From a recent story in the MIT Technology Review, focusing on carbon emissions in the West Coast of the United States:
Together, California, Idaho, Oregon, and Washington saw fossil-fuel emissions decline by around 69 million tons of carbon dioxide last year as the pandemic slashed pollution from ground transportation, aviation, and industry, according to data from Carbon Monitor. But from July 1 to July 25, fires in those states produced about 41 million tons of carbon dioxide, based on data provided to MIT Technology Review from the European Commission's Copernicus Atmosphere Monitoring Service.
That's far above normal levels for this part of the year and comes on top of the surge of emissions from the massive fires across the American West in 2020. California fires alone produced more than 100 million tons of carbon dioxide last year, which was already enough to more than cancel out the broader region's annual emissions declines.
The Washington Post published a similar story of shattered hope for the climate, based in Australia:
The 2019-2020 Australian wildfire season resulted in 0.1 degrees Fahrenheit of cooling by mid-2020. The cooling, however, was tacked atop a continued net warming of the climate and had a negligible effect on slowing the pace of human-induced climate change from fossil fuel burning.
Covid-19 sparked a marked drop-off in travel, manufacturing and commerce that peaked in March of 2020. While that meant a lesser emission of greenhouse gases, which warm the climate, cleaner air in places like Asia yielded a reduction in areal coverage of smog and haze. That comparative absence of smog, which ordinarily reflects some sunlight back into space, may have produced a warming influence. … Overall, the National Center for Atmospheric Research team [in Boulder, CO] thinks that 0.09 degrees of warming may have resulted globally from the covid-19 shutdowns.
So, I suppose the positive takeaways from this are: that it's not too late to reverse some damage from climate change!…by enacting large-scale, long-term changes to the way our society functions. Also, geoengineering can really make a difference!…which means that maybe our best hope for long-term planetary survival is literally blocking out the sun with reflective clouds. Of course, just because incidental solar geoengineering in a tropical location produced a slight cooling effect, that doesn't mean it's necessarily a good thing overall for the planet, as MIT News noted last year:
Scientists at MIT have found that solar geoengineering would significantly change extratropical storm tracks — the zones in the middle and high latitudes where storms form year-round and are steered by the jet stream across the oceans and land. Extratropical storm tracks give rise to extratropical cyclones, and not their tropical cousins, hurricanes. The strength of extratropical storm tracks determines the severity and frequency of storms such as nor'easters in the United States.
The team considered an idealized scenario in which solar radiation was reflected enough to offset the warming that would occur if carbon dioxide were to quadruple in concentration. In a number of global climate models under this scenario, the strength of storm tracks in both the northern and southern hemispheres weakened significantly in response.
Weakened storm tracks would mean less powerful winter storms, but the team cautions that weaker storm tracks also lead to stagnant conditions, particularly in summer, and less wind to clear away air pollution. Changes in winds could also affect the circulation of ocean waters and, in turn, the stability of ice sheets.
Ah, foiled again.
The pandemic slashed the West Coast's emissions. Wildfires already reversed it. [James Temple / MIT Technology Review]
Australian fires had bigger impact on climate than covid-19 lockdowns in 2020 [Matthew Cappucci / The Washington Post]
Image: DoD photo by Master Sgt. Christopher DeWitt, U.S. Air Force [Public Domain]