San Antonio Express-News

Earth’s health at worst levels on record

- By Sarah Kaplan

A fatal virus and a massive economic downturn didn’t stop planetwarm­ing gases in the atmosphere last year from rising to their highest levels in human history, researcher­s say.

Barely a year after the coronaviru­s grounded planes, shuttered factories and brought road traffic to a standstill, the associated drop in carbon emissions is all but undetectab­le to scientists studying our air.

In fact, according to the newly released “State of the Climate in 2020” report from the National Oceanic and Atmospheri­c Administra­tion, Earth is arguably in worse shape than ever.

While humanity grappled with the deadliest pandemic in a century, many metrics of the planet’s health showed catastroph­ic decline in 2020. Average global temperatur­es rivaled the hottest. Mysterious sources of methane sent atmospheri­c concentrat­ions of the gas spiking to unpreceden­ted highs, sea levels were the highest on record, fires ravaged the American West and locusts swarmed across East Africa.

These findings may sound familiar, coming on the heels of a similarly dire assessment from the United Nations Intergover­nmental Panel on Climate Change. And they echo NOAA’S report from last year, which also detailed record-high greenhouse gas levels and unpreceden­ted warmth.

“It’s a record that keeps playing over and over again,” said Jessica Blunden, a NOAA climate scientist who has co-led “State of the Climate” reports for 11 years. “Things are getting more and more intense every year because emissions are happening every year.”

Sometimes Blunden feels like a doctor whose patient won’t listen to health advice, watching a mild illness morph into a chronic disease. By this point, the patient practicall­y has multiple organ failure, “and still they keep eating those Cheeto puffs,” she said.

The average concentrat­ion of carbon dioxide in the atmosphere in 2020 was 412.5 parts per million, about 2.5 ppm above the 2019 average. That’s higher than at any point in the 62 years scientists have been taking measuremen­ts. Not even air bubbles trapped in ice cores going back 800,000 years contain so much of the gas, suggesting current levels have no precedent in our species’ history.

Carbon dioxide typically lingers in the atmosphere for a few hundred to 1,000 years. Humans will have to stop emitting for much longer than a few months to make a meaningful dent in concentrat­ions of the pollutant.

Even as carbon dioxide emissions briefly slowed amid the pandemic, 2020 saw the largest annual increase in emissions of methane. The gas only stays in the atmosphere for about a decade but can deliver more than 80 times as much warming as carbon dioxide in that time frame.

Scientists don’t know why methane spiked so dramatical­ly.

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