The terrible situation caused by the coronavirus shutdowns across the world has led to an interesting experiment in air quality. What happens to the environment here and abroad when worldwide transportation and industrial production drop off significantly? Reading the news, the improvements seem to be significant. News reports with headlines such as “Coronavirus Got Rid of Smog” abound, and CNN posted some eye-popping before and after photos of cities such as New Delhi.
But photos can be deceiving. That CNN article compared a photo of New Delhi in March 2020 to one from November 2019, but for the one U.S. city it profiled, Los Angeles, it had to go all the way back to 1998 to find an appropriately smoggy photo. A closer look at the data shows how transportation and industrial production reductions don’t move the needle nearly as much in the already-safe American environment as they do in other countries with much more polluted air.
The study referenced by that article shows that particulate matter levels in Los Angeles and New York were a mere 6-8 micrograms per cubic meter in 2019, one-tenth of New Delhi’s levels and close to natural levels from dust. The declines from 2019 to 2020 in New York and Los Angeles due to the shutdowns are barely noticeable within the context of normal year-to-year variation, unlike the visibly apparent differences in heavily polluted places such as New Delhi.
There is also the issue of timing. Several articles trumpeted how in March, Los Angeles saw its longest stretch of meeting air quality standards since at least 1980 (when data started being collected regularly). However, many of those articles ignore that the stretch began on March 7, before the statewide stay-at-home order went into effect on March 19, and ended around the end of the month, with the lockdown still in full effect.
As a spokesman for the South Coast Air Quality Management District noted, “Weather has by far the greatest impact on air quality, and in recent weeks, Los Angeles has seen an increase in rainfall and stormy weather.”
Regardless of weather, Los Angeles has seen levels for all pollutants drop by at least half over the past 50 years. Recent changes up or down are mere blips in comparison to the overall trend. The entire United States has been on a decadeslong trend of improving air quality, with aggregate emissions down 74% since 1970.
But the actual data reveal a steep decline for New York in early February, followed by no noticeable decline after the shutdowns took hold in March. The data for Boston and Washington, D.C., are decidedly mixed, with the difference between this year and the five-year average being noticeable in March but much smaller in April.
As NASA cautions in the article, “Further analysis will be required to rigorously quantify the amount of the change in nitrogen dioxide levels associated with changes in emissions versus natural variations in weather.”
It is also likely that the early shutdowns in China, which were documented to improve Asian air quality at the beginning of the year dramatically, helped improve air quality in Southern California before shutdowns took hold in the U.S. Studies have found that a large amount of air pollution in the Western U.S. is transported from East Asia, so this window of time may end up being a compelling case study about that phenomena.
In the meantime, be wary about headlines implying that our environment is unsafe when our economy is not shut down, and remember that the U.S. is an unqualified success story in improving air quality while expanding our economy and energy use. With ambient air pollution approaching natural levels, the vast majority of U.S. air is among the safest in the world.
This “greatest story never told” is brought to light by a newly released short animated video that makes this otherwise complex story more accessible to everyday people. The video also explains how over-regulating domestic energy in a way that shifts jobs and industry overseas to lesser-regulated nations does more harm than good to populations here and abroad.
While the experts all agree that we need to gather more data, it appears the COVID-19 shutdowns are showing us just how clean our air already is and how much more progress our global competitors can make if they emulate the way the U.S. has made our air safe — with fossil fuels, not despite them; by using science and technology, not ideology.