Probability of record-shattering climate extremes depends on rate of global warming
Abstract
Recent climate extremes such as the 2021 heatwave in the Pacific Northwest, the 2020 Siberian heat anomaly, the 2018/19 angriest summer in Australia as well as the 2003 European and 2010 Russian heatwaves have broken long-standing records by large margins. Such extremes unprecedented in the observational period often have substantial impacts due to a tendency to adapt to the highest intensities, and no higher, experienced during a lifetime. Here, we show that models project not only more intense extremes but also events that break previous records by much larger margins. These record-shattering extremes, nearly impossible in the absence of warming, are likely to occur in the coming decades. Previous studies have demonstrated that the level of global warming primarily determines the return periods and return levels of temperature and precipitation extremes. In contrast, for the type of record-shattering extremes emphasized here, where the extreme is placed in the context of previous record events rather than a reference climatology, it is the warming rate, and particularly the accelerating warming rate after periods of little to no warming, that determines the probability of record-shattering events. For a linear warming trend the event probability converges to a constant in time, with higher warming rates implying higher probability. If a period of no or weak warming is followed by a rapid linear warming period, the event probability rapidly increases and converges faster for higher warming rates. Therefore, the future probability of record-shattering extremes depends on the emission pathway.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC22A..01F