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Southern Ocean ‘Thermal Burp’
Southern Ocean ‘Thermal Burp’
What is a thermal burp?
- A thermal burp refers to the sudden release of long-stored heat from the deep ocean back into the atmosphere and surface waters.
- It is a climatic feedback mechanism where the ocean, after centuries of absorbing excess heat, overturns and expels this energy in a rapid pulse.
- The term is used to describe the abrupt nature of the release, unlike gradual warming trends.
How is it formed?
- Ocean layering: The Southern Ocean absorbs heat at depth while the surface becomes colder and saltier due to sea ice formation. Salt rejection during freezing makes the surface denser, while warmer water remains trapped below.
- Instability builds: Over centuries, this imbalance destabilises the water column.
- Deep convection event: Eventually, the stratification collapses, allowing deep, warm water to rise rapidly to the surface.
- Result: A sudden release of stored heat, comparable to current human-driven warming rates.
What are the major impacts of the release of heat burps?
- Renewed Warming: Even after global cooling begins due to net-negative emissions, a burp could reignite warming for 100+ years.
- Comparable to Human Activity: The rate of warming could match current anthropogenic warming levels.
- Regional Effects: Strongest in the Southern Hemisphere, disproportionately affecting global south nations.
- Climate Strategy Challenge: Undermines smooth temperature decline after carbon removal. Adds uncertainty to long-term climate planning.
- CO₂ Release: Some carbon may also be emitted, but the primary impact is thermal.
