Heat-trapping carbon dioxide sets record high, scientists say

KENSINGTON, Maryland — The world hit another new record high for heat-trapping carbon dioxide in the atmosphere, despite reduced emissions because of the coronavirus pandemic, scientists announced on Thursday.

Measurements of carbon dioxide, the chief greenhouse gas, averaged 417.1 parts per million at Mauna Loa, Hawaii, for the month of May, when carbon levels in the air peak, the National Oceanic and Atmospheric Administration said. That’s 2.4 parts per million higher than a year ago.

Even though emissions of carbon dioxide from the burning of fossil fuels dropped by as much 17 per cent in April, it was a brief decline. Carbon dioxide can stay in the air for centuries, so the short-term reductions of new carbon pollution for a few months didn’t have much of a big-picture effect, said NOAA senior scientist Pieter Tans.

“It illustrates how difficult it is — what a huge job it is — to bring emissions down,” Tans said.

“We are really committing the Earth to an enormous amount of warming for a very large time.”

Records with direct measurements go back to 1958. And carbon dioxide levels are now nearly 100 parts per million higher than then. That’s a 31 per cent increase in 62 years.

“The rise in atmospheric carbon dioxide levels is relentless, and this means the costs of climate change to humans and the planet continue to rise relentlessly as well,” said University of Michigan environment dean Jonathan Overpeck.