The Southern Ocean is building up a colossal 'burp' that could reignite global warming, scientists warn

When it comes to the fight against climate change, the Southern Ocean is on our side.

For around 200 years it has acted as a major buffer against global warming by absorbing harmful carbon dioxide.

But the ocean around Antarctica is building up a colossal 'burp' that could trigger an increase in global temperatures, experts have warned.

And the effects could last for more than a century – with some of the world's most vulnerable countries at greatest risk.

Rather than a Homer Simpson–esque belch, this 'burp' signifies an 'abrupt discharge of heat' that could take place over decades.

Over time, deep currents bring warm water – which has gradually been heating up over centuries – to the surface of the ocean, where it directly reheats the atmosphere.

This would cause temperatures to increase, ice sheets to melt, sea levels to rise and reverse decades of climate change progress, the researchers cautioned.

And the impact could be comparable to global warming caused by humans, they said.

Climate researchers based in Germany predict that over the next 600 years, the Earth will begin to cool down thanks to a reduction in emissions and less reliance on fossil fuels.

But oceans can hold heat for a long time – leading to an enormous global energy imbalance over centuries.

This heat must eventually be re–released into the atmosphere, committing Earth to additional warming even once greenhouse gas emissions stop.

The study was carried out by a team at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany.

'After several hundred years of net–negative emissions and gradual global cooling, abrupt discharge of heat from the ocean leads to a global mean surface temperature increase of several tenths of degrees that lasts for more than a century,' the authors wrote in the journal AGU Advances.

'This ocean heat "burp" originates from heat that has previously accumulated under global warming in the deep Southern Ocean, and emerges to the ocean surface via deep convection.'

Their model predicts that in around 200 years, global warming will peak at around 2.25°C above pre–industrial levels.

It will then begin to decrease, dropping back down to below 1.5°C by the year 2600. But once the Southern Ocean releases its 'burp', global warming will once again rise to around 1.7°C – reversing centuries of progress.

The team found the warming would be 'greatest and longest-lasting in the Southern Hemisphere, suggesting a greater impact on today's more vulnerable countries of the global south'.

They predict that while the ocean will release heat during its 'burp', they do not believe it will also release large amounts of carbon dioxide.

This is good news, they said, as doing so would further amplify global warming.

Scientists have previously discovered the Southern Ocean bears the brunt of our planet's ocean warming, and accounts for almost all global ocean heat uptake.

This is despite it only covering around 15 per cent of Earth's total ocean surface area.

One significant ecological impact of strong Southern Ocean warming is on Antarctic krill. When ocean warming occurs beyond temperatures they can tolerate, the krill's habitat contracts and they move even farther south to cooler waters.

As krill is a key component of the food web, this will also change the distribution and population of larger predators and further increase stress for penguins and whales.