Atmospheric carbon dioxide levels have exceeded a major milestone

The amount of heat-trapping carbon dioxide in the atmosphere has exceeded a major milestone—more than 50% higher than in pre-industrial times—and was not observed millions of years ago when Earth was an ocean-flooded greenhouse. planetFederal scientists announced Friday.

The National Oceanic and Atmospheric Administration said its tallest observation station in Mauna Loa, Hawaii, averaged 421 parts per million carbon dioxide for the month of May, the time when the greenhouse gas reaches its highest levels of the year. Scientists said that before the Industrial Revolution in the late 19th century carbon dioxide levels were 280 parts per million, so humans changed the atmosphere dramatically. Some activists and scientists want the 350 ppm level. Industrial carbon dioxide emissions come from burning coal, oil and gas.

Scientists say gas levels keep rising, when they need to be low. This year’s CO2 level is up about 1.9 parts per million from last year, a slightly bigger jump from May 2020 to May 2021.

Peter, a climate scientist at NOAA Tans, who tracks the agency’s global greenhouse gas emissions, said.

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Scientists from abroad said the numbers show a severe climate change problem.

University of WisconsinMadison climatologist Andrea Dutton. “If we stay on the track with a plan to jump out of the way at the last minute, we may die of heat stroke on the rails before they even get to us.”

More heat waves, more floods

Without cuts in carbon pollution, said University of Illinois climate scientist Donald Whipples, “we will see more devastating levels of climate change, more heat waves, more floods, more droughts, more big storms, and higher sea levels.”

The slowdown caused by the pandemic cut global carbon emissions slightly in 2020, but they rebounded last year. Both changes were small compared to the amount of carbon dioxide pumped into the atmosphere each year, Tans said, especially if we consider that carbon dioxide stays in the atmosphere from hundreds to a thousand years.

The world puts about 10 billion metric tons of carbon into the air each year, much of it being pulled up by oceans and plants. This is why May is the peak month for global carbon dioxide emissions. Plants in the northern hemisphere begin to absorb more carbon dioxide in the summer as they grow.

Carbon dioxide accumulation has reached the highest level in human history

A refinery owned by Citgo, a subsidiary of the state-owned Venezuelan Oil Corporation, is located along the I&M Canal on May 15, 2019 in Lemonte, Illinois. (Photo by Scott Olson/Getty Images)

The National Oceanic and Atmospheric Administration (NOAA) said carbon dioxide levels are now about the same as 4.1 to 4.5 million years ago in the Pliocene, when temperatures were 7 degrees (3.9 degrees Celsius) higher and sea levels were 16 to 82 degrees higher. feet (5 to 25 metres) from now. . South Florida, for example, was completely submerged. These are conditions that human civilization has not known.

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The reason the atmosphere warmed and sea levels rose millions of years ago at the same carbon dioxide level as it is now is that the natural increase in carbon dioxide levels in the past was more gradual. With carbon staying in the air for hundreds of years, temperatures rose over longer periods of time and stayed there. Tans and other scientists said that the Antarctic and Greenland ice sheets have melted over time, dramatically raising sea levels, making Earth darker and reflecting a lower temperature than the planet.

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Scientists at the Scripps Institution of Oceanography calculated levels slightly differently based on time and mean, and put the May average at 420.8 parts per million, just below the NOAA number.