There are plenty of reasons to be concerned about the Earth's climate, from rising seas to droughts and intense heat waves. But amidst these concerns there is the potential for hyperbole, and we saw some of that flare up during the last few days, when two protagonists put forward the idea that the planet's jet streams are spinning out of control.

One of the people making this claim was Paul Beckwith, a self-described "well-known climate science educator," who noted that the jet stream in the Northern Hemisphere has crossed the equator and joined up with 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, declared that the jet stream was now wrecked. These claims went viral.

It sounds terrible, of course, and we definitely need to be concerned with rising levels of carbon dioxide and other greenhouse gases playing havoc with global atmospheric circulations. But in this case, we can probably view these claims as a bit of hot air.

The influential Capital Weather Gang, which forecasts conditions in Washington, DC and also writes about global weather issues, looked into the matter. After interviewing several scientists, the site declared the claim of a wrecked jet stream to be "utter nonsense." And for good reason—air flow between the hemispheres is not all that uncommon. 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 Ocean.

Some credible scientists have raised concerns about a warming planet destabilizing the polar jet streams, and there remains a vigorous debate in peer-reviewed journals about these ideas. But as one of the scientists who proposed the destabilization theory, Rutgers University's Jennifer Francis, told Capital Weather Gang, "I’d say cross-equator flow cannot be unprecedented, maybe not even all that unusual."