Changes in a Suite of Indicators of Extreme Temperature and Precipitation Under 1.5 and 2 Degrees Warming
Following the 2015 Paris agreement, the Intergovernmental Panel on Climate Change was tasked with assessing climate change impacts and mitigation options for a world that limits warming to 1.5 C in a special report. To aid the scientific assessment process three low-warming ensembles were generated over the 21st century based on the Paris targets using NCAR-DOE community model, CESM1-CAM5. This study used those simulation results and computed ten extreme climate indices, from definitions created by the Expert Team on Climate Change Detection and Indices, to determine if the three different scenarios cause different intensity and frequency of extreme precipitation or temperature over the 21st century. The temperature indices show widespread significant change, while the behavior of precipitation indices reflects the larger role that internal variability plays, even by the end of the century, but large regions of significant differences emerge nonetheless. Our results show that even for scenarios that are separated by only half of a degree in global average temperature, the statistics of extremes are significantly different.