Amid debates about the reality of Global Warming and Climate Change, the new study has claimed that global warming is going to play a crucial role in the world’s climate. Further, the ocean currents are losing strength that usually plays a vital role in climate change. Recently, two separately published studies in the journal Nature have shown powerful evidence indicating that the system of ocean currents known as the Atlantic Meridional Overturning Circulation or Amoc is losing strength.
Lead author of one study David Thornalley of University College London has said that since the mid-19th century, Amoc strength has declined by 15 percent. Currently, it is weakest for at least 1,500 years. Further added that probably since the end of the last big Ice Age 11,500 years ago. The study further suggests that the influence on Europe and the US east coast would be serious in case the weakening continues. This could eventually result in more outbursts of extremely cold air from the Arctic and would also de-stabilize the winter weather. The study also indicates the impact on the summer. It is suggested that due to weak Amoc, African rainfall would push towards southward, thus increasing the risk of drought in the Sahel. Dr. Thornalley, further said that their work concluded that most of the climate models are underestimating the chance of abrupt changes.
Amoc carries water from the tropics north-west in the Gulf Stream to temperate and polar regions. It is a powerful heat transport system which releases its energy when it reaches to the Polar Regions. Due to the warmer climate, the Arctic and Greenland ice are melting, resulting in the release of fresh water into the Atlantic at high latitudes, thus weakening Amoc and making water less dense.
Another recently published study by scientists at the Potsdam Institute for Climate Impact Research suggested that Amoc weakening is more rapidly since 1950 in response to recent global warming. While conducting research, they used climate model data and confirmed that sea surface temperature patterns are a good indicator of Amoc’s strength. Lead author Levke Caesar said that their team detected a specific pattern of ocean cooling south of Greenland and unusual warming off the US coast. They further explained this as Amoc slows down, less heat is transported to the northern Atlantic. This is the only ocean region which is still cool in pretext to global warming. On the contrary, sea temperatures off the US east coast have risen exceptionally fast.
Summer Praetorius of the US Geological Survey quoted that the present two studies converge on the conclusion that the modern Amoc is in a relatively weak state.