1 of 3 | Heat-trapping atmospheric carbon dioxide, caused by burning fossil fuels, hit record levels in May and peaked at 424 parts per million, according to scientists at NOAA and Scripps Institution of Oceanography. File Photo by Ryan Tong/EPA-EFE
June 5 (UPI) -- Heat-trapping carbon dioxide soared to record levels in May, peaking at 424 parts per million and blowing past levels not seen in more than 4 million years, scientists announced Monday.
The annual increase in the Keeling Curve, measured at the National Oceanic and Atmospheric Administration's Mauna Loa Atmospheric Baseline Observatory, is one of the largest on record, according to scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego.
"Every year we see carbon dioxide levels in our atmosphere increase as a direct result of human activity," said NOAA administrator Rick Spinrad.
"Every year, we see the impacts of climate change in the heat waves, droughts, flooding, wildfires and storms happening all around us," Spinrad added. "While we will have to adapt to the climate impacts we cannot avoid, we must expend every effort to slash carbon pollution and safeguard this planet and the life that calls it home."
The rise in carbon dioxide levels has been extreme since the advent of industrialization.
"CO2 levels are now more than 50% higher than they were before the onset of the industrial era," Scripps Institution of Oceanography announced in a tweet Monday.
Carbon dioxide generally peaks annually in the Northern Hemisphere in May. This year's 424.0 parts per million is a 3.0 ppm increase over May of 2022 and is the fourth-largest annual increase on the Keeling Curve.
This year's measurements were taken from a temporary sampling site at the summit of Hawaii's Mauna Kea volcano after lava flows cut off access to the Mauna Loa observatory in November 2022. Scripp's May measurements came in at 423.78 ppm and were taken at Mauna Loa.
Every year, NOAA's Global Monitoring Laboratory takes the Mauna Loa data and combines the measurements with sampling stations from around the world.
The United Nations' World Meteorological Organization also warned in November that emissions levels for all three main greenhouse gases -- carbon dioxide, methane and nitrous oxide reached record highs in 2021.
Scientists blame the burning of fossil fuels to generate electricity and provide transportation for carbon dioxide pollution, with additional blame on deforestation and agriculture. Carbon dioxide traps heat, like other greenhouse gases, and increases the onset of extreme weather events, such as heat waves and flooding.
In addition to rising seas, scientists warn increasing carbon dioxide threatens the world's oceans by raising water temperatures and disrupting marine ecosystems.
"What we'd like to see is the curve plateauing and even falling because carbon dioxide as high as 420 or 425 parts per million is not good," Scripps geochemist Ralph Keeling warned.
"It shows that as much as we've done to mitigate and reduce emissions, we still have a long way to go."