‘Unprecedented’: Scientists declare ‘global climate emergency’ after jet stream crosses equator” screams the headline at Raw Story. Now here’s the hell freezes over part. The first post that shows up on Google accurately debunking this weather nonsense is by Anthony Watts, the well known “climate change skeptic”. The original source for the Raw Story article was a blog post by robertscribbler which was amplified in a youtube video by Paul Beckwith that is included in the Raw Story piece.
Climate scientists this week expressed alarm after “unprecedented” data showed the Northern Hemisphere Jet Stream crossing the Equator.
In a column on Tuesday, environmental blogger Robert Scribbler noted that the Northern Hemisphere Jet Stream had merged with the Southern Hemisphere Jet Stream.
“It’s the very picture of weather weirding due to climate change. Something that would absolutely not happen in a normal world,” he wrote. “Something, that if it continues, basically threatens seasonal integrity.”
This story is nonsense. The blogger robertscribbler is neither a meteorologist nor climatologist, nor is Paul Beckwith. I believe that robertscribbler’s expertise is in emergency management. He has excellent story telling skills and has built a large audience but he lacks scientific training. On the other hand, Joe Bastardi and Roy Spencer, who are quoted by Anthony Watts have decades of experience in meteorology. Watts, Bastardi and Spencer disagree with 97% of published climate scientists about climate change but they have studied the weather. It is embarrassing when “our side” is thoroughly debunked by Anthony Watts.
A “jet stream” in the usual sense of the word is caused by the thermal wind, which cannot exist at the equator because there is no Coriolis force. To the extent that there is cross-equator flow at jet stream levels, it is usually from air flowing out of deep convective rain systems. That outflow often enters the subtropical jet stream, which is part of the average Hadley Cell circulation.
There is frequently cross-equatorial flow at jet stream altitudes, and that flow can connect up with a subtropical jet stream. But it has always happened, and always will happen, with or without the help of humans. Sometimes the flows connect up with each other and make it look like a larger flow structure is causing the jet stream to flow from one hemisphere to the other, but it’s in no way unprecedented.
If robertscribbler and Paul Beckwith had paid attention to high level wind flow patterns near the extraordinary number of tropical storms in the Pacific in 2015 they would have seen many examples of high level winds crossing the equator. I am writing this post to show that “our side” has the integrity to correct our mistakes and admit our errors. I am also writing this as a warning to readers of Dailykos to make sure that your sources have expertise and demonstrated credibility in the subjects they cover. Even experts can make mistakes but this is what happens when non-scientists try to write about complex problems that they don’t understand.