According to a new study, North Atlantic Ocean currents, which influence the number of severe storms and extreme temperatures that the United Kingdom experiences, have been more stable in recent decades than previously thought.
Image Credit: University of Reading.
A new study, examining early research and climate modeling, has disclosed patterns of weakening and strengthening of the Atlantic Meridional Overturning Circulation (AMOC). This is one of the world’s biggest climate mechanisms that underpin the Gulf Stream – over the past four decades. The modifications seem to be consistent with variability that would happen naturally.
The findings help to placate concerns raised in recent studies that the currents are deteriorating and possibly collapsing as a result of global warming. More summer heatwaves, bitterly cold winters and dangerous storms would batter Europe, as well as sea-level rise along the US east coast.
But the authors do warn that a decline of the AMOC over the 19th or 20th century cannot be excluded. This implies that action to avoid climate change deterioration remains imperative.
The consistent finding that these important North Atlantic Ocean currents have fluctuated naturally is significant as it could explain the worrying weakening that has been observed in recent decades.
Dr. Jon Robson, NCAS Climate Scientist, University of Reading
Robson added, “Although unlikely to be as dramatic as those seen in the film The Day After Tomorrow, the consequences of a further weakening would be a ramping up of extreme weather in the UK and Europe. The best course of action is to limit climate change as not doing so will undoubtedly lead to damaging alterations of weather and climate around the world in any scenario.”
The AMOC is a system of currents that sends warmer water from the tropics to the poles, and colder, denser water in the other direction at greater depth. The transport of heat to the North Atlantic keeps the climate in the United Kingdom warmer than in other locations at the same latitude.
The new study emphasizes that the AMOC has changed in strength over time and in various locations, along with sub-polar and sub-tropical stretches functioning on separate cycles.
The study has been published in the Nature Reviews Earth and Environment journal.
Furthermore, it offers proof that the currents reinforced between 1980 and 2000, which has possibly accentuated the recent decline that is noted by researchers.
It is expected that ongoing climate change will weaken the AMOC. Although our study didn’t detect a signal for long-term weakening, it is plausible that any change currently underway could be masked by the large variation between years and between decades. Any significant change would have a substantial effect on Europe’s weather and climate.
Dr. Laura Jackson, Study Lead Author, University of Reading
More research is needed, according to the authors, to improve AMOC monitoring and better distinguish ongoing changes from variations over years and decades.
The study also included GEOMAR (Germany), George Mason University (USA), IFremer (France), and NOC (UK).
Journal Reference:
Jackson, L. C., et al. (2022) The evolution of the North Atlantic Meridional Overturning Circulation since 1980. Nature Reviews Earth & Environment. doi.org/10.1038/s43017-022-00263-2.