2018 summer extreme temperatures in South Korea and their intensification under 3 °C global warming

Abstract

With the acceleration in global warming, extreme hot temperatures have emerged as one of the most prominent risks. In this study, we characterize the unprecedented extreme temperatures that occurred in Korea in summer 2018, and attempt to explain how this locally observed extreme event can be interpreted in the context of 2°C and 3°C global warming above the pre-industrial level. To better resolve geographically diverse climate features and enhance confidence in future changes, three global projections are dynamically downscaled using three regional climate models that are customized over Korea and the systematic biases are statistically corrected using quantile mapping. In July and August 2018, abnormally high maximum temperatures (Tmax) were observed over the entire territory of South Korea. Beyond the increase of mean value, Tmax at individual stations departed significantly from the typical Gaussian distribution of climatological Tmax due to the dramatic changes in the extent and shape of upper tails. The distinct behaviors of Tmax that appeared in 2018 largely represent the statistical analog of the distribution pattern expected under 3°C global warming based on finescale climate projections. This implies that statistically extremely rare events like that of summer 2018 will become increasingly normal if global average temperature is allowed to increase by 3°C. More importantly, the extreme heat stress measured by the wet-bulb globe temperature is projected to intensify the risks to a level never before seen in contemporary climate. This study is timely and relevant to the need to identify how the globally aggregated warming target temperature can be disaggregated into regional impacts.

Asymmetric Expansion of Summer Season on May and September in Korea

“…The present model projects that the summer warming rate (0.68°C decade −1 ) will be greater than the annual warming rate (0.56°C decade −1 ) throughout the future period (2018-2099). These results are consistent with previous studies which suggested an acceleration of the summer warming trend resulted from an increase in the mean temperature as well as frequency and magnitude of heatwave (Min et al 2015;Choi and Lee 2019;Im et al 2019). Conversely, considerable changes are projected for the beginning date of winter (11 and 24 days) than those for the ending date of winter (6 and 15 days) for the middle and end of the twenty-first century, respectively.…”

An Evaluation of Temperature-Based Agricultural Indices Over Korea From the High-Resolution WRF Simulation

“…Finer-scale, longer-term meteorological forecast data needs keen attention. In particular, since extreme hot temperatures have emerged as one of the disaster-related threats in Korea due to accelerated global warming (Im et al, 2017(Im et al, , 2019, the agricultural sector is very likely to be adversely affected if preparations are not made in a timely manner (e.g., Shin Y.-H. et al, 2017;Jo et al, 2020). From the perspective of climate change adaptation, the value of meteorological forecast data will continue to enhance.…”

“…The intensity and frequency of extreme temperature during summer in South Korea have gradually increased in accordance with rising global mean temperature (Im et al, 2015(Im et al, , 2017. As global warming accelerates, the uncommonly high Tmax under the current climate is likely to become increasingly normal (Im et al, 2017(Im et al, , 2019. Accordingly, the regionally tailored meteorological information will be greatly helpful in minimizing the foreseeable damage amid an alarming rise of global warming.…”

Performance Evaluation of CMIP5 and CMIP6 Models on Heatwaves in Korea and Associated Teleconnection Patterns

“…An increase in anthropogenic greenhouse gases has increased heatwaves in East Asia including Korea (Im et al, 2019; D. Lee et al, 2016; Min et al, 2014; Sun et al, 2014). However, the simulated performance of heatwaves during historical experiments shows many differences between models (Guo et al, 2017; Seo et al, 2018).…”

“…An increase in anthropogenic greenhouse gases has increased heatwaves in East Asia including Korea (Im et al, 2019;D. Lee et al, 2016;Min et al, 2014;Sun et al, 2014).…”