summer drought in the twenty-first century CLIMATE DYNAMICS Rauscher, S. A., Giorgi, F., Diffenbaugh, N. S., Seth, A. 2008; 31 (5): 551-571

  View details for DOI 10.1007/s00382-007-0359-1

  View details for Web of Science ID 000258672400004

• Climate change hotspots in the United States GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S., Giorgi, F., Pal, J. S. 2008; 35 (16)

  View details for DOI 10.1029/2008GL035075

  View details for Web of Science ID 000258820600007

• Future changes in snowmelt-driven runoff timing over the western US GEOPHYSICAL RESEARCH LETTERS Rauscher, S. A., Pal, J. S., Diffenbaugh, N. S., Benedetti, M. M. 2008; 35 (16)

  View details for DOI 10.1029/2008GL034424

  View details for Web of Science ID 000258645200002

• Developing regional climate change scenarios for use in assessment of effects on human health and disease CLIMATE RESEARCH Giorgi, F., Diffenbaugh, N. 2008; 36 (2): 141-151

  View details for DOI 10.3354/cr00728

  View details for Web of Science ID 000256188800006

• Hydrological variability and change Abrupt Climate Change. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research Cook, E. R., Bartlein, P. J., Diffenbaugh, N., Seager, R., Shuman, B. N., Webb, R. S., Williams, J. W., Woodhouse, C. U.S. Geological Survey, Reston, VA. 2008: 143–257
• Extension and intensification of the Meso-American mid-summer drought in the 21st century Climate Dynamics Rauscher, S. A., Giorgi, F., Diffenbaugh, N. S., Seth, A. 2008

  View details for DOI 10.1007/s00382-007-0359-1

• Developing regional climate change scenarios for use in assessment of effects on human health and disease Climate Research Giorgi, F., Diffenbaugh, N. 2008; 36: 141-151
• Future changes in runoff timing over the western United States Geophysical Research Letters Rauscher, S. A., Pal, J. S., Diffenbaugh, N. S., Benedetti, M. 2008; 35

  View details for DOI 10.1029/2008GL034424

• The regional climate change hyper-matrix framework Eos Giorgi, F., Diffenbaugh, N. S., Gao, X. J., Coppola, E., Dash, S. K., Frumento, O., Sanda, I. S., Rauscher, S., Remedio, A., Steiner, A., Sylla, B., Zakey, A. 2008; 89: 445-446
• Does global warming influence tornado activity? Eos Diffenbaugh, N. S., Trapp, R. J., Brooks, H. E. 2008; 89: 553-554
• Climate change hotspots in the United States Geophysical Research Letters Diffenbaugh, N. S., Giorgi, F., Pal, J. S. 2008; 35

  View details for DOI 10.1029/2008GL035075

• Global warming presents new challenges for maize pest management Environmental Research Letters Diffenbaugh, N. S., Krupke, C. H., White, M. A., Alexander, C. E. 2008

  View details for DOI 10.1088/1748-9326/3/4/044007

• Indicators of 21st century socioclimatic exposure PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Diffenbaugh, N. S., Giorgi, F., Raymond, L., Bi, X. 2007; 104 (51): 20195-20198

  Abstract

  Policies that attempt to curb greenhouse gas emissions, allocate emissions rights, or distribute compensation to those most damaged by climate change must explicitly incorporate the international heterogeneity of the climate change threat. To capture the distinct susceptibilities associated with lack of infrastructure, potential property loss, and gross human exposure, we develop an integration of climate change projections and poverty, wealth, and population metrics. Our analysis shows that most nations of the world are threatened by the interaction of regional climatic changes with one or more relevant socioeconomic factors. Nations that have the highest levels of poverty, wealth, and population face greater relative exposure in those dimensions. However, for each of those socioeconomic indicators, spatial heterogeneity in projected climate change determines the overall international pattern of socioclimatic exposure. Our synthesis provides a critical missing piece to the climate change debate and should facilitate the formulation of climate policies that account for international variations in the threat of climate change across a range of socioeconomic dimensions.

