Amount of carbon dioxide in air hits new peak, growing at near-record fast rate
The cause of global warming is showing no signs of slowing as heat-trapping carbon dioxide in Earth’s atmosphere increased to record highs in its annual spring peak, jumping at one of the fastest rates on record, officials announced Monday.
Carbon dioxide levels in the air are now the highest they’ve been in more than 4 million years because of the burning of oil, coal and gas.
The last time the air had similar amounts was during a less hospitable hothouse Earth before human civilization took root, scientists said.
The National Oceanic Atmospheric Administration announced that the carbon dioxide level measured in May in Hawaii averaged 424 parts per million. That’s 3 parts per million more than last year’s May average and 51% higher than pre-industrial levels of 280 ppm. It is one of the largest annual May-to-May increases in carbon dioxide levels on record, behind only 2016 and 2019, which had jumps of 3.7 and 3.4 parts per million.
“To me as an atmospheric scientist, that trend is very concerning,” said NOAA greenhouse gas monitoring group leader Arlyn Andrews. “Not only is CO2 continuing to increase despite efforts to start reducing emissions, but it’s increasing faster than it was 10 or 20 years ago.”
Emissions used to increase by maybe 1 part per million per year, but now they are increasing at twice and even three times that rate, depending on whether there is an El Nino, Andrews said.
“The relentless rise in atmospheric CO2 is incredibly worrying if not wholly predictable,” said Brown University climate scientist Kim Cobb, who was not part of the research.
Carbon dioxide levels are rising so that each year is higher than the last.
However, there’s a seasonal cycle with carbon dioxide so that it reaches its highest saturation point in May. That’s because two-thirds of the globe’s land is in the northern hemisphere and plants suck carbon dioxide out of the air, so during late spring and summer carbon dioxide levels fall until they start rising again in November, Andrews said.
Carbon dioxide levels rise more during El Niño climate cycles because it is hotter and drier in the Tropics. An El Niño is brewing. That 3.0 increase may be a sign of an El Niño
bump, she said.
There are two main ways of tracking greenhouse gases. One is to monitor what’s coming out of smokestacks and exhaust pipes, but about half of that is absorbed by the oceans and lands, Andrews said.
The other way is to measure how much carbon dioxide is in the air. NOAA and partner agencies measure all around the world. Hawaii has the longest history of direct measurements
and is the home of the Scripps Institution of Oceanography’s Keeling Curve, which has kept track of carbon in the air since 1958 when the May reading peaked at 317.5. Emissions have gone up about 33% since then.
“Current emissions are going to remain in the atmosphere for thousands of years and they’re going to continue to trap heat energy near Earth’s surface for thousands of years,” Andrews said.