Weather and climate extremes with emerging features in 2023

The United Arab Emirates (UAE) saw record rainfall, with 254 millimeters falling in less than 24 hours, which was the most since records began in 1949, before the UAE was formed in 1971.

The United Nations expressed concern on April 8 about the effects of the drought in southern Africa after Zimbabwe became the third country in the region to announce a state of emergency.

Weather and climate extremes seem to occur more frequently than ever before and come with multiple features, according to an article in "Advances in Atmospheric Sciences," a journal of the Institute of Atmospheric Physics (IAP) under the Chinese Academy of Sciences.

Every month since June 2023 has beaten its own "hottest ever" tag, and March 2024 marked the 10th straight month of record global heat.

The globe has been hit by heat waves, extreme precipitation, wildfires, sandstorms and drought-to-flood abrupt transitions, which, in some cases, overlapped throughout 2023.

"One of the emerging features is the seasonal variation. Weather extremes are more likely to occur in unexpected seasons," said Robin Clark, co-author of the paper and senior scientist at the Met Office.

"Extreme high temperatures occured earlier in 2023. The southeastern Europe, the northern Africa, Southeast Asia and Brazil experienced a very hot spring. The highest temperature exceeded 40 degrees Celsius in some places," said Zhang Wenxia, first author of the paper and research associate at the IAP.

The Northern Hemisphere was hit by heat waves in many places in July 2023. These spatially complex heat waves could occur in multiple food-producing areas at the same time, posing a significant threat to global food security.

Weather and climate extremes also occur successively. A drought-to-flood transition could have greater impacts than a single extreme event. A long-term drought continued in South America. In California and in the Horn of Africa, however, prolonged droughts have been replaced by excessive rains that lead to floods.

In addition, the interaction increases between climate extremes and ecosystems. Large-scale wildfires occurred in 2023. The carbon emissions produced by wildfires and their damage to carbon sinks are not to be overlooked in reaching global carbon neutrality.

These increasing and intensifying extreme weather events top the Global Risks Report from the World Economic Forum.

"To respond more effectively to extreme climate change," Zhang notes, "we must pay attention to the trend as well as the emerging features of the extreme events."

Samy Ashraf Anwar Rateb, a researcher at the Egyptian Meteorological Authority, emphasized that to reduce extreme weather events, "measures must be taken to combat global warming, and the world must work hard to reduce carbon emissions and the use of fossil fuels."

Researchers believe that, in addition to increasing scientific awareness, early warning is also required in response to extreme events. "This requires joint efforts from the international community, especially strengthened collaboration between the northern and southern regions," said Dr Li Chao, co-author of the paper from the Max Planck Institute for Meteorology.

(With inputs from Xinhua; Cover: Following days of rain, floodwaters surround homes and vehicles in the Planada community of Merced County, California, on January 10, 2023. /CFP)