  View details for DOI 10.1073/pnas.0706680105

  View details for Web of Science ID 000251885000010

  View details for PubMedID 18077324

• Changes in severe thunderstorm environment frequency during the 21st century caused by anthropogenically enhanced global radiative forcing PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Trapp, R. J., Diffenbaugh, N. S., Brooks, H. E., Baldwin, M. E., Robinson, E. D., Pal, J. S. 2007; 104 (50): 19719-19723

  View details for DOI 10.1073/pnas.0705494104

  View details for Web of Science ID 000251752200015

• Telescoping, multimodel approaches to evaluate extreme convective weather under future climates JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Trapp, R. J., Halvorson, B. A., Diffenbaugh, N. S. 2007; 112 (D20)

  View details for DOI 10.1029/2006JD008345

  View details for Web of Science ID 000259184600006

• Regional climate modeling for the developing world - The ICTP RegCM3 and RegCNET BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Pal, J. S., Giorgi, F., Bi, X., Elguindi, N., Solmon, F., Gao, X., Rauscher, S. A., Francisco, R., Zakey, A., Winter, J., Ashfaq, M., Syed, F. S., Bell, J. L., Diffenbaugh, N. S., Karmacharya, J., Konare, A., Martinez, D., da Rocha, R. P., Sloan, L. C., Steiner, A. L. 2007; 88 (9): 1395-?

  View details for DOI 10.1175/BAMS-88-9-1395

  View details for Web of Science ID 000250166400005

• Response of California Current forcing to mid-Holocene insolation and sea surface temperatures PALEOCEANOGRAPHY Diffenbaugh, N. S., Ashfaq, M. 2007; 22 (3)

  View details for DOI 10.1029/2006PA001382

  View details for Web of Science ID 000247886100001

• Heat stress intensification in the Mediterranean climate change hotspot GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S., Pal, J. S., Giorgi, F., Gao, X. 2007; 34 (11)

  View details for DOI 10.1029/2007GL030000

  View details for Web of Science ID 000247368800003

• Changes in severe thunderstorm environment frequency in the 21st century due to anthropogenically enhanced global radiative forcing Proceedings of the National Academy of Sciences Trapp, R. J., Diffenbaugh, N. S., Brooks, H. E., Baldwin, M., Robinson, E. D., Pal, J. S. 2007; 104: 19719-19723
• Diffenbaugh Receives 2006 James R. Holton Junior Scientist Award Eos Transactions American Geophysical Union Harshvardhan, G., Diffenbaugh, N. 2007; 111: 111

  View details for DOI 10.1029/2007EO090011

• Heat stress intensification in the Mediterranean climate change hotspot Geophysical Research Letters Diffenbaugh, N. S., Pal, J. S., Giorgi, F., Gao, X. 2007; 34

  View details for DOI 10.1029/2007GL030000

• Response of California Current forcing to mid-Holocene changes in insolation and sea surface temperature Paleoceanography Diffenbaugh , N. S., Ashfaq, M. 2007; 22

  View details for DOI 10.1029/2006PA001382

• Regional climate modeling for the developing world: The ICTP RegCM3 and RegCNET Bulletin of the American Meteorological Society Pal, J. S., Giorgi, F., Bi, X., Elguindi, N., Solmon, F., Gao, X., Rauscher, S. A., Francisco, R., Zakey, A., Winter, J., Ashfaq, M., Syed, F. S., , Bell, J. L.,, J. L., Diffenbaugh, N. S., , N. S., Karmacharya, J., , J., Konare, A., , A., Martinez, D., , D., da Rocha, R.P., , R. P., Sloan, L.C., , L. C., Steiner, A., A. 2007; 88: 1395-1409
• Telescoping, multi-model approaches to evaluate extreme convective weather under future climates Journal of Geophysical Research-Atmospheres Trapp, R. J., Halvorson, B. A., Diffenbaugh, N. S. 2007; 112

