The current Atlantic system, which drives Northern Hemisphere climate, could be weakened by climate change, which could have serious consequences for global weather, including “extreme cold” in parts of Europe and North America and sea level rise in parts of the United States. State, according to a new scientific study.
The Atlantic Overturning (AMOC) circulation is part of a large ocean current system known as the Gulf Stream that carries warm water from the tropical north into the North Atlantic Ocean.
Niklas Bowers and author of the Potsdam Institute for Climate Impact Research Published Thursday.
As the atmosphere warms due to increased greenhouse gas emissions, the surface ocean below it holds more heat. Studies have shown that the potential for system collapse could have serious consequences for the global weather system.
The UK Meteorological Agency, or Meteorological Agency, has warned that a collapse of the AMOC will increase cooling in the northern hemisphere and contribute to rising sea levels in the Atlantic Ocean, decreasing overall precipitation across Europe and North America, and shifting the southern hemisphere monsoon. America and Africa. .
In April, the United Nations warned that the world was facing a climate crisis, and Secretary-General Antonio Guterres urged countries to “end the war against nature”.
Climate change has been blamed for the extreme weather that has hit the world in recent weeks and months, from deadly wildfires in Turkey and Greece to floods in many parts of Asia, including China, that have killed more than 300 people.
Climate models have already shown that AMOC is at its weakest state in more than 1,000 years.
However, it is not known whether this weakness is due to changes in the circulatory system or loss of stability.
The study, published in the journal Nature Climate Change, says the difference is significant.
By analyzing sea surface temperature and salinity patterns in the Atlantic Ocean, the study reveals that weakening in the last century may have been associated with loss of stability. Scientists say the world must do its best to keep emissions as low as possible.
“These results support the assessment that AMOC regression is not a simple oscillation or linear response to temperature rise, but may mean that the circulatory system approaches a critical threshold at which it can collapse,” said Bowers.
Other climate models have said that the AMOC will weaken over the next century, but it is unlikely that it will collapse before 2100.
A separate study published in the September 2021 issue of the journal Weather and Climate Extremes found that increases in extreme precipitation since 1996 have resulted in stronger and more frequent hurricanes due to human activity and greenhouse gases from the warm Atlantic Ocean.
Lead author Huanping said, “While our previous study showed that extreme rainfall in the northeast has increased dramatically over the past 25 years, this study is one of the first to show that this increase is in part due to human-induced climate change. ” he said. , a postdoctoral fellow at Dartmouth College, from the Department of Climate and Ecosystem Sciences at Lawrence Berkeley National Laboratory, said in an article on Phys.org:
“Our results show that decadal changes in Atlantic surface temperature, an important driver of Atlantic warming, along with anthropogenic greenhouse gases and aerosols, have contributed to the extreme increase in precipitation in the northeast since 1996,” Huang said.