The year 2023 marked the hottest year since 1850. Alongside record-breaking temperatures, the world experienced frequent extreme weather and climate events, including heatwaves, heavy rainfall, rapid shifts between droughts and floods, wildfires, and dust storms.
Recently, a group of scholars from the Institute of Atmospheric Physics, Chinese Academy of Sciences, in collaboration with experts from the UK Met Office, Sorbonne University in France, Max Planck Institute for Meteorology in Germany, Argentine Institute of Glaciers and Environmental Sciences, and Shanghai Typhoon Institute of the China Meteorological Administration, published a summary review in the "News & Views" section of Advances in Atmospheric Sciences. They covered the major extreme events of 2023, detailing their fundamental facts, impacts, and key physical processes. Through a comprehensive perspective spanning from the past to the future, they aimed to further understand the variability of climate internally and the role of anthropogenic climate change.
Review of Major Extreme Weather and Climate Events Globally in 2023
The increasing frequency and intensity of extreme weather and climate events have been identified as the primary global risks for the next decade in the latest Global Risks Report by the World Economic Forum. To effectively address these changes, it is crucial not only to monitor their strengthening trends but also to observe the emerging new features of these extreme events, which pose new challenges to their study.
The focus of the article is on the emerging new features of these extreme events. Specifically, there has been a shift in the timing of extreme heat events, with many regions experiencing extreme heat (even exceeding 40°C) in spring 2023, including southwestern Europe, North Africa, Southeast Asia, and Brazil. Additionally, there is an increase in simultaneous occurrences of heatwaves in multiple locations, such as the heatwaves that struck multiple areas in the Northern Hemisphere in July 2023, posing significant threats to global food security by affecting multiple grain-producing regions simultaneously.
For extreme precipitation events, the intensity of extreme rainfall has been greatly amplified by the strong moisture transport brought by intense cyclones. For example, the torrential rains in Beijing-Tianjin-Hebei in July and the flooding in Libya in September 2023 both broke historical records, with the former influenced by super typhoons DusuRay and Khanun and the latter by the Mediterranean Hurricane Daniel.
Regarding drought, some regions continue to experience prolonged drought (such as central South America), while others (like California and the Horn of Africa) have transitioned from years of drought to flooding.
Wildfires and dust storms have also intensified, with widespread wildfires in Hawaii in August 2023 and wildfires in Canada from spring to autumn 2023, as well as a dust storm in Mongolia in April 2023, highlighting the increasing interaction between extreme events and ecosystems.
"One of the new features of extreme events is their seasonal variation; they are now occurring in seasons where they were previously less likely," explained Robin Clark, a senior researcher at the UK Met Office Hadley Centre.
Researchers also emphasize the need to pay attention to the compound characteristics of extreme events, including rapid transitions between drought and flooding, which often have a greater impact than individual extreme events. Furthermore, the interaction between extreme climate events and ecosystems is strengthening, with carbon emissions from wildfires and their destruction of natural carbon sinks posing significant challenges to achieving global carbon neutrality goals. These issues present new challenges to the study of extreme events.
In addition to advancing scientific understanding, effective responses to extreme events require early warning systems. This aligns with the ambitious goal of the United Nations' "Early Warnings for All" initiative launched in 2022, aiming to ensure that all people worldwide have access to early meteorological warning systems by the end of 2027 to cope with increasingly extreme weather and climate changes.
Researchers point out that achieving this goal remains challenging, particularly in many underdeveloped regions. "This requires concerted efforts from the international community, especially strengthening cooperation between the Global North and the Global South. For example, the 'Earth Virtualization Engines' (EVE) initiative initiated by the Max Planck Institute for Meteorology in Germany provides a new paradigm for international cooperation and has received responses from many countries and industries. By integrating numerical simulation, high-performance computing, artificial intelligence, and user needs, its goal is to provide kilometer-scale, more effective climate prediction information for all users globally to better address extreme climate change," said Dr. Chao Li, one of the authors from the Max Planck Institute for Meteorology in Germany.
For more information, refer to the related paper: DOI: 10.1007/s00376-024-4080-3.
