Heat trapped in the Southern Ocean could be “burped” up into the atmosphere and cause climate change-like effects even after humans stop greenhouse gas emissions, according to a study published in the journal AGU Advances. This 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”, said the study. As a result, there could be a “renewed pulse of warming from the maritime zone, without any new CO2 entering the atmosphere”, said news site Daily Galaxy.
The study showed that this release would occur “after several centuries of net negative emissions levels and gradual global cooling”, and could lead to a “decadal- to centennial-scale period of warming”, said science site Eos. This warming would be “comparable to average historical anthropogenic warming rates”. The released heat will not be distributed evenly around the world; the effects will be “greatest and longest-lasting in the Southern Hemisphere, suggesting a greater impact on today’s more vulnerable countries of the global south”, said the study. But “while some CO2 is released, the primary impact is thermal, not chemical”, said Daily Galaxy.
The burp is attributed to two processes: warmer surface waters are mixing with cooler layers and ventilating heat into the depths, plus the “ocean’s natural heat release pathways” are becoming less active, according to Daily Galaxy. These “combined effects trap heat where it cannot easily escape, setting the stage for a delayed warming rebound”.
The study shows that “burning fossil fuels with reckless abandon for centuries will have lasting impacts long after the green revolution finally takes hold”, said Popular Mechanics. But the “sooner we can achieve this technological dream, the better our chances are for preserving a future”. |