GabyDanish scientists have delivered a somewhat paradoxical forecast regarding humanity’s ongoing reliance on energy sources that emit greenhouse gases. Experts warn that critical ocean currents, which transport heat, cold, and precipitation between the tropics and remote areas of the Atlantic, could completely shut down by around 2060 if greenhouse gas emissions continue at their current pace. This latest calculation contradicts previous reports from the Intergovernmental Panel on Climate Change (IPCC).
As Europe braces for the impacts of climate change, one might envision a future marked by extreme heat. However, a recent study by Danish researchers paints a starkly different picture: experts predict that the Atlantic Meridional Overturning Current (AMOC)—a system of ocean currents that regulates the distribution of heat and cold between the North Atlantic and the tropics—could cease to function entirely if greenhouse gas emissions are not reduced. The researchers employed complex statistical tools to analyze ocean temperature data from the past century and a half. They determined with 95% confidence that the AMOC system could vanish sometime between 2025 and 2095, with the most likely timeframe for this dramatic event being 2057.
The shutdown of the AMOC ocean current system would create significant challenges, ranging from intensified warming in the tropics to an increase in storm activity in the North Atlantic region. Professor Peter Ditlevsen notes that this could have very serious consequences for the Earth’s climate. For instance, the halt of thermohaline circulation would alter the way heat and precipitation are distributed globally. While cooling in Europe might seem less severe as the planet warms overall and heatwaves become more frequent, the disappearance of the AMOC would exacerbate warming in the tropics, where rising temperatures have already led to challenging living conditions.
According to Mr. Ditlevsen, the findings of their study underscore the urgent need to mitigate global warming by reducing greenhouse gas emissions worldwide. However, the calculations from Danish scientists cast doubt on the conclusions of the latest IPCC report, which suggests that a sudden change in thermohaline circulation is unlikely this century, as indicated by climate modeling. The researchers based their predictions on early warning signals emitted by ocean currents when they begin to destabilize, signals that have been reported previously. Yet, it is the recent advancements in statistical methods that have finally allowed for a precise prediction of the potential collapse timeline.
The researchers focused on sea surface temperatures in a specific region of the North Atlantic from 1870 to the present. This approach enabled them to determine that these temperature fluctuations are “fingerprints” of the AMOC’s strength, which has only been directly measured over the past 15 years. Professor Susanne Ditlevsen explained that by utilizing new and refined statistical tools, they were able to make calculations that provide a more reliable estimate. This is why scientists now have a clearer understanding of when the collapse of thermohaline circulation is most likely to occur, something that was previously impossible.
The AMOC ocean current system has remained in its current state since the last ice age, during which it collapsed. This collapse, known as the Dansgaard-Oeschger event, was observed in ice cores from the Greenland ice sheet and occurred 25 times due to climate changes during the ice age. As noted by Earth, these events were accompanied by extreme climate changes, with temperatures fluctuating by 10-15 degrees over a span of just 10 years. In contrast, today’s climate change is characterized by a warming of 1.5 degrees over a century. With the threat of another such collapse looming, the urgency of mitigating greenhouse gas emissions becomes even more critical.
