Scientists Debate AMOC Tipping Risk as Atlantic Current Carries 1 Petawatt of Heat North
Updated
Updated · bbc.co.uk · Jul 14
Scientists Debate AMOC Tipping Risk as Atlantic Current Carries 1 Petawatt of Heat North
3 articles · Updated · bbc.co.uk · Jul 14
Summary
Direct AMOC measurements only began in 2004, leaving scientists split over whether the Atlantic circulation is steadily weakening or edging toward a tipping point that could trigger a sharper shift.
Global warming is stressing the system by warming and freshening North Atlantic waters; less-dense water sinks less readily, weakening the overturning flow that helps keep the region salty enough to sustain itself.
Stefan Rahmstorf says cooling south of Greenland, falling salinity and other signals suggest the slowdown may already be underway, while Andrew Watson and recent Met Office work argue collapse this century looks unlikely even if weakening continues.
A weaker AMOC could still disrupt storm tracks, rainfall and winters in the UK and north-west Europe, while broader shifts could affect the West African monsoon, the Amazon and water and food supplies for hundreds of millions.
Evidence from the Younger Dryas nearly 13,000 years ago shows Atlantic circulation can reorganize abruptly, but the IPCC's 2021 assessment still judged an abrupt collapse before 2100 not expected.
How would a collapsing Atlantic current permanently redraw the global map of who can eat and where people can live?
As scientists warn of a tipping point, is the vital ocean data we need to predict it at risk from funding cuts?
With collapse odds now over 50%, are global societies prepared for the imminent and irreversible climate shock?
The Accelerating Threat of AMOC Collapse: Scientific Evidence, Global Consequences, and What Must Be Done
Overview
The Atlantic Meridional Overturning Circulation (AMOC) is a vital ocean current that regulates global climate by moving heat, salt, and freshwater, which in turn shapes weather patterns and sea levels. Recent research shows the AMOC is weakening faster than expected, partly because many models leave out the impact of Greenland’s meltwater. This extra freshwater disrupts the balance of salinity and temperature that drives the AMOC, making the threat even greater than previously thought. If the AMOC collapses, it could cause dramatic temperature drops in northern Europe and trigger far-reaching changes in the global climate system.