One the one hand, cutting fossil fuel pollution is necessary for avoiding severe destruction over the long term. But such cuts will make the earth much hotter in the short term.
One recent study cast the well-known declines in air pollution during the COVID-19 pandemic in a darker light.
These cuts remain one of the only examples of successful cuts to climate-warming pollution, but the new study found that those pandemic-era cuts in air pollution led to a rise in global temperatures.
The findings, published on Wednesday in the journal NPJ Climate and Atmospheric Science, unveil a stark paradox at the heart of human-caused climate change.
It suggests that while cutting fossil fuel pollution is necessary for avoiding severe destruction over the long term — such cuts will make things noticeably worse in the short term.
The pandemic-era economic slowdown led to “a large-scale geophysical experiment,” study leader Örjan Gustafsson of Stockholm University said in a
statement.
That’s because the shuttered factories and power plants led to a corresponding crash in emissions.
Even so, not all emissions fell in the same way.
From a research station in the Maldives, an island archipelago off the coast of India, Gustafsson’s team detected that when pollution from smokestacks fell, so did concentrations of aerosols — tiny floating particles that hang in the atmosphere.
That fall was an unmistakable boon to public health. According to Our World in Data, these contaminants — like tiny floating particles of soot or sulfates — cause millions of global deaths per year.
But for all the damage they do to human lungs, aerosols also help shade the earth by scattering light particles from the sun that would otherwise warm the planet.
After the cuts, the study found that light reaching the surface increased by 7 percent.
“While the sky became bluer and the air cleaner, climate warming increased when these cooling air particles were removed,” Gustafsson said.
While aerosol concentrations fell as the smokestacks shut off, other gases remained stubbornly high.
In particular, levels of the most potent climate-warming gases — like carbon dioxide — barely changed.