Warmer Arctic led to ‘killer cold’ in Texas
NEW YORK, Sept 4, (AP): Warming of the Arctic caused by climate change has increased the number of polar vortex outbreaks, when frigid air from the far north bathes the central and eastern United States in killer cold, a study finds.
The study in the journal Science Thursday is the first to show the connections between changes in the polar region and February’s Valentine’s Week freeze that triggered widespread power outages in Texas, killing more than 170 people and causing at least $20 billion in damage.
The polar vortex normally keeps icy air trapped in the Arctic. But warmer air weakens the vortex, allowing it to stretch and wander south. The number of times it has weakened per year has more than doubled since the early 1980s, said study lead author Judah Cohen, a winter storm expert for Atmospheric Environmental Research, a commercial firm outside of Boston.
“It is counterintuitive that a rapidly warming Arctic can lead to an increase in extreme cold in a place as far south as Texas, but the lesson from our analysis is to expect the unexpected with climate change,” Cohen said.
Climate scientists are still debating how and whether global warming is affecting cold snaps — they know it’s reducing the overall number of cold days, but they are still trying to understand if it leads to deeper cold snaps.
Cohen’s study is the first to use measurements of changes in the atmosphere to help explain a phenomenon that climate models had struggled to account for.
Cohen’s study “provides a potentially simpler interpretation of what’s going on,” said Pennsylvania State University climate scientist Michael Mann, who wasn’t part of the study.
Cohen was able to show how there have been dramatic differences in warming inside the Arctic itself, which drives how the polar vortex can stretch and weaken.
Research
When the area north of England and around Scandinavia warms more than the area around Siberia, it stretches the polar vortex eastward and the cold air moves from Siberia north over the polar region and then south into the central and eastern part of the United States.
“The Texas cold blast of February 2021 is a poster child” for the link between a changing Arctic and cold blasts in lower latitudes, said climate scientist Jennifer Francis of the Woodwell Climate Research Center on Cape Cod. She helped pioneer the Arctic link theory, but wasn’t part of Cohen’s research. “The study takes this controversial hypothesized linkage and moves it solidly toward accepted science,” she said.
Europe’s southernmost glaciers will likely be reduced to ice patches in the next two decades due to climate change, as the shrinking of ice mass on the Pyrenees mountain range continues at the steady but rapid speed seen at least since the 1980s, Spanish scientists say in a new study.
The Pyrenees, marking the natural border between Spain and France, saw three glaciers disappear or become reduced to stagnant strips of ice since 2011. In 17 of the two dozen remaining ice sheets, there’s been an average loss of 6.3 meters (20 feet) of ice thickness.
Their mass also shrank over one-fifth on average, or 23%, in nearly one decade, according to the study published last week in the peer-reviewed Geophysical Research Letters. Its findings were announced to the media on Friday.
The Spanish scientists blamed climate change for the retreat, and in particular a 1.5-degree-Celsius (2.7 Fahrenheit) overall temperature increase in the Pyrenean region since the 19th century.
“What we are seeing here is an advance warning of what may happen in other mountains, like in the Alps,” said Jesús Revuelto, one of the study’s authors. “Their glaciers have much more mass and entity, but we are showing them the way.”
Geologist Ixeia Vidaller, another leading author, said that the loss of ice mass was also a “tragedy” for the Pyrenean landscape, with yet-to-be-seen effects on biodiversity.
The researchers work for the Pyrenean Institue of Ecology, or IPE, a branch of Spain’s main public scientific research body, the CSIC. They used high-resolution satellite imagery and visuals obtained by research flights in 2011 to map the ice mass evolution, comparing it with data obtained in field visits and 3D models of the mountain ridges produced last summer with the help of drones.
The scientists found a loss of up to 20 meters (66 feet) of ice thickness in parts of some of the fastest-melting glaciers. The diminishing of the four largest of them is more consistent than that of the smaller-sized among the studied ice sheets, they said, as the ice in many cases has already retreated to the shade of ridges carved by centuries of erosion.
Comparing to other existing studies about past ice loss, IPE’s research also found that the annual rate of ice mass loss has not slowed down since the 1980s.
“We can argue with confidence that Pyrenean glaciers are in extreme jeopardy and could disappear or become residual ice patches in about two decades,” the scientists wrote.
A recent major report by scientists for the United Nations calls climate change clearly human-caused, “unequivocal” and “an established fact.” It also says that temperatures in about a decade will probably blow past a level of warming that world leaders have sought to prevent.
The Mediterranean basin, shared by southern Europe, the Middle East and northern Africa, is being identified by U.N. experts as a “climate change hot spot,” likely to endure devastating heat waves, water shortages and loss of biodiversity, among other consequences.
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NICOSIA, Cyprus: Meteorologists in Cyprus said Friday that August was the east Mediterranean island’s hottest month since the recording of temperatures began 38 years ago.
The Meteorological Department of Cyprus said the average high temperature last month was 39.8 degrees Celsius (103.6 F), eclipsing the previous record of 39.7 degrees Celsius (103.5 F) that was set in July 2020.
The average August daytime high between 1981-2010 was 37 degrees Celsius (98.6 Fahrenheit).
The highest temperature recorded last month was 44.3 degrees Celsius (111.74 Fahrenheit), the third-hottest recorded for an August since 1983.
US weather officials previously announced that July was the hottest month on Earth in 142 years of recordkeeping, .
In July, Cyprus suffered what authorities called it’s “most destructive wildfire” in many decades. It killed four people, scorched more than 50 square kilometers (20 square miles) of forest and orchards and destroyed dozens of homes.
Although there has been no scientific study linking climate change to the increasing frequency of large wildfires in Cyprus, Environment Minister Costas Kadis said last month that empirical evidence shows this to be the case.
Kadis said the east Mediterranean is now considered a “global climate change hot spot” with biodiversity and forest ecosystems that are “intensely negatively impacted.”