After US scientists, WMO too says El Niño could raise temperatures globally later this year

File photo of a man covering himself and his child from the scorching Sun in New Delhi | ANI

New Delhi: After three consecutive years of a La Niña, which had a cooling effect on global mean temperatures, an El Niño is likely to develop later this year, the World Meteorological Organization (WMO) said in a statement Wednesday. The WMO’s announcement comes less than a fortnight after the US’s National Oceanic and Atmospheric Administration (NOAA) issued a similar alert.

While La Niña has a cooling effect, an El Niño causes mean temperatures to rise. The WMO is 90 per cent certain that the El Niño/La Niña Southern Oscillation (ENSO) will enter ‘neutral conditions’ from March to May. ‘Neutral conditions’ are when neither El Niño nor La Niña are present.

La Niña conditions have prevailed since September 2020, with forecasts showing that it is likely to weaken over the next few months. It refers to the large-scale cooling of sea surface temperatures in the central and eastern equatorial Pacific Ocean, which is known to cause excess rainfall in South Asia, Southeast Asia, and Australasia while causing drought in the Horn of Africa and South America. This is the opposite of an El Niño, which causes sea surface temperatures in the Pacific Ocean to rise. 

Both are naturally occurring climate phenomena with implications for global mean temperatures. 

“The first triple-dip La Niña of the 21st century is finally coming to an end. La Niña’s cooling effect put a temporary brake on rising global temperatures, even though the past eight-year period was the warmest on record,” said WMO Secretary-General Prof. Petteri Taalas, adding, “If we do now enter an El Niño phase, this is likely to fuel another spike in global temperature.” 

Early predictions not very accurate

While the chances of an El Niño developing early in the year are small, current forecasts say there is a 55 per cent chance it could develop between June and August. However, predictions at this time of year are subject to high uncertainty, with forecasts becoming more accurate around May, after the spring season has passed.

“Even though La Niña is coming to an end, we are likely to see latent impacts for some time to come and therefore, some of the canonical rainfall impacts of La Niña may still continue. The lingering impacts of multi-year La Niña is basically due to its long duration, and continuous circulation anomaly, which are different from the single-peak La Niña event,” says the WMO statement. 

Mercury to dip

The effects of global warming coupled with an El Niño could temporarily push global mean temperatures 1.5 degrees Celsius above pre-industrial levels. 

The world has already reached 1.1 degrees Celsius of warming since pre-industrial times. At 1.5 degrees Celsius, the effects of climate change will considerably worsen, scientists have said. 

The WMO had earlier said that there was a 93 per cent chance of at least one year between now and 2026 as being the hottest on record ever, with a 50:50 chance of the global temperature temporarily reaching 1.5 degrees Celsius above the pre-industrial era. At the moment, 2016 holds the record for the hottest year thanks to an El Niño coupled with climate change. 

Warm days ahead

India is already feeling the heat, with the IMD announcing Tuesday that this year’s February was the hottest since 1901. 

The all-India maximum temperature in February this year reached 29.54 degrees Celsius — 1.7 degrees Celsius higher than normal. The next few months are unlikely to bring respite, with the IMD forecasting higher than normal temperatures from March to May over most parts of India, barring the peninsular region. 

(Edited by Smriti Sinha)