Precipitation variability increases in a warmer climate

Abstract

Understanding changes in precipitation variability is essential for a complete explanation of the hydrologic cycle’s response to warming and its impacts. While changes in mean and extreme precipitation have been studied intensively, precipitation variability has received less attention, despite its theoretical and practical importance. Here, we show that precipitation variability in most climate models increases over a majority of global land area in response to warming (66% of land has a robust increase in variability of seasonal-mean precipitation). Comparing recent decades to RCP8.5 projections for the end of the 21st century, we find that in the global, multi-model mean, precipitation variability increases 3–4% K−1 globally, 4–5% K−1 over land and 2–4% K−1 over ocean, and is remarkably robust on a range of timescales from daily to decadal. Precipitation variability increases by at least as much as mean precipitation and less than moisture and extreme precipitation for most models, regions, and timescales. We interpret this as being related to an increase in moisture which is partially mitigated by weakening circulation. We show that changes in observed daily variability in station data are consistent with increased variability.

Climatic Changes and Their Relation to Weather Types in a Transboundary Mountainous Region in Central Europe

“…At first glance, such contrasting findings are in line with the results of a multi-model study by Pendergrass et al [95]. They demonstrate that warmer temperatures lead to increasing precipitation variability worldwide-temporal scales are used from 24 h to a few decades.…”

Observed Impacts of Anthropogenic Climate Change on Wildfire in California

“…In these regions, fire risk may be promoted by wetdry events (see Methods), when increased fine-fuel biomass due to high precipitation total in one year dries out due low precipitation in a subsequent year. Climate models do project increased interannual variability of California precipitation at a range of temporal scales (Berg & Hall, 2015;Pendergrass et al, 2017;Polade et al, 2014;Polade et al, 2017;Swain et al, 2018), but the multi-model mean suggests no clear anthropogenic promotion of wet-dry events as of 2018 (Figures 5f and S16). The observed centennial increase in wet-dry event frequency occurred mainly as a result of an increase in interannual variability in total annual precipitation ( Figure S16).…”

Toward a Resilient Global Society: Air, Sea Level, Earthquakes, and Weather

“…This notion of irreducible uncertainty in regional climate (Hawkins et al, 2016) has been met with a certain level of dismay in policy and decisionmaking circles, where such projections inform climate adaptation measures. While the projected increase in global mean precipitation is modest (around 3%/°C; Kharin et al, 2013), much larger increases in extreme precipitation events are expected (5-10%/°C; Donat et al, 2016;Neelin et al, 2017;Pendergrass et al, 2017). While the projected increase in global mean precipitation is modest (around 3%/°C; Kharin et al, 2013), much larger increases in extreme precipitation events are expected (5-10%/°C; Donat et al, 2016;Neelin et al, 2017;Pendergrass et al, 2017).…”

“…Indeed, the increasing risk of future megadrought may be driven primarily by persistent warmth and temperature-driven aridity, as opposed to decreases in precipitation (Cook et al, 2015). Thus, shifts in the temporal and spatial character of the hydrologic cycle could become far more consequential than changes in its mean state (Donat et al, 2016;Dong et al, 2018;Pendergrass et al, 2017;Polade et al, 2017;Swain et al, 2018).…”

“…Similarly, investing in an infrastructure that is truly climate resilient will depend on the understanding that incremental changes in mean climate belie far greater changes in the frequency of unprecedented extreme events (Diffenbaugh et al, 2017;Huang et al, 2018;Pendergrass et al, 2017;Swain et al, 2018). Similarly, investing in an infrastructure that is truly climate resilient will depend on the understanding that incremental changes in mean climate belie far greater changes in the frequency of unprecedented extreme events (Diffenbaugh et al, 2017;Huang et al, 2018;Pendergrass et al, 2017;Swain et al, 2018).…”