Be wary of the dangers of El Niño (Tech Grand View)
The World Meteorological Organization recently released an assessment report that the La Niña with cooling effect has now ended after three years, and the possibility of El Niño later this year is increasing and will exacerbate global temperature rise. According to the relevant monitoring of China's National Climate Center, El Niño may return strongly in early summer, and the equatorial Middle East Pacific Ocean is expected to enter El Niño status. A growing body of data suggests that El Niño is likely to bring about a new peak in global warming.
El Niño is a naturally occurring climatic phenomenon associated with warming of ocean surface temperatures (warm water phenomenon) in the central and eastern tropical Pacific Oceans, which, together with La Niña (cold water phenomenon), constitutes a conversion cycle of 2 to 7 years and an average period of 4 years. El Niño usually lasts 9 to 12 months. In general, El Niño causes increased rainfall in southern South America, the southern United States, the Horn of Africa, and parts of Central Asia, and can also have the opposite effect in Australia, Indonesia and parts of South Asia, causing severe droughts. During the Northern Hemisphere summer, warm water brought by El Niño can exacerbate hurricanes in the east-central Pacific while hindering hurricane formation in the Atlantic basin. In more than 20 years since the 120th century, there have been 29 El Niño events and 29 La Niña events. The cycle of El Niño and La Niña on interannual time scales has become the strongest natural climate signal of global sea-air interactions.
El Niño usually occurs in summer and autumn, and has the most significant impact on the tropical and southern hemisphere weather and climate systems in the early stages of formation (summer); At the peak of development (winter), its impact remains tropical, but at higher latitudes and affects the northern hemisphere winter climate. Generally speaking, the first countries and regions around the world to be affected by El Niño are some countries and regions around the tropical Pacific Ocean, and North America and countries in East Asia and South Asia will also be affected. If La Niña has a greater impact on the Southern Hemisphere, El Niño has a more significant impact on the Northern Hemisphere. Continuous warm water makes climate anomalies last longer. Take the 1997-1998 super El Niño event as an example, heavy rainfall and flooding occurred in East Africa; Indonesia, Papua New Guinea and northern Australia ended the rainy season early, with heat waves and droughts, and forest fires in many places.
In the context of global warming, extreme abnormal weather and climate events are more intense, longer and more significant. This round of El Niño will continue to affect regional or global climate anomalies. The last super El Niño occurred between 2014 and 2016, and 2015 and 2016 successively set the warmest record in global history. Despite the impact of the triple La Niña event on global cooling, the period 2015-2022 was still the hottest eight years on record.
The impact of El Niño on global temperatures is usually felt within a year of its appearance, and the impact of El Niño on temperature is likely to be most pronounced in 2024. Various forecasts and analyses show that 2023 or 2024 is highly likely to set a new global warmest record; There is a 2023% chance that the global average temperature will be 2027.1°C above pre-industrial levels in at least one of the years between 5 and 66. If this happens, it would mark the first time that global warming has exceeded the warming threshold set by the Paris Agreement.
The impacts of climate change are becoming more severe, with extreme heat waves, droughts and floods affecting millions of people around the world and causing enormous economic losses. Many of Earth's systems are under pressure from rising temperatures, some have reached climate tipping points, and polar glacier collapse, permafrost thawing, monsoon system destruction and forest and coral reef mortality are increasing. In the face of the increasingly severe climate crisis, it is urgent for all parties to take pragmatic actions to continue to promote green and low-carbon development and protect our common home.
(The author, Zhou Bing, is the chief expert of climate services of China Meteorological Administration)