  View details for DOI 10.1029/2006JD008345

• Indicators of 21st century socioclimatic exposure Proceedings of the National Academy of Sciences Diffenbaugh, N. S., Giorgi, F., Raymond, L., Bi, X. 2007; 104: 20195-20198
• Summer aridity in the United States: Response to mid-Holocene changes in insolation and sea surface temperature GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S., Ashfaq, M., Shuman, B., Williams, J. W., Bartlein, P. J. 2006; 33 (22)

  View details for DOI 10.1029/2006GL028012

  View details for Web of Science ID 000242739000006

• Extreme heat reduces and shifts United States premium wine production in the 21st century PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA White, M. A., Diffenbaugh, N. S., Jones, G. V., Pal, J. S., Giorgi, F. 2006; 103 (30): 11217-11222

  Abstract

  Premium wine production is limited to regions climatically conducive to growing grapes with balanced composition and varietal typicity. Three central climatic conditions are required: (i) adequate heat accumulation; (ii) low risk of severe frost damage; and (iii) the absence of extreme heat. Although wine production is possible in an extensive climatic range, the highest-quality wines require a delicate balance among these three conditions. Although historical and projected average temperature changes are known to influence global wine quality, the potential future response of wine-producing regions to spatially heterogeneous changes in extreme events is largely unknown. Here, by using a high-resolution regional climate model forced by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios A2 greenhouse gas emission scenario, we estimate that potential premium winegrape production area in the conterminous United States could decline by up to 81% by the late 21st century. While increases in heat accumulation will shift wine production to warmer climate varieties and/or lower-quality wines, and frost constraints will be reduced, increases in the frequency of extreme hot days (>35 degrees C) in the growing season are projected to eliminate winegrape production in many areas of the United States. Furthermore, grape and wine production will likely be restricted to a narrow West Coast region and the Northwest and Northeast, areas currently facing challenges related to excess moisture. Our results not only imply large changes for the premium wine industry, but also highlight the importance of incorporating fine-scale processes and extreme events in climate-change impact studies.

  View details for DOI 10.1073/pnas.0603230103

  View details for Web of Science ID 000239353900022

  View details for PubMedID 16840557

• Simulated changes in extreme temperature and precipitation events at 6 ka PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY Diffenbaugh, N. S., Bell, J. L., Sloan, L. C. 2006; 236 (1-2): 151-168

  View details for DOI 10.1016/j.palaeo.2005.11.037

  View details for Web of Science ID 000238746200011

• Summer aridity in the United States: Response to mid-Holocene changes in insolation and sea surface temperature Geophysical Research Letters Diffenbaugh, N. S., Ashfaq, M., Shuman, B., Williams, J. W., Bartlein, P. J. 2006; 33

  View details for DOI 10.1029/2006GL028012

• Introduction to the special issue "Glacial-Interglacial Climate of the Past 160,000 Years: New Insights from Data and Models" Palaeogeography, Palaeoclimatology, Palaeoecology Diffenbaugh, N. S., Eakin, C. M., Otto-Bliesner, B. L., Zhao, M. 2006; 236: 1-4
• Extreme heat reduces and shifts United States premium wine production in the 21st century Proceedings of the National Academy of Sciences White, M. A., Diffenbaugh, N. S., Jones, G. V., Pal, J. S., Giorgi, F. 2006; 103: 11217-11222
• Simulated changes in extreme temperature and precipitation events at 6 ka Palaeogeography, Palaeoclimatology, Palaeoecology Diffenbaugh, N. S., Bell, J. L., Sloan, L. C. 2006; 236: 151-168
• Fine-scale processes regulate the response of extreme events to global climate change PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Diffenbaugh, N. S., Pal, J. S., Trapp, R. J., Giorgi, F. 2005; 102 (44): 15774-15778

