COVID-19 Brought Cleaner Air, But Crowded Streams
Fishing became a popular way for people to escape the house during the coronavirus quarantine. Brett Prettyman/Trout Unlimited.
By Jim Wilson, for Trout Unlimited
I live in a land without trout streams, so fishing locally during the first two months of the coronavirus pandemic meant no trout fishing. COVID-19 related closures kept me off the streams until mid-May.
The first time I headed out the free-flow driving conditions around the Washington, D.C., and Baltimore beltways was kind of shocking. Unfortunately, I wasn’t the only one thinking of fishing. As I approached my destination it became clear everyone else had the same idea — the parking lots along the Gunpowder River were full.
The pleasant urban travel experience and clear blue skies I encountered lead me to wonder how much air pollution and greenhouse gas emissions were changing during the quarantine. Drawing from my own expertise as an environmental consultant, I did a little research to figure out how the quarantine changed things.
For perspective, before the COVID-19 pandemic of 2020, emissions of carbon dioxide (CO2) were rising globally by about 1 percent per year for the last 10 years, with no growth during 2019. Renewable energy production was expanding, but because much of the renewable energy was being deployed alongside fossil energy, it did not replace it.
Government stay-at-home orders and various international border closures during the first months of the pandemic drastically altered energy demand and reduced travel around the world. A recent paper in Nature Climate Change estimates that daily global CO2 emissions decreased by 17 percent by early April 2020 compared with mean 2019 levels. Just under 50 percent of the changes were attributable to vehicle travel.
At their peak, emissions in individual countries declined by 26 percent, on average. The effect on 2020 annual greenhouse gas (GHG) emissions depends on the duration of the shutdowns, with a low estimate of a 4 percent decline if pre-pandemic conditions returned by mid-June 2020 (clearly not the case), and a high estimate of 7 percent if some restrictions remain worldwide until the end of the year. Note that the above estimates were made based on what the authors termed a confinement index. The confinement index used a scale of 0 to 3 and allocated the degree to which normal daily activity was constrained for all or part of the population for each geographic area (i.e., country).
Because the CO2 emission estimates in the Nature Climate Change analysis were based on surrogate data (the confinement index), it is useful to examine U.S. Department of Energy estimates of energy consumption and resulting carbon emission estimates for the first three months of 2020. These data show that CO2 emissions in the United States from energy consumption in March 2020 were down 14 percent from year-earlier values.