Scientists Warn of Extreme Impacts Due to Potential Double Whammy of Record Sea Temperatures and El Niño

The tropical Pacific Ocean goes through La Niña and El Niño phases, in a cycle called El Niño-Southern Oscillation (ENSO). La Niña is characterised by cooler-than-average water temperatures, while El Niño delivers warmer-than-average temperatures. Both have a significant impact on weather around the world.

Over the past few years, ocean temperatures have steadily increased, despite the Pacific being firmly under the influence of the cooling La Niña phase. In fact, scientists revealed in January that the oceans had been at record-warm temperatures for the past four years. Then, climatologists noticed that the global sea surface temperature reached a new high in the middle of March.

Another worrying new study has shown that our planet has accumulated almost as much heat in the last 15 years as it did in the previous 45 years, with almost all of the extra energy going into the oceans.

To add fuel to the fire, weather models indicate that El Niño could begin to develop this summer. The transition to El Niño is usually accompanied by an spike in global temperatures, bringing with it effects like high heat, hazardous tropical cyclones, and a serious threat to delicate coral reefs.

Impacts of recent rapid ocean warming

For the first time, El Niño could contribute to global warming exceeding the 1.5°C-mark above pre-industrial levels of the middle to late 1800s. And 2024 could likely be the warmest year on record for the entire world, predicts Josef Ludescher, a senior scientist at Potsdam Institute for Climate Impact Research.

• The heating could result in the loss of marine species since more frequent and intense marine heat waves lead to mass mortality of sea life. This is especially damaging for coral reefs.

• Rise in heat in the upper ocean surface could result in more extreme weather, with hurricanes and cyclones picking up extra energy and becoming more long-lasting and intense.

• Warm water takes up more space owing to thermal expansion. This can significantly accelerate the melting of glaciers in Greenland and Antarctica and cause sea-level rise and coastal flooding.

• Oceans absorb nearly a quarter of greenhouse gas emissions, but warming will reduce their ability to absorb CO2. And if the oceans take up less CO2 in future, more will accumulate in the atmosphere, further warming the air and oceans.

**

For weather, science, space, and COVID-19 updates on the go, download The Weather Channel App (on Android and iOS store). It's free!