El Niño increases risks of compound meteorological disasters

The equatorial Pacific Ocean entered an El Niño phase in May as the sea surface temperature exceeded 0.5 degrees Celsius for five consecutive months till October, according to the latest monitoring report by China's National Climate Center (NCC). 

The type of El Niño event occurring this time is known as the Eastern Pacific (EP) El Niño, which is generally stronger than other types of El Niño events. Statistics show that from 1981 to 2020, there have been a total of 12 El Niño events, including three super-strong events, all of which were EP El Niño. These also constitute three of the strongest events in history since 1900, which were 1982-1983, 1997-1998 and 2015-2016.

This El Niño event is presently of moderate intensity. The NCC predicts that the event will continue until next spring.

Monitoring data from more than 10 historical El Niño events shows that for an increase of 1 degree Celsius in the sea surface temperature of the eastern equatorial Pacific, the global annual average temperature rises by 0.12 degrees Celsius. Through statistical analysis of historical events, El Niño events of moderate or higher intensity are estimated to increase the global annual average temperature by around 0.1 degrees Celsius. 

For instance, in 2016, during a super-strong El Niño event, the global average temperature was 0.94 degrees Celsius higher than the climatic average. It is predicted that this year will surpass the record of 2016, reaching an abnormal warming of around 1 degree Celsius. With the appearance of monthly warmest records since this May, the World Meteorological Organization (WMO) believes that 2023 may become the warmest year since records began in 1850.

El Niño will significantly impact global climate, exacerbating global warming and leading to higher frequencies, intensities and broader ranges of extreme weather events. It will increase the risks of compound meteorological disasters. It not only affects the ocean currents, sea temperatures and precipitation but also has a crucial impact on the intensity and paths of typhoons. 

Taking the super-strong El Nino event in 1997-1998 as an example, torrential rains and floods occurred in East Africa, while the rainy season in Indonesia, Papua New Guinea and northern Australia ended prematurely, leading to heatwaves, droughts and widespread forest fires. The 2015-2016 super-strong El Niño event triggered global climate anomalies, resulting in intensified extreme weathers like heavy rains, which caused floods, and intensified heatwaves and droughts.

Furthermore, global warming has significantly increased the peak oscillation of El Niño and La Niña events. On average, El Niño and La Niña events occur every two to seven years, and with global warming, their cycle has not significantly changed. However, their oscillation amplitude has increased significantly compared to before 1960. This implies that extreme weather climate events will occur more frequently and intensively.

NCC forecasts that, influenced by the El Niño, frost and snow disasters may occur in northern and northwestern China this winter. Heating energy demand could be higher than historical levels, resulting in periodic peaks in energy consumption. Additionally, there might be freezing rain and snow in southern regions. 

As predicted, this morning, the China Meteorological Administration (CMA) issued yellow warnings for cold waves, blizzards, and freezing. It is expected that from today until December 16, a strong cold wave will start from Xinjiang Uygur Autonomous Region and affect large parts of China. Over the next two days, heavy to severe snowfall is expected in areas like Shaanxi, Shanxi, Hebei, Beijing, Tianjin etc., with some places experiencing heavy snowstorms and freezing rain. In regions of north China and northern parts of the Yellow River-Huai River basins, temperatures are anticipated to approach or drop below historical minimums for this period.

(All images via CFP)