Wednesday, May 13, 2020

Pandemic could make climate worse not better

Handily proving the old adage that every cloud has a lead lining, we now learn that recent joy at the clearer skies and reduced air pollution throughout the world, as industry and transportation slow dramatically during the coronavirus pandemic, should be tempered by the fact that the clearer air and improved air quality could lead to higher temperatures in an already warming world, and even to heavier monsoon rains.
With fewer particles and polluting gases to block its path, more sunlight will be able to reach the earth's surface, and greenhouse gases in the upper atmosphere will still block heat from dissipating back into space. The reduction in air pollution over northern India, which has seen its clearest skies in decades, may also have the effect of creating a more intense monsoon season.
All of this will happen relatively quickly compared to the gradual build-up of greenhouse gases over decades. On the other hand, the beneficial effect of reduced greenhouse gas production during the global slowdown is expected to be minimal. And, with most countries trying to re-open their economies as quickly as possible, we are likely to see a return to business-as-usual quite soon, so the coronavirus effect on greenhouse gases, while significant inthe short term, will probably be relatively shortlived and limited in its overall effect.
However, it is, of course, complicated. Climatologists caution that it will be very difficult to disentangle the climate effects of reduced air pollution from the random ups and downs of the weather due to various other reasons.

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