
Winds in the 250mb level of the atmosphere, as seen on June 29.
earth.nullschool.net/modified by Ars
There are many reasons to be concerned about the Earth’s climate, from rising seas to droughts and intense heat waves. But amidst these concerns, there’s the potential for exaggeration, and we saw some of that flare up in recent days, as two key players raised the idea that the planet’s jet streams are spiraling out of control.
One of the people who made this claim was Paul Beckwith, a self-proclaimed “renowned climate science teacher,” who noted that the jet stream in the Northern Hemisphere has crossed the equator and joined the jet stream in the Southern Hemisphere. “Welcome to climate chaos,” Beckwith wrote. “We must declare a global climate emergency.” He then encouraged readers to donate to his site. Another person, Robert Scribbler, stated that the jet stream was now destroyed. These claims went viral.
It sounds awful, of course, and we should definitely be concerned about the rising levels of carbon dioxide and other greenhouse gases wreaking havoc on global atmospheric circulations. But in this case, we can probably consider these claims hot air.
The influential Capital Weather Gang, which forecasts conditions in Washington, D.C. and also writes about global weather issues, investigated the matter. After interviewing several scientists, the site declared the claim of a destroyed jet stream “utter nonsense”. And for good reason: the flow of air between the hemispheres is not that unusual. This cross-equatorial flow occurs at both the upper and lower levels of the atmosphere as part of the seasonal transition in the Western Pacific.
Some credible scientists have expressed concerns about a warming planet destabilizing the polar jet streams, and fierce debate continues in peer-reviewed journals about these ideas. But as one of the scientists who proposed the destabilization theory, Jennifer Francis of Rutgers University, told the Capital Weather Gang, “I’d say the flow across the equator can’t be unprecedented, maybe not even that unusual.”