Scientists have predicted that important ocean currents that redistribute heat, cold, and precipitation between the tropics and the northernmost parts of the Atlantic region will shut down around the year 2060 if current greenhouse gas emissions persist.
The new prediction, Published in the renowned scientific journal, Nature Communications and based on new calculations by researchers from the University of Copenhagen’s Niels Bohr Institute and Department of Mathematical Sciences contradicts the latest report from the IPCC which, based on climate model simulations, considers an abrupt change in the thermohaline circulation very unlikely during this century.
Using advanced statistical tools and ocean temperature data from the last 150 years, the researchers calculated that the ocean current, known as the Thermohaline Circulation or the Atlantic Meridional Overturning Circulation (AMOC), will collapse – with 95 percent certainty – between 2025 and 2095. This will most likely occur in 34 years, in 2057, and could result in major challenges, particularly warming in the tropics and increased storminess in the North Atlantic region.
“Shutting down the AMOC can have very serious consequences for Earth’s climate, for example, by changing how heat and precipitation are distributed globally,” said Professor Peter Ditlevsen from the Niels Bohr Institute. “While a cooling of Europe may seem less severe as the globe as a whole becomes warmer and heat waves occur more frequently, this shutdown will contribute to increased warming of the tropics, where rising temperatures have already given rise to challenging living conditions,”.
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Speaking further, he said “Our result underscores the importance of reducing global greenhouse gas emissions as soon as possible,”.
The researchers’ prediction is based on observations of early warning signals that ocean currents exhibit as they become unstable. These Early Warning Signals for the Thermohaline Circulation have been reported previously, but only now has the development of advanced statistical methods made it possible to predict just when a collapse will occur.
Among other things, the researchers analyzed sea surface temperatures in a specific area of the North Atlantic from 1870 to the present day. These sea surface temperatures are “fingerprints” testifying to the strength of the AMOC, which has only been measured directly for the past 15 years.
“Using new and improved statistical tools, we’ve made calculations that provide a more robust estimate of when a collapse of the Thermohaline Circulation is most likely to occur, something we had not been able to do before,” explains Professor Susanne Ditlevsen of UCPH’s Department of Mathematical Sciences.
Story was adapted from SciTech Daily.