  Abstract

  We find that extreme temperature and precipitation events are likely to respond substantially to anthropogenically enhanced greenhouse forcing and that fine-scale climate system modifiers are likely to play a critical role in the net response. At present, such events impact a wide variety of natural and human systems, and future changes in their frequency and/or magnitude could have dramatic ecological, economic, and sociological consequences. Our results indicate that fine-scale snow albedo effects influence the response of both hot and cold events and that peak increases in extreme hot events are amplified by surface moisture feedbacks. Likewise, we find that extreme precipitation is enhanced on the lee side of rain shadows and over coastal areas dominated by convective precipitation. We project substantial, spatially heterogeneous increases in both hot and wet events over the contiguous United States by the end of the next century, suggesting that consideration of fine-scale processes is critical for accurate assessment of local- and regional-scale vulnerability to climate change.

  View details for DOI 10.1073/pnas.0506042102

  View details for Web of Science ID 000233090900013

  View details for PubMedID 16236722

• Response of large-scale eastern boundary current forcing in the 21st century GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S. 2005; 32 (19)

  View details for DOI 10.1029/2005GL023905

  View details for Web of Science ID 000232686100005

• Sensitivity of extreme climate events to CO2-induced biophysical atmosphere-vegetation feedbacks in the western United States GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S. 2005; 32 (7)

  View details for DOI 10.1029/2004GL022184

  View details for Web of Science ID 000228376100004

• Atmosphere-land cover feedbacks alter the response of surface temperature to CO2 forcing in the western United States CLIMATE DYNAMICS Diffenbaugh, N. S. 2005; 24 (2-3): 237-251

  View details for DOI 10.1007/s00382-004-0503-0

  View details for Web of Science ID 000227945700008

• Response of large-scale eastern boundary current forcing in the 21st century Geophysical Research Letters Diffenbaugh, N. S. 2005; 32

  View details for DOI 10.1029/2005GL023905

• Sensitivity of extreme climate events to CO2-induced biophysical atmosphere-vegetation feedbacks in the western United States Geophysical Research Letters Diffenbaugh, N. S. 2005; 32

  View details for DOI 10.1029/2004GL022184

• Fine-scale processes regulate the response of extreme events to global climate change Proceedings of the National Academy of Sciences Diffenbaugh, N. S., Pal, J. S., Trapp, R. J., Giorgi, F. 2005; 102: 15774-15778
• Atmosphere-land cover feedbacks alter the response of surface temperature to CO2 forcing in the western United States Climate Dynamics Diffenbaugh, N. S. 2005; 24: 237-251
• Mid-Holocene orbital forcing of regional-scale climate: A case study of western North America using a high-resolution RCM JOURNAL OF CLIMATE Diffenbaugh, N. S., Sloan, L. C. 2004; 17 (15): 2927-2937

  View details for Web of Science ID 000223074500003

• The effects of late Quaternary climate and pCO(2) change on C-4 plant abundance in the south-central United States PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY Koch, P. L., Diffenbaugh, N. S., Hoppe, K. A. 2004; 207 (3-4): 331-357

  View details for DOI 10.1016/j.palaeo.2003.09.034

  View details for Web of Science ID 000221991000006

• Could CO2-induced land-cover feedbacks alter near-shore upwelling regimes? PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Diffenbaugh, N. S., Snyder, M. A., Sloan, L. C. 2004; 101 (1): 27-32

