The Southern Ocean absorbs more heat than any other ocean on Earth, and the impacts will be felt for generations

Southern Ocean heat uptake accounts for almost all the planet’s ocean warming, thereby controlling the rate of climate change.

Source: The Southern Ocean absorbs more heat than any other ocean on Earth, and the impacts will be felt for generations

Over the last 50 years, the oceans have been working in overdrive to slow global warming, absorbing about 40% of our carbon dioxide emissions, and over 90% of the excess heat trapped in the atmosphere.

But as our research published today in Nature Communications has found, some oceans work harder than others.

We used a computational global ocean circulation model to examine exactly how ocean warming has played out over the last 50 years. And we found the Southern Ocean has dominated the global absorption of heat. In fact, Southern Ocean heat uptake accounts for almost all the planet’s ocean warming, thereby controlling the rate of climate change.

This Southern Ocean warming and its associated impacts are effectively irreversible on human time scales, because it takes millennia for heat trapped deep in the ocean to be released back into the atmosphere.

…

So why is the Southern Ocean absorbing so much heat?

This largely comes down to the geographic set-up of the region, with strong westerly winds surrounding Antarctica exerting their influence over an ocean that’s uninterrupted by land masses.

This means the Southern Ocean winds blow over a vast distance, continuously bringing masses of cold water to the surface. The cold water is pushed northward, readily absorbing vast quantities of heat from the warmer atmosphere, before the excess heat is pumped into the ocean’s interior around 45-55°S (a latitude band just south of Tasmania, New Zealand, and the southern regions of South America).