If you’ve noticed that your grass grew a little fuller and faster this year, it could be due to the pandemic lockdowns.
People drove a lot less. They went to work less. This shut down polluting factories around the world, and decreased smog. More sunlight got through to the plants, and that made the plants grow more. Maybe it required mowing the lawn a couple more times over the summer if you’re the kind of person who likes a trim yard.
But China, on an absolute basis, pollutes about as much as the next top three: the United States, India, and Russia. The worst polluters on a per capita basis are Saudi Arabia, Kazakhstan, and Australia. So gardeners in all of these countries might have noticed bigger tomatoes and zucchinis last spring and summer. But among the biggest of effects would most likely be found in China.
Apparently, as air pollution has increased over the years in China, spring has come later and later. When pollution dropped in early 2020, spring snapped back to closer to its normal non-pollution state, which was about 8 days earlier.
On Aug. 25, the Washington Post reported on the data, from a study published in the journal Science Advances. The study proffers hope that nature can snap back to its prior ebullience once humans scale up cleaner sources of energy, or decrease their emissions in other ways, for example by traveling less by airline and car, and decreasing our utilization of electricity and heat.
“The vegetation basically responded immediately to the change in conditions,” professor John P. Wilson, who co-authored the study, told the Post. The co-authors wrote that “short-term changes in human activity can have a relatively rapid ecological impact.” Their study showed a nitrogen dioxide reduction in China during lockdown, caused by less burning of fossil fuels.
The skies cleared in China. More sunlight got through to the plants, which caused an earlier spring by 8.4 days, and increased leaf area coverage by 17.45 percent, according to satellite data reported in the study.
Could it mean that climate change is not as irreversible as most scientists think? I don’t know, and Wilson did not immediately respond to a request for comment. But, plant growth is not the same as global warming. Presumably, plant growth could snap back after a decrease in smog, but a buildup of GHGs over decades could continue to sustain a warmer climate.
Princeton professor David Wilcove, a conservation biologist, spoke to the Post about the data showing increased plant growth in China. “It’s very intriguing. It potentially shows the complex set of cascading events that can follow from human activity or the cessation of human activity.”
Shutdowns in other countries have also likely decreased smog, increased radiation from the sun, and consequently increased photosynthetic activity. Nitrogen dioxide levels over Italy have plummeted, according to the Post’s own satellite data analysis. On a global level, another study showed carbon dioxide emissions dropping approximately 2.5 billion tons in 2020. That is equivalent to removing approximately 500 million cars from the road. An additional study found a peak drop of 17 percent of global emissions in April 2020.
And, emissions are again rising in 2021. According to the U.S. International Energy Agency (IEA), emissions have strongly rebounded throughout the world. China is the leading global emitter, being the only major economy to increase GHGs (greenhouse gas emissions) by 1.7 percent, in 2020. China’s economy, and emissions, made up for lost time toward the end of the year, after decreases in emissions due to lockdowns in early 2020.
This is an additional concern about pandemic lockdowns in the West—they could decrease the economic power of democracies at a critical time in the competition with China. If pandemics cause severe lockdowns in democracies, but only minor problems in China, then China’s economy could benefit from the next pandemic, relative to democracies. China could then purposefully cause such a pandemic, or be negligent in its biosafety controls, knowing that if a pandemic results, its relative economic strength would actually increase.
Wilson’s study gave him hope that environmental degradation can be turned around. “I take comfort from a natural experiment like this that we can change the world,” he told the Post. “What we’re trying to do is motivate people to take those first few steps.”
I want to believe that he is right. If so, that increases the responsibility of this generation to be a little less selfish, and to do a little more for the environment. That should start with China’s standing down its military aggression, which leads to military and economic competition, and thus more emissions, rather than a gradual decrease in polluting activities.
