A weather pattern called El Niño is causing extreme conditions in parts of Europe, Asia and the United States. What is it and why is it wreaking so much havoc?
When we think about warm weather we often focus on air temperature, but most of the planet’s heat is stored in its oceans and the temperature of one in particular is having a huge impact on the rest of the planet.
El Niño is the name given to a weather pattern which causes the planet to heat up. A natural phenomenon that comes around in cycles every two to seven years.
Scientists officially declare that the planet is in an El Niño phase when sea surface temperatures in the eastern Pacific – just off the coast of Mexico – rise 0.5 degrees above the long-term average. This year, that happened at the beginning of June.
During El Niño, the sea winds which normally blow from east-to-west across the Pacific Ocean switch directions. This means they push warm surface waters eastwards – from Australia to South America.
The unusually warm waters in that region release heat into the atmosphere, which creates wetter and warmer air.
This pushes up temperatures worldwide and causes extreme weather events being experienced in parts of Europe, Asia and the United States.
El Niño affects everything: food production, energy systems and global infrastructure.
The last time we experienced it was in 2016. It was the hottest year on record and the resulting droughts affected the food supply for over 60 million people
It looks like this year is on track to be even hotter.
Scientists predict that this El Niño phase will last until next spring. It’s expected to peak towards the end of the year.
As the world warms there will be more wildfires, droughts and flooding.
Most significantly, it could push the global average temperature over the 1.5 degree target which was set by the Paris Climate Agreement.
It might only be a temporary uptick, but it’ll give us an insight into how volatile the world will be in the near future because of climate change.
Today’s episode was written by Sara Weissel and mixed by Imy Harper.