July 27, 2023
Scientists have warned revealed that the crucial system of ocean currents responsible for transporting heat across the North Atlantic could be on the brink of collapse, according to a new study.
The Atlantic meridional overturning circulation, a vital part of the Earth's climate system, has been slowing down since the mid-1900s. However, the latest research suggests that this slowdown could escalate, potentially leading to catastrophic consequences including sea-level rise and extreme weather events.
Peter and Susanne Ditlevsen, researchers from Denmark, conducted an analysis of sea surface temperatures in the North Atlantic from 1870 to 2020. Their findings indicate that the collapse of the ocean currents might occur as soon as 2025 in a worst-case scenario, or by 2095, given the current trajectory of greenhouse gas emissions.
The prediction starkly contrasts with the 2021 estimate by the United Nations Intergovernmental Panel on Climate Change, which had suggested that such a collapse was unlikely to happen this century.
Julio Friedmann, Chief Scientist at Carbon Direct, stressed the importance of taking action to address this alarming possibility. He said, "There are large uncertainties in this study, in many prior studies, and in climate impact assessment overall, and scientists sometimes miss important aspects that can lead to both over and underprediction of impacts. Still, the conclusion is obvious: Action must be swift and profound to counter major climate risks."
Stefan Rahmstorf, co-author of a 2018 study on the subject, provided further insight into the situation. While acknowledging the uncertainty surrounding the tipping point for the collapse, he expressed concern about the conservative nature of the IPCC estimate. He said, "Increasingly the evidence points to the risk being far greater than 10% during this century... rather worrying for the next few decades."
If the Atlantic meridional overturning circulation were to collapse, it could have devastating consequences on a global scale. Extreme weather events would become more frequent and severe in the Northern Hemisphere, and the East Coast of the United States could face rising sea levels. Additionally, millions of people in southern Africa might be impacted by prolonged droughts.
The urgency to address climate change and curb greenhouse gas emissions cannot be overstated. As the world grapples with the potential repercussions of a collapsing ocean heat transport system, scientists and policymakers alike are highlighting the need for immediate and comprehensive action to mitigate the risks and safeguard the planet's future.