How El Nino causes global temperatures to surge

STORY: The El Nino weather pattern has returned, bringing surging temperatures with it.

“We are likely to have one of the warmest years on record.”

For the first time in seven years, the World Meteorological Organization says El Nino has emerged in the tropical Pacific.

So what exactly is it?

El Nino is a natural climate pattern born out of unusually warm waters in the eastern Pacific... though scientists are not entirely sure what kicks off the cycle.

It's been linked to extreme weather conditions - from tropical cyclones to heavy rainfall to severe droughts.

The world's hottest year on record, 2016, coincided with a strong El Nino.

And the WMO says even that record could soon be broken.

WMO's Head of the Regional Climate Prediction Service Wilfran Moufouma Okia:

“The tropical Pacific Ocean is currently experiencing El Nino conditions and this is the result of a rapid and substantive change, both in the atmosphere and in the ocean. Now, to tell you whether it will be this year or next year is difficult, we don’t have the evidence here."

So what impact could El Nino have on global temperatures?

During an El Nino the southern U.S. sees cooler and wetter weather, while parts of the U.S. West and Canada are warmer and drier.

Australia, parts of Southern Asia and Central America usually endure extreme heat, drought and bushfires.

And increased rainfall could hit southern South America, the Horn of Africa and Central Asia.

“Last month, we issued what we call ‘The five years outlook’, so basically, we tried to anticipate the climate for the period 2023 to 2027. What we know is that throughout the next five years, we are likely to have one of the warmest years on record.”