The United States is in a deep freeze while most of the world is very warm? Once again, it’s climate change – Lowell Sun
FILE – A worker pauses while clearing snow from Highmark Stadium in Orchard Park, New York, Jan. 14, 2024. While the United States is shivering in the bitter cold, most of the rest of the world is feeling unseasonably warm weather. This fits with what climate change is doing to the Earth, scientists say Tuesday, January 16. (AP Photo/Jeffrey T. Barnes, File)
By Seth Borenstein (AP Science Writer)
Much of the United States is shivering from the bitter cold while most of the rest of the world is experiencing unseasonably warm weather. Although strange, this discrepancy fits comfortably into explanations of what climate change is doing to Earth, the scientists said.
In a map of global temperatures over the past few days, large parts of the world — the Arctic, Asia, parts of Africa, the Middle East, and South America — appear in dark red, indicating more than twelve degrees Fahrenheit (7 degrees Celsius). Warmer than the late 20th century average. But the United States sticks out like a cold thumb — dark purple-bluish, out of control but on the icy side.
Wind chills in parts of North Dakota reached 70 degrees below zero (minus 56 degrees Celsius), while the heat index in Miami was more than 160 degrees warmer at 92 (minus 33 degrees Celsius). The fourth-coldest NFL football match was held in Kansas City, while the worldwide thermometer reached 92 degrees, 12 degrees (6.8 C) warmer than average on Friday during the Australian Open tennis tournament in Melbourne. Warm temperatures fell overnight in Aruba, Curacao, parts of Argentina, Oman and Iran.
Where the weather was warmer than usual, it occurred in the Southern Hemisphere, which is summer, and in the Northern Hemisphere, which is winter. For example, Oman, in the north, experienced its warmest January night on record with a temperature of 79.5 degrees (26.4 degrees Celsius). Argentina, in the south, set a record for the warmest night in January, reaching 81.1 F (27.3 C).
If it seems as if the world has turned upside down, somehow it has. Because all of this comes from what’s happening in the Arctic, which has been warming twice as fast as the rest of the planet. Now, it’s heating up three to four times faster.
“When the Arctic is unusually warm (as it is now), we are likely to see an extreme cold invasion that places like Texas are ill-equipped to deal with,” said Jennifer Francis, a climate scientist at the Woodwell Research Center. He pioneered the Arctic Amplification Theory, which links cold outbreaks to climate change. “Rapid warming in the Arctic is one of the clearest symptoms of human-caused climate change, making extreme winter events more likely even as the overall global temperature rises.”
The way the cold invades is through a weather phrase that has become increasingly familiar to Americans: the polar vortex. It’s a weather term that dates back to 1853, but has only been used frequently in the past decade or so.
That may be because ice stabs occur more often, said Judah Cohen, a winter weather expert from Atmospheric Environmental Research, a commercial firm outside Boston.
Cohen said that the polar vortex is a strong icy weather that usually remains above the upper part of the planet, confined by the strong winds that blow around it.
He said it looked like an ice skater spinning fast with her arms folded inward. But when the polar vortex weakens, the arms begin to fly, the skier slides and “all the cold air is released away from the center of the polar vortex,” Cohen said.
Cohen said the current cold outbreak is consistent with the shifting Arctic and the polar vortex. “What we found is that when the polar vortex stretches like a rubber band, severe winter weather is much more likely in the United States. This is where things tend to focus, and in January we have an extreme case of polar vortex stretching.
This is stronger and may last longer than most people, Cohen said.
Cohen and others have conducted studies showing that polar vortex outbreaks have become more frequent in recent decades.
The idea is that the jet stream — the upper air circulation that drives the weather — is more wavy in the amplified greenhouse effect, said Steve Vavrus, a climate scientist at the University of Wisconsin-Madison. Cohen said that these wave changes in the upper air push the polar vortex out of its place and head toward the United States.
It’s a theory that’s still debated by climate scientists but is becoming increasingly accepted. Initially, Vavrus and Francis hypothesized that this was due to melting Arctic sea ice leading to changes in atmospheric pressure. Now many scientists say it’s more complex, but it’s still linked to climate change and extreme warming in the Arctic, with other factors like Siberian snow cover and other weather waves also playing a role.
“The main takeaway for me now is that Arctic amplification occurs and has complex interactions within our climate system. Winter will always bring us cold weather, but like the warm season, it may change the ways we understand it and the ways we still We learn about it.” “Contrary to the Vegas slogan, what happens in the North Pole doesn’t stay in the North Pole.”
“Think about what happens when a single symphony orchestra plays,” said Victor Gensini, a professor of meteorology at Northern Illinois University. “What drives all those orchestral instruments is a warming planet.”
Gensini and Cohen said that this cold wave in the United States will fade within several days and be replaced by unusually warm weather, due to climate change. But it seems that another polar vortex will come at the end of the month, although it will not be as strong as this one.
Despite the American cold, the Earth’s average global temperature continues to set daily, weekly and monthly records, as it has for more than seven months. Scientists said this is because the area of the United States represents only 2% of the Earth’s surface.
“Someplace like Chicago or Denver or Lincoln, Omaha, Oklahoma City, Dallas, Houston, I mean we all experience it,” said Gensini, who said the temperature outside his window Tuesday was minus 6 degrees. “We are one isolated enclave if you look globally.”
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