Increased population exposure to precipitation extremes under future warmer climates

Abstract

Precipitation extremes are among the most dangerous climate-related hazards, and these hazards often cause large socioeconomic losses and exert severe human health impacts each year. It is thus crucial to assess future exposure changes to precipitation extremes under different warming scenarios to improve the mitigation of climate change. Here, we project future exposure using a set of Coupled Earth System Model low-warming simulations and RCP8.5 large ensemble simulations. We find that the precipitation extremes are projected to significantly increase over the coming century under different future warming scenarios at both the global and regional levels. Compared to a 1.5°C warmer climate, the 0.5°C of additional warming under a 2.0°C warmer future would increase the number of days of global aggregate precipitation extremes by approximately 3.6% by the end of this century. As a result, the global aggregate exposure is reported to increase by approximately 2.3% if the surface air temperature increases to 2.0°C rather than 1.5°C. An increase in exposure is also obvious for most regions across the world, and the largest increase in the future occurs over North Asia in response to the 0.5°C of additional warming. Furthermore, exposure would increase more rapidly if the temperature increased following the RCP8.5 pathway. The exposure increase varies at the regional level, but in most cases, climate change shows more influential than that of the population; in addition, this influence does not depend on the population outcomes used here. OPEN ACCESS RECEIVED

Significant Increase of the Global Population Exposure to Increased Precipitation Extremes in the Future

“…al., 2016). With continuous rapid warming expected in the future, increases are expected to be much larger than the current climates across the world (e.g., Zhou et al, 2014;Chen et al, 2020a); this is also validated by the results of the latest CMIP6 models (Figure 1). In response to future warming, the ensemble mean of the CMIP6 models presents a consistent increasing trend of days of precipitation extreme averaged over global lands, but it varies among the scenarios.…”

“…Recent studies have shown that global aggregate exposure to precipitation extremes is projected to increase in the future (Liao et al, 2019;Chen et al, 2020a), by approximately 2.3% if the temperature increases by 2.0 o C relative to the pre-industry era rather than by 1.5 o C calculated from the CESM simulations (Chen et al, 2020a).…”

“…At the national level, future exposure over China shows a linear upward trend (Zhan et al, 2019;Chen and Sun, 2020) as well as over South America (Li et al, 2020). However, low agreement is reported for the responsibility of these exposure changes, mainly due to the different scenarios and different models used (Liu et al, 2017;Liao et al, 2019;Chen et al, 2020a). Furthermore, to date, these analyses are implemented mainly on the basis of CMIP5 simulations, and their potential changes have not been revealed by CMIP6 model simulations.…”

Statistical characteristics of extreme daily precipitation during 1501 BCE–1849 CE in the Community Earth System Model

“…The focus of this study is on the long-term changes and characteristics of extreme daily precipitation on a global scale rather than on the characteristics or impacts of a handful single events. Therefore, we use the daily precipitation from CESM as it is in the next section, i.e., without applying any further corrections, such as bias correction (e.g., Chen et al, 2020) or downscaling methods (e.g., Yang et al, 2012). Still, we take into account the differences between ERA5 and CESM in the magnitudes of extreme precipitation when interpreting our results and discussing possible implications in the conclusions.…”

Reduction in extreme climate events and potential impacts by the use of technological advances

“…The overall damage and costs directly linked with extreme events between 1997 and 2016 reached about $3.16 trillion (Eckstein et al ., 2017). Without effective progress in reducing greenhouse gas emissions, the frequency and intensity of extreme weather/climate events and the losses induced by these events are expected to rapidly increase in the 21st century (IPCC, 2012; Chen et al ., 2020). For example, the global gross domestic product (GDP) might reduce sharply by >30% for a 4°C increase in global warming (Burke et al ., 2018), greater than the reduction in the Great Depression when global trade fell by 25%.…”