re: Trump: ‘Could the environmental insurrectionists explain what happened to global warming?’

quote:

---

Global warming is not causing more frequent cold air outbreaks in the mid-latitudes. If it were, that would show up in physical observations. And, I'll let you in on a little secret. It hasn't.

Sorry to bust your bubble, princess. ????

For decades, scientists said that global warming will reduce the frequency and severity of Arctic outbreaks. That was the consensus then. That's what was predicted. And, the reason for this, of course, is because of the First Law of Thermodynamics. To get a cold air outbreak requires a plentiful supply of frigid Arctic air. If the source region for that warms rapidly, then the supply of Arctic air depletes.

Turning up the thermostat in your home doesn't cause the room temperature to lower, does it?

This is very elementary stuff. I'm not quite sure what it is so hard for you to understand.

In Chapter 9 of their 2001 Third Assessment Report, the IPCC's said,



And, Table 9.6 directly above that text says that it is very likely that there'll be “fewer cold days and frost days over nearly all land areas” throughout the 21st century.

??LINK (p. 575)

And, that early hypothesis is in fact supported by the observational data of cold air outbreak frequency and severity in the mid-latitudes across the Northern Hemisphere. A recent paper, Oldenborgh et al. (2019), found that,



??LINK

This holds true in the Conterminous U.S. too, but even more interesting here is that record high maximums are also not increasing at the centennial scale, largely due to the extremely hot summers in the 1930s and 1950s. That isn't necessarily true, globally however, as hot maximums have increased in many regions.

??LINK (p. 55)

However, we still get quite a large number of cold air outbreaks and enough that laypeople have noticed a disconnect. After a string of years with very few cold air outbreaks, there all of a sudden was an increase in them following the winter of 2009-10, which then continued into 2014-15.

Some climatologists began to panic and scrambled to explain why this was happening so often when it theoretically shouldn't have been to that extent. They decided to come up with the (weakly supported) idea that Arctic amplification (the faster rate of warming in the Arctic region in comparison to the mid-latitudes) is causing the jet stream to “relax,” become wavier, and get locked into blocking configurations for longer periods of time, which then causes frigid air to spill southward into the mid-latitudes.

But as cute as this theory is, it isn't supported by the laws of fluid dynamics, much less observational data.

A greater meridional (north-to-south) temperature gradient (???/???) implies that there is stronger vertical wind shear (???/???), and therefore greater baroclinic instabilities which cause developing low-pressure systems to intensify. This, in turn, causes the Rossby wave pattern to tilt westward with height, forcing the jet stream to bend, becoming wavier.

This is given by the thermal wind relation and Eady growth rate (s):

???/??? = -(??/????) (???/???)

s = 0.3098 (??/??) |???/???|

The Eady growth rate says that the rate of baroclinic wave amplification depends on the vertical shear and static stability (??) in the troposphere. Thus, a smaller meridional thermal gradient (smaller ???) produces weaker shear, smaller s, and a less amplified trough-ridge pattern. In turn, this leads to fewer mid- or high-latitude blocking events, exactly opposite of your's and Grok's claim.

??LINK (pp. 51-70)

A paper published this year in AGU Advances, Chalif et al. (2025), found that,

”

---

Loading Twitter/X Embed...
If tweet fails to load, click here.