Temperature and Precipitation Extremes in the 20th and 21st Century As simulated by Climate Models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4)

Changes in Climate Extremes

How will temperature and precipitation extremes (heat waves, droughts, etc.) change in the future? You can get some answers here. This webapp allows the user to map and explore the extreme temperature and precipitation indices projected by global climate models and observations. Click Generate Maps to get started.

The variables are those defined by Frich et al. (2002) and Tebaldi et al. (2006) that were archived as part of the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset (Meehl et al. 2007). The variables are derived from daily values in IPCC AR4 model simulations of the 20th or 21st century (including B1, A1B, & A2 scenarios for greenhouse gasses). Observations were constructed using the Global Historical Climate Network.

Acknowledgement: We acknowledge the modeling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) and the WCRP's Working Group on Coupled Modeling (WGCM) for their roles in making available the WCRP CMIP3 multi-model dataset. Support of this dataset is provided by the Office of Science, U.S. Department of Energy.
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Sample Figure Description: The difference in the Heat Wave Duration Index (HWDI) in days between the 21st and the 20th century. The HWDI is defined as the maximum period in each year of at least 5 consecutive days where the maximum temperature is at least 5 degrees C warmer than the daily climatology from the 1961-1990 period; for the 20th century simulations, this includes all years: 1900-1999. Click here for more details.

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