Great example of the global climate's complex system at work. The culprit here is a greenhouse-effect item called ozone. In the upper atmosphere, it reflects radiation in both directions, warming the earth by retaining heat, but preventing drastic consequences by reflecting UV rays from the sun. In the lower atmosphere, a number of complex chemical interactions occur, combine with local "hotspots" such as cities, or locations where the ozone layer is thin, to cause inversion inversion in the troposphere. This leads to waves in the upper troposphere, which invade the stratosphere. In the Northern Hemisphere, mountains force the waves toward the Arctic, displacing the polar vortex, then forcing warm air to the North Pole. North Pole temperature can increase rapidly.
The displaced polar vortex doesn't disappear; it shifts southward (the only direction there is at the North Pole), and suddenly it's 15 degrees Celsius at the North Pole, and negative 35 degrees Celsius in the immediate lower latitudes.
Ozone in the lower atmosphere comes from many sources. A major source is fossil fuel combustion, which creates some of the chemicals needed to form ozone, and creates heat (itself another source of ozone). Ozone is even created by photovoltaic cells, and it multiple chemicals-production processes. It is destroyed by other chemicals, many man-made, which rise into the stratosphere and deplete the ozone layer.
We've reduced stratospheric ozone depletion by phasing out several of rthe major man-made souces of depleting chemicals, but not all. Replacing fossil fuels with renewable energy sources will help, but the renewable energy sources themselves create both ozone, and ozone-creating conditions.
Reducing the production of tropospheric ozone, by eliminating fossil fuels, carries more urgency, in my opinion, than reducing CO2 output; others are free to disagree. Still, climate turbulence will be created by whatever is used to replace fossil fuels, until actual energy consumption can be reduced. Reducing total human energy consumption should have the greatest immediate beneficial effect, somewhat greater than limiting the sources of the energy. A combination of conversion to renewable energy, and reduction of total energy consumption, is needed. Long-term care for our atmosphere will require both.
