Science

Another El Nino is likely on its way: Here's what to expect

Fires north of the Arctic Circle. Record-setting temperatures in England. More than 60 dead in Japan, and 70 in Quebec due to heat-related causes. Now NOAA is forecasting a 70 per cent chance of El Nino developing this winter.

Experts say the weather event is not expected to be as bad as 2015-2016

A couple walks by the shore, where water levels are low, in Dartmoor, England during a severe heat wave last month. (Ben Birchall/Associated Press)

Fires north of the Arctic Circle. Record-setting temperatures in England. More than 60 dead in Japan and 70 in Quebec due to heat-related causes. A fast-moving fire that wiped out an entire Greek town, killing more than 90 people.

At the moment, drought and fire are ravaging much of the planet. This past June was the fifth warmest June on record, and the 402nd consecutive month above the 20th century average.

And the turbulent weather could continue, as the U.S. National Oceanic and Atmospheric Administration's Climate Prediction Center says there is a 70 per cent chance of another El Nino occurring this winter.

El Nino is part of Earth's natural process, characterized by a warming in the Pacific Ocean with repercussions across the globe, including higher temperatures and greater precipitation in various regions. 

One of the strongest El Ninos on record occurred from the fall of 2015 well into 2016. In Canada, it brought the second-warmest winter since record-keeping began in 1948, while the World Health Organization reported that 60 million people were affected globally.

This video illustrates the drought that occurred across northern Europe at the end of July:

Following a summer of wild heat, it may seem worrying to know that another El Nino is on its way. But there's no need to panic.

"We're probably looking at a weak to maybe moderate [El Nino], but certainly nothing like 2015-2016," said Mike Halpert, deputy director of NOAA's Climate Prediction Center. "That's just not in the cards."

Halpert notes there's still time for the weather agency to refine its El Nino forecast — the next one will be issued on Aug. 9 — if it develops at all.

But if it does develop, the effects in Canada will be felt more in the winter, particularly in the West, where temperatures would be warmer than average.

It's another story around the world. Typical El Nino-related effects are shifts in weather patterns: rain moves from areas where it would normally occur, leaving some areas in drought. After the El Nino event of 2015–2016, for example, the world's coral experienced the worst bleaching events ever seen.

Warming world

This year has been a La Nina year — the opposite of El Nino: Instead of waters being warmer than usual in the Pacific, they're cooler than normal.

But it didn't seem to matter to the warming planet. The global temperature from January to May broke the record for a La Nina year.

If an El Nino does manifest by the end of the year, it won't push the global temperature shockingly upward. Rather, it will just slightly raise the planet's temperature higher than it would have otherwise been. 

That's because the planet's response to an El Nino takes time, says Derek Arndt, chief of NOAA's National Centers for Environmental Information (NCEI) monitoring branch.

And though this has been the summer of heat — with almost two months to go — he said forecasters aren't expecting it to surpass the hottest year on record, which occurred in 2016. 

But it will still be one for the books — and Arndt says that's concerning.

"It's really important to consider that where we finish this year — [whether it] be third or fourth or fifth or something like that — it will be warmer than anything we may have seen five years ago," Arndt said.

"We're in a new neighbourhood, and we're competing in a new neighbourhood, and we have left the climate of the 20th century in the dust — and we're in the process of leaving the climate of the last decade behind."

ABOUT THE AUTHOR

Nicole Mortillaro

Senior Science Reporter

Based in Toronto, Nicole covers all things science for CBC News. As an amateur astronomer, Nicole can be found looking up at the night sky appreciating the marvels of our universe. She is the editor of the Journal of the Royal Astronomical Society of Canada and the author of several books. In 2021, she won the Kavli Science Journalism Award from the American Association for the Advancement of Science for a Quirks and Quarks audio special on the history and future of Black people in science. You can send her story ideas at nicole.mortillaro@cbc.ca.