This slowdown threatens marine biodiversity and risks accelerating global warming.
The slowing of deep ocean currents, caused by the melting ice of Antarctica, is coming sooner than expected. According to a new study published Thursday, May 25 in the journal Nature Climate Change, it occurs decades “ahead of schedule”threatening marine life and threatening to accelerate global warming.
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Scientists have long warned that an acceleration in the melting of Antarctic ice and rising temperatures, driven by the emission of human-made greenhouse gases, is expected to have a significant effect on the global grid. ocean currents that carry nutrients, oxygen and carbon.
“The impacts of climate change are ahead”
An earlier study, using computer models, had suggested that water circulation in the deepest parts of the oceans would slow by 40% by 2050 if emissions remained high. But this new study, based largely on observational data collected by hundreds of scientists over decades, shows that this process actually already slowed by 30% between the 1990s and 2010s.
“Our data shows that the impacts of climate change are ahead of schedule,” said lead author Kathryn Gunn, from Australia’s science agency CSIRO and Britain’s University of Southampton. “In a way, the fact that this is happening is not surprising. But the timing is” more, underlined the scientist.
The implications could be significant, with the deep ocean of Antarctica acting as a key “pump” for the global network of ocean currents. “When ocean circulation slows, more carbon dioxide and heat remain in the atmosphere, which accelerates global warming”, explained Kathryn Gunn to AFP. The oceans are a crucial climate regulator absorbing large amounts of the additional carbon that humans have released into the atmosphere since the mid-1800s, as well as more than 90% of the increase in Earth’s heat.