The Northern Hemisphere jet stream — that high-altitude wave of winds separating cold from warm air — has crossed the equator and joined the Southern Hemisphere jet stream, claim two bloggers recently. With warnings of the jet stream being “wrecked” and therefore an international climate emergency, is there actually a need to panic?
Robert Scribbler — an “emerging threats expert” in his words — and Paul Beckwith, currently working on his PhD at University of Ottawa in Canada and has a particular interest in “abrupt climate system change,” are the two personalities who issued the warnings.
Their claims have become viral and been picked up by Reddit and a number of websites.
Destabilized Jet Stream?
Scribbler pointed to the cross-equator flow as a sign of man-made climate change, anchored on the belief that disproportionate Arctic heating is causing the jet stream to destabilize.
“[A]s the Poles have warmed due to human-forced climate change, the Polar Jet Streams have moved out of the Middle Latitudes more and more,” he wrote in a blog post on June 28. They are said to have increasingly invaded regions within the polar zone and the tropics, linking broadening latitudinal zones.
Scribbler said that the traditional dividing lines are getting weak, with flows of upper level air between the hemispheres now exchanged to a higher degree.
Beckwith, on the other hand, warned the jet stream activity is never before seen and indicates global mayhem, with the climate system behaving in novel, scary ways. Citing a chaotic climate situation, he urged declaring a global climate emergency.
Jet streams come in two forms: polar and subtropical. The hemispheres have one of each. These streams are produced by atmospheric heating via solar radiation and stay in place through the force of inertia.
No Mayhem Ensues
In a commentary, The Washington Post questioned the validity of the “shrill” claims, explaining that air flow detected between hemispheres take place periodically. The claims are believed to be neither supported nor scientific, and hail from non-experts “misleading” the public.
Air flow between the Northern and Southern hemispheres is hardly uncommon, confirmed a number of atmospheric scientists that Post reached out to.
Meteorology professor Cliff Mass asserted that the flow usually crosses the equator, calling the claims “total nonsense.” The cross-equator flow that the bloggers identified does not lie between mid-latitude jet streams, he added.
Senior meteorologist Ryan Maue disagreed with the thinking that cross-equator flow is proof of a combined jet stream of the hemispheres. This flow at upper and lower levels is a regular feature of the Western Pacific monsoon through boreal summer, he said.
While a legitimate concern, global warming having a hand in the destabilization of the polar jet stream remains a controversial idea. Its proponent, Rutgers University meteorology professor Jennifer Francis, suggested that the hypothesis may have been misappropriated by the two bloggers — cross-equatorial flow likely cannot be considered rare or unprecedented.
On the morning of July 1, Scribbler updated his blog post to respond to criticism of his claims.