Antarctic Ocean Could Release Stored Heat in Century-Long ‘Burp’ Even With Emissions Removal
A massive release of heat from the Southern Ocean surrounding Antarctica – a phenomenon scientists are calling a “thermal burp” – is possible even as global efforts focus on removing carbon dioxide from the atmosphere,new research reveals. The delayed reaction to past emissions could temporarily offset cooling efforts and last for up to 100 years, according to a study published in Nature.
The Southern Ocean has absorbed over 90% of the extra heat trapped by greenhouse gas emissions,effectively slowing the rate of global warming. However, this absorption isn’t instantaneous. Deep ocean currents are only now beginning to carry that stored heat back to the surface, potentially leading to a significant, albeit temporary, rise in temperatures. This “burp” doesn’t negate the need to reduce emissions or actively remove carbon, but highlights the complex and frequently enough delayed responses within Earth’s climate system, and underscores the potential for unforeseen consequences even with aggressive climate action. Coastal communities, particularly those in the Southern Hemisphere, and sensitive Antarctic ecosystems are most vulnerable to the impacts of this potential thermal release.
Researchers used climate models to simulate the ocean’s response to both continued emissions and scenarios involving considerable carbon removal. They found that even with significant atmospheric carbon reduction, the delayed upwelling of heat from the deep Southern Ocean could cause a period of stalled or even reversed cooling. The study emphasizes the substantial uncertainty surrounding the Earth system’s response to negative emissions.
“There’s very large uncertainty in the Earth system response to net-negative emissions – we don’t understand that very well,” said Kirsten Zickfeld,a climate scientist at Simon Fraser University who studies these dynamics but wasn’t involved in the new paper. “We may well encounter surprises along the way, as this paper shows.”
The research team, led by Matthew Williams at the University of Wollongong, stresses that reducing fossil fuel use remains the most effective strategy. “Doing negative emissions and reducing our carbon load in the atmosphere is a good thing,” Williams said. “I would just add that, rather than do negative emissions, it’s better not to do the positive emissions in the first place.”
the study serves as a critical reminder that climate change is not a simple linear process, and that even prosperous mitigation efforts might potentially be accompanied by unexpected and prolonged consequences. Further research is needed to refine predictions and prepare for the potential impacts of this delayed thermal release.