  Abstract

  The response of marine and terrestrial environments to global changes in atmospheric carbon dioxide (CO(2)) concentrations will likely be governed by both responses to direct environmental forcing and responses to Earth-system feedbacks induced by that forcing. It has been proposed that anthropogenic greenhouse forcing will intensify coastal upwelling in eastern boundary current regions [Bakun, A. (1990) Science 247, 198-201]. Focusing on the California Current, we show that biophysical land-cover-atmosphere feedbacks induced by CO(2) radiative forcing enhance the radiative effects of CO(2) on land-sea thermal contrast, resulting in changes in eastern boundary current total seasonal upwelling and upwelling seasonality. Specifically, relative to CO(2) radiative forcing, land-cover-atmosphere feedbacks lead to a stronger increase in peak- and late-season near-shore upwelling in the northern limb of the California Current and a stronger decrease in peak- and late-season near-shore upwelling in the southern limb. Such changes will impact both marine and terrestrial communities [Bakun, A. (1990) Science 247, 198-201; Soto, C. G. (2001) Rev. Fish Biol. Fish. 11, 181-195; and Agostini, V. N. & Bakun, A. (2002) Fish. Oceanogr. 11, 129-142], and these and other Earth-system feedbacks should be expected to play a substantial role in shaping the response of eastern boundary current regions to CO(2) radiative forcing.

  View details for DOI 10.1073/pnas.0305746101

  View details for Web of Science ID 000187937200008

  View details for PubMedID 14691256

• Mid-Holocene orbital forcing of regional-scale climate: a case study of western North America using a high-resolution RCM Journal of Climate Diffenbaugh, N. S., Sloan, L. C. 2004; 17: 2927-2937
• Could CO2-induced land cover feedbacks alter near-shore upwelling regimes? Proceedings of the National Academy of Sciences Diffenbaugh, N. S., Snyder, M. A., Sloan, L. C. 2004; 101: 27-31
• Future climate change and upwelling in the California Current GEOPHYSICAL RESEARCH LETTERS Snyder, M. A., Sloan, L. C., Diffenbaugh, N. S., Bell, J. L. 2003; 30 (15)

  View details for DOI 10.1029/2003GL017647

  View details for Web of Science ID 000184867500002

• Orbital suppression of wind-driven upwelling in the California Current at 6 ka PALEOCEANOGRAPHY Diffenbaugh, N. S., Sloan, L. C., Snyder, M. A. 2003; 18 (2)

  View details for DOI 10.1029/2002PA000865

  View details for Web of Science ID 000183885200002

• Vegetation sensitivity to global anthropogenic carbon dioxide emissions in a topographically complex region GLOBAL BIOGEOCHEMICAL CYCLES Diffenbaugh, N. S., Sloan, L. C., Snyder, M. A., Bell, J. L., Kaplan, J., Shafer, S. L., Bartlein, P. J. 2003; 17 (2)

  View details for DOI 10.1029/2002GB001974

  View details for Web of Science ID 000183627400002

• Orbital suppression of wind driven upwelling in the California Current at 6 ka Paleoceanography Diffenbaugh, N. S., Sloan, L. C., Snyder, M. A. 2003; 18: 1051

  View details for DOI 10.1019/2002PA000865

• Future climate change and upwelling in the California Current Geophysical Research Letters Snyder, M. A., Sloan, L. C., Diffenbaugh, N. S., Bell, J. L. 2003; 30: 1823

  View details for DOI 10.1029/2003GL017647

• Vegetation sensitivity to global anthropogenic carbon dioxide emissions in a topographically complex region Global Biogeochemical Cycles Diffenbaugh, N. S., Sloan, L. C., Snyder, M. A., Bell, J. L., Kaplan, J. O., Shafer, S. L., Bartlein, P. J. 2003; 18: 1067

  View details for DOI 10.1029/2002GB001974

• Global climate sensitivity to land surface change: The Mid Holocene revisited GEOPHYSICAL RESEARCH LETTERS Diffenbaugh, N. S., Sloan, L. C. 2002; 29 (10)

  View details for DOI 10.1029/2002GL014880

  View details for Web of Science ID 000178888300030

• Global climate sensitivity to land surface change: The Mid Holocene revisited Geophysical Research Letters Diffenbaugh, N. S., Sloan, L. C. 2002; 29: 1476

  View details for DOI 10.1029/2002GL014880