Why climate change could make some places colder – Yahoo News
As much of the Northern Hemisphere continues to bake in a year of unprecedented heat waves linked to climate change, one paradoxical consequence of rising global temperatures is that some areas of the world could become much colder.
A study published this month by researchers at the Potsdam Institute for Climate Impact Research found that the Atlantic meridional overturning circulation (AMOC) current system could be on the verge of collapse. The conveyor belt system transports warm surface ocean water from the tropics, up along the coast of Florida to the northern Atlantic Ocean. Colder water sinks and is moved along the ocean floor to the south, helping to regulate the global climate.
“That’s one of the reasons that the climate in Europe is so pleasant,” Harold Wanless, professor of geography and urban sustainability at the University of Miami, told Yahoo News. “You go to the same latitude over in Newfoundland and Labrador, it’s pretty harsh in the winter.”
The system’s collapse, which researchers have concluded is in part caused by the melting of Arctic ice, could result in the dramatic cooling of parts of Europe and North America. But the extreme cold in those locations would not be the only change. The current system is also responsible for the wind that propels storms that cross the Atlantic, which in turn helps regulate sea levels.
“The Gulf Stream flowing north from the tropics, if that slows down, that north-flowing current piles up water to the right side. Bimini [in the Bahamas], for instance, is about a meter higher [in terms of sea level] than in Miami because of the north-flowing current,” Wanless said. “If that slows down or stops, that will cause almost a meter of rise here.”
The shutting down of the current would also mean that warm water in the middle latitudes would get even warmer, potentially giving rise to more tropical storms and hurricanes. In fact, the AMOC helps regulate weather patterns across the world.
“It’s one of those events that should not happen, and we should try all that we can to reduce greenhouse gas emissions as quickly as possible,” Niklas Boers, the lead author of the study, told the Washington Post. “This is a system we don’t want to mess with.”
While scientists are attempting to confirm the study’s findings, ample research has shown that climate change is already wreaking havoc with the jet stream, the river of wind circling the globe driven by temperature differences between latitudes. With the Arctic warming faster than any other place on Earth, the temperature differential between latitudes has become less pronounced, destabilizing the jet stream.
As a result, polar vortex events like the one that crippled the Texas power grid this winter become more likely.
While climate change skeptics like Sen. James Inhofe, R-Okla., have pointed to the continued existence of cold weather as a sign that global warming is a threat that humanity need not take seriously, more and more research is emerging detailing the myriad ways in which the buildup of greenhouse gases in the atmosphere will affect the climate.
As the latest report from the United Nations Intergovernmental Panel on Climate Change makes clear, while the planet has so far seen an average temperature rise of 1.2 degrees Celsius and will continue to warm unless dramatic actions are taken to curb greenhouse gases, how that warming plays out will depend on different factors.
“With further global warming, every region is projected to increasingly experience concurrent and multiple changes in climatic impact-drivers,” the report states.
What is clear now is that the number of record high temperatures being set around the world continues to outpace the number of record lows by a ratio of 2:1. Computer models have shown that that disparity will grow to 20:1 by 2050 and to 50:1 by 2100.
While many Americans have already begun scouting out new places to live so as to avoid the ravages of climate change, the truth is that making an educated guess is more complex than many people yet imagine.
Factoring in the possibility of the collapse of the AMOC current or gaming out the fluctuations of the jet stream adds even more complexity.
“It means things have gotten really out of control,” Wanless said.
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