Scientists have always understood El Niño to be a phenomenon that temporarily alters global weather, with conditions returning to “normal” when it dissipates. However, climate change is expected to change what “normal” looks like.

As the planet warms, extreme El Niño years are likely to become more common. Our research suggests the tropical Pacific could remain in an El Niño-like state for centuries – even if the world reaches net zero carbon emissions – and extreme El Niño years would occur more often.