Projected Changes in Climate Extremes Using CMIP6 Simulations Over SREX Regions

Abstract

This paper presents projected changes in extreme temperature and precipitation events by using Coupled Model Intercomparison Project phase 6 (CMIP6) data for mid-century (2036–2065) and end-century (2070–2099) periods with respect to the reference period (1985–2014). Four indices namely, Annual maximum of maximum temperature (TXx), Extreme heat wave days frequency (HWFI), Annual maximum consecutive 5-day precipitation (RX5day), and Consecutive Dry Days (CDD) were investigated under four socioeconomic scenarios (SSP1-2.6; SSP2-4.5; SSP3-7.0; SSP5-8.5) over the entire globe and its 26 Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) regions. The projections show an increase in intensity and frequency of hot temperature and precipitation extremes over land. The intensity of the hottest days (as measured by TXx) is projected to increase more in extratropical regions than in the tropics, while the frequency of extremely hot days (as measured by HWFI) is projected to increase more in the tropics. Drought frequency (as measured by CDD) is projected to increase more over Brazil, the Mediterranean, South Africa, and Australia. Meanwhile, the Asian monsoon regions (i.e., South Asia, East Asia, and Southeast Asia) become more prone to extreme flash flooding events later in the twenty-first century as shown by the higher RX5day index projections. The projected changes in extremes reveal large spatial variability within each SREX region. The spatial variability of the studied extreme events increases with increasing greenhouse gas concentration (GHG) and is higher at the end of the twenty-first century. The projected change in the extremes and the pattern of their spatial variability is minimum under the low-emission scenario SSP1-2.6. Our results indicate that an increased concentration of GHG leads to substantial increases in the extremes and their intensities. Hence, limiting CO2 emissions could substantially limit the risks associated with increases in extreme events in the twenty-first century.

Projected Air Temperature Extremes and Maximum Heat Conditions Over the Middle-East-North Africa (MENA) Region

“…Figure 2 Published in partnership with CECCR at King Abdulaziz University with relevant global (Sillmann et al 2013b) and regional (Lelieveld et al 2016) studies. These results are also in agreement with recent CMIP6 based studies (Vogel et al 2020;Almazroui et al 2021), in which similar patterns of warming have been reported. According to Almazroui et al (2021), the CMIP6 multimodel ensemble indicates a substantial increase in TXx over the Mediterranean region and adjacent parts of Europe, in contrast with areas near the tropics.…”

“…These results are also in agreement with recent CMIP6 based studies (Vogel et al 2020;Almazroui et al 2021), in which similar patterns of warming have been reported. According to Almazroui et al (2021), the CMIP6 multimodel ensemble indicates a substantial increase in TXx over the Mediterranean region and adjacent parts of Europe, in contrast with areas near the tropics. The stronger warming at the northern part of the MENA domain can be linked to soil moisture feedbacks (Russo et al 2019) and precipitation deficits (Mueller and Seneviratne 2012), which can amplify heat conditions.…”

Recent Climate Change in the Lake Kyoga Basin, Uganda: An Analysis Using Short-Term and Long-Term Data with Standardized Precipitation and Anomaly Indexes

“…There are also high frequencies of extreme events such as droughts and floods [12][13][14][15][16][17]. Global projections show an increase in the frequency and intensity of precipitation and temperature extremes, with the increases related to an increase in greenhouse gas concentrations, according to a special report on managing the risk of extreme events and disasters to advance CC adaptation (SREX) [18]. The national oceanic and atmospheric administration (NOAA) of the United States of America declared that July 2021 was the hottest month in recorded history [19].…”

Compound Effects of Climate Change on Future Transboundary Water Issues in the Middle East

“…We also recognize that our results are based on the very high emissions scenario, SSP5‐8.5, which represents the worst‐case outcome. However, similar spatial patterns with smaller magnitude in the future changes are expected for lower emissions scenarios such as SSP2‐4.5 (Almazroui et al., 2021; Carvalho et al., 2021; IPCC, 2021). The issues discussed above should be taken into consideration when interpreting the CMIP6 simulations for regional long‐term planning.…”