Changes in compound hot and dry day and population exposure across China under climate change

Abstract

Hot and dry extremes have co‐occurred with global warming, causing worse threats than single climate extremes. We analyse the compound hot and dry day (CHDD) and population exposure (Epop) across China based on observations and 11 global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6. The bias‐corrected GCMs, particularly the two‐stage multivariate quantile mapping‐corrected ones, perform better than the raw ones in catching changes in CHDD but they all overestimate CHDD and Epop. More CHDDs occur in the southeast (SE), north (NC) and northwest (NW) China with increasing trends over regions stretching from the northeast (NE) to southwest (SW) China. Despite the declined CHDD, historical Epop has generally increased by the increased population. Future projections in the SSP5‐8.5 experiment indicate an overall increase of CHDD and Epop at 1.5°C warming and an increasing Epop to dangerous CHDD at 2°C warming. SW, NE and the Tibetan Plateau need effective measures of adaptation to reduce sufferings from CHDD under climate change.

Global Increases in Lethal Compound Heat Stress: Hydrological Drought Hazards Under Climate Change

“…However, here we show that the CHD hotspots are located not only in the midlatitudes, as suggested by Ridder et al ( 2020), but also have a high likelihood of occurrence in coastal regions and high latitudes where the RH is relatively high. Moreover, we evaluate the shifts of bivariate risks by using copula functions, which reveal typically higher risks than previous projections (Feng et al, 2021;McKinnon et al, 2021). As human activities such as urbanization and hydrological engineering might impact river discharge, more attention should be paid to detect and attribute the impacts of human activity versus climate change on CHD projections.…”

Climate Change Determines Future Population Exposure to Summertime Compound Dry and Hot Events

“…Population exposure to CDHEs is a commonly used metric in evaluating the impact of CDHEs on human society (Feng, Sun, et al, 2021;Liu et al, 2021). For example, Feng, Sun, et al (2021) investigated population exposure to CDHEs based on observations and global climate models (GCMs) across China. With simultaneous increases in population and CDHEs in the future, population exposure to CDHEs would be exacerbated (Feng, Sun, et al, 2021;Liu et al, 2021).…”

“…For example, Feng, Sun, et al (2021) investigated population exposure to CDHEs based on observations and global climate models (GCMs) across China. With simultaneous increases in population and CDHEs in the future, population exposure to CDHEs would be exacerbated (Feng, Sun, et al, 2021;Liu et al, 2021). Wu, Hao, et al (2021) projected a significant increase in the occurrence of CDHEs and corresponding exposures under 1.5°C and 2.0°C of warming in China.…”

“…For example, Feng, Sun, et al. (2021) investigated population exposure to CDHEs based on observations and global climate models (GCMs) across China. With simultaneous increases in population and CDHEs in the future, population exposure to CDHEs would be exacerbated (Feng, Sun, et al., 2021; Liu et al., 2021).…”

Asia Faces a Growing Threat From Intraseasonal Compound Weather Whiplash

“…On average, they have exhibited a 3–4‐year return period in the history over the hotspots and 5–10‐year return period elsewhere. The three historical hotspots were dominated by the drought‐CWE type (Figure 3e), but all three hotspots would be eventually overwhelmed by heat‐drought CWEs in the far future under SSP5‐8.5 (Figure 3m), largely due to the ever‐stronger association between heat and drought in a warmer climate (Y. Feng et al., 2022). However, the changes in dominate type of typical CWEs over the three hotspots follow disparate paths as highlighted in the last three columns in Figure 3.…”