La Niña phenomenon has already passed its peak for 2021 | …

The La Niña 2020-2021 climate phenomenon has passed its peakthe United Nations Meteorological Agency announced on Tuesday, although its impact on temperatures, rain and storms will continue.

La Niña produces large-scale cooling of the surface temperature in the central and eastern parts of the equatorial Pacific Ocean, which occurs every two to seven years. The effect has a large impact on climate around the world and is the opposite of the warm phase produced by the El Niño Southern Oscillation.

In addition to cooling, La Niña is often associated with more rain in some parts of the world or more drought in others. The effects of La Niña started to be felt during the period August-September 2020, according to atmospheric and oceanic indicators.

“La Niña appears to have peaked in October-November as an event of moderate force,” the World Meteorological Organization (WMO) said.

However, the Geneva-based organization ensures that there is a 65% probability that La Niña will continue to show its effects during the period February-April. Thereafter, there is a 70% probability that the tropical Pacific will return to neutral conditions in the April to June cycle.

“El Niño and La Niña are the main drivers of the Earth’s climate system,” says WMO Secretary-General Petteri Taalas. “But natural weather events are now occurring against the backdrop of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather conditions, influencing seasonal rainfall patterns and making disaster prevention and management more difficult. “

The temporary cooling effects brought by La Niña were not enough to prevent 2020 from being one of the three hottest years on record.

“Despite the general cooling influence of La Niña, Earth temperatures are expected to be above normal in most parts of the world between February and April 2021,” notes the WMO.

According to the organization, the effects of La Niña and El Niño on average global temperatures are generally greatest in the second year of the event, although it remains to be seen to what extent the current La Niña will influence temperatures in 2021. “

Warmer temperatures

The WMO predicts that temperatures will be warmer in most parts of the world from February to April. Particularly in western, central and eastern Asia and the southern half of North America.

It also predicts that temperatures will be warmer than normal in most high latitudes in the north (except northwestern North America), parts of the south, central and east. of South America and in the equatorial and northern regions of Africa. .

Instead, temperatures are expected “below normal in the northern part of South America,” the organization said.

During the period from February to April, WMO predicts an unusual increase in precipitation in most countries of Southeast Asia, Australia and northern South America and southern Africa.

In contrast, in western and central Asia, as well as part of the Horn of Africa, central Africa, subtropical latitudes of North America, and parts of southeastern South America, it may rain less than normal.

The last La Niña, brief and relatively gentle, started to develop in November 2017 and ended in April 2018.