références en Anglais

The idea that the AMOC is headed to collapse is very controversial, but it is clearly weakening. If the circulation did collapse, the consequences on both sides of the Atlantic Ocean would be immense—including large changes in temperature and a spike in weather-related disasters.

Disruption of the Atlantic Meridional Overturning Current could freeze Europe, scorch the tropics and increase sea level rise in the North Atlantic. The tipping point may be closer than predicted in the IPCC’s latest assessment.

The network of Atlantic ocean currents keeping the Earth's climate stable are far closer to collapse than first estimated, scientists warn.

The Atlantic Ocean's most vital ocean current is showing troubling signs of reaching a disastrous tipping point. Oceanographer Stefan Rahmstorf tells Live Science what the impacts could be.

The Atlantic Meridional Overturning Circulation is the main driver of northward heat transport in the Atlantic Ocean today, setting global climate patterns. Whether global warming has affected the strength of this overturning circulation over the past century is still debated: observational studies suggest that there has been persistent weakening since the mid-twentieth century, whereas climate models systematically simulate a stable circulation. Here, using Earth system and eddy-permitting coupled ocean–sea-ice models, we show that a freshening of the subarctic Atlantic Ocean and weakening of the overturning circulation increase the temperature and salinity of the South Atlantic on a decadal timescale through the propagation of Kelvin and Rossby waves. We also show that accounting for upper-end meltwater input in historical simulations significantly improves the data–model agreement on past changes in the Atlantic Meridional Overturning Circulation, yielding a slowdown of 0.46 sverdrups per decade since 1950

AMOC collapse would bring severe global climate repercussions, with Europe bearing the brunt of the consequences.

There is increasing concern that the Atlantic Meridional Overturning Circulation (AMOC) may collapse this century with a disrupting societal impact on large parts of the world. Preliminary estimates of the probability of such an AMOC collapse have so far been based on conceptual models and statistical analyses of proxy data. Here, we provide observationally based estimates of such probabilities from reanalysis data. We first identify optimal observation regions of an AMOC collapse from a recent global climate model simulation. Salinity data near the southern boundary of the Atlantic turn out to be optimal to provide estimates of the time of the AMOC collapse in this model. Based on the reanalysis products, we next determine probability density functions of the AMOC collapse time. The collapse time is estimated between 2037-2064 (10-90% CI) with a mean of 2050 and the probability of an AMOC collapse before the year 2050 is estimated to be 59±17%.

RealClimate: For various reasons I'm motivated to provide an update on my current thinking regarding the slowdown and tipping point of the Atlantic Meridional Overturning Circulation (AMOC). I attended a two-day AMOC session at the IUGG Conference the week before last, there's been interesting new papers, and in the light of that I have been changing

Collapse in system of currents that helps regulate global climate would be at such speed that adaptation would be impossible

Scientists now have a better understanding of the risks ahead and a new early warning signal to watch for.

A crucial system of ocean currents may already be on course to collapse, according to a new report, with alarming implications for sea level rise and global weather — leading temperatures to plunge dramatically in some regions and rise in others. Using exceptionally complex and expensive computing systems, scientists found a new way to detect an early warning signal for the collapse of these currents, according to the study published Friday in the journal Science Advances. And as the planet warms, there are already indications it is heading in this direction.

RealClimate: A new paper was published in Science Advances today. Its title says what it is about: "Physics-based early warning signal shows that AMOC is on tipping course." The study follows one by Danish colleagues which made headlines last July, likewise looking for early warning signals for approaching an AMOC tipping point (we discussed it here),

A collapse would bring catastrophic climate impacts but scientists disagree over the new analysis

The Atlantic meridional overturning circulation (AMOC) is a major tipping element in the climate system and a future collapse would have severe impacts on the climate in the North Atlantic region. In recent years weakening in circulation has been reported, but assessments by the Intergovernmental Panel on Climate Change (IPCC), based on the Climate Model Intercomparison Project (CMIP) model simulations suggest that a full collapse is unlikely within the 21st century. Tipping to an undesired state in the climate is, however, a growing concern with increasing greenhouse gas concentrations. Predictions based on observations rely on detecting early-warning signals, primarily an increase in variance (loss of resilience) and increased autocorrelation (critical slowing down), which have recently been reported for the AMOC. Here we provide statistical significance and data-driven estimators for the time of tipping. We estimate a collapse of the AMOC to occur around mid-century under the current scenario of future emi

Mexico and the Caribbean are experiencing the most intense heatwave in their recorded history. The Mexican Plateau is being seared by harsh dry heat, while the Caribbean contends with deadly humid temperatures. On June 12, 2023, the mercury soared above 45 °C (113 °F) in several areas, including regions of high altitude. The city of Torreón, sitting at 1 123 m (3 684 feet) above sea level, saw temperatures rise to 43.3 °C (109.94 °F) on June 12, while Durango Airport, located at 1 872 m (6 142 feet) altitude, experienced 40.4 °C (104.72 °F) heat. La Bufa, perched even higher at 2 612 m (8 570 feet) above sea level, broke all-time records with a temperature of 33.4 °C (92.12 °F).

The Gulf Stream has weakened substantially in the past decades, as revealed by the latest data and new studies. Weather in the United States and Europe depends strongly on this ocean current, so it’s important we understand the ongoing changes and what they mean for our weather now and in the near future.

An oil spill unleashed by Hurricane Ida is highlighting longstanding concerns about the more than 18,000 miles of decommissioned pipelines that still snake through the Gulf of Mexico, even though they no longer transport crude and natural gas.

The Gulf Stream has weakened substantially in the past decades, as new data and studies show. Weather in the United States and Europe depends strongly on this ocean current, so it’s important we understand the ongoing changes and what they will mean for our weather in the future.

The Atlantic Meridional Overturning Circulation (AMOC), a major ocean current system transporting warm surface waters toward the northern Atlantic, has been suggested to exhibit two distinct modes of operation. A collapse from the currently attained strong to the weak mode would have severe impacts on the global climate system and further multi-stable Earth system components. Observations and recently suggested fingerprints of AMOC variability indicate a gradual weakening during the last decades, but estimates of the critical transition point remain uncertain.

The Atlantic Ocean's current system, an engine of the Northern Hemsiphere's climate, could be weakening to such an extent that it could soon bring big changes to the world's weather, a scientific study said on Thursday.