NOAA: Powerful heat-trapping methane rises at record speed

Global atmospheric levels of the potent but short-lived greenhouse gas methane rose by a record amount last year, the National Oceanic and Atmospheric Administration said Thursday, worrying scientists because of methane’s larger role in climate change.

Initial air levels of methane jumped by 17 parts per billion, up from 1895.7 parts per billion last year. According to NOAA, this is the second year in a row that methane has grown at a record rate, up 15.3 ppb compared to 2019. Atmospheric scientist Lindsay Lan of NOAA and the University of Colorado said methane levels are now more than double the pre-industrial level of 720 parts per billion.

According to the Intergovernmental Panel on Climate Change, methane is a major contributor to climate change, causing temperatures to increase by about 0.9 degrees Fahrenheit (0.5 degrees Celsius) since the 19th century. Carbon dioxide has caused about 50% more warming than methane.

“This trend of rapid increase in methane is extremely disturbing,” said methane researcher Robert Howarth of Cornell University.

Methane is about 25 times more powerful at trapping heat than carbon dioxide. But it stays in the air for only nine years instead of thousands of years like carbon dioxide, Lan said. Because it doesn’t stay in the air for long, last year many countries called for accelerated emissions cuts as a low-hanging fruit in global efforts to limit future warming to 1.5 or 2 °C (2.7 or 3.6 °F). agreed to target methane. Industrial time. The world has already warmed by 1.1 to 1.2 °C (about 2 to 2.2 °F).

“To limit warming to below 2C this century, we need to cut our methane emissions dramatically, and today we are clearly Heading in the wrong direction.” “Cutting methane has immediate climate benefits, as it is the only greenhouse gas for which reduction in emissions can cool the climate quickly (versus slowing or stopping the rate of warming).

NOAA has been tracking methane levels in the air since 1983.

Lan said early signs point more to the natural causes of the methane jump, because of La Nia, the natural and temporary cooling of parts of the Pacific that change seasons around the world, but it’s still early. La Nia makes rainfall more frequent in some tropical regions and two years in a row of records increased during La Nia, pointing to methane escaping from wetlands, she said.

Methane is also a natural gas and an increasingly used source of energy. Most of the methane is released from livestock and human-caused agriculture, as well as from landfills. Scientists also fear future release of trapped methane under the ocean and in frozen Arctic land, but there is no sign that this is happening on a large scale.

Stanford University climate scientist Rob Jackson said the important question is whether this increasing trend could be adding to the problems of climate change or a pandemic-related blip due to a reduction in nitrous oxide destroying methane from fewer car and industrial pollution. Is.

“It seems to be something other than COVID,” Lan said. That high level in 2020 and then even higher in 2021, when the lockdown was eased, is far from a pandemic impact.

Howarth said both fossil fuels and agriculture are leading the way in methane growth. But he added, “My research points to fossil fuel growth being the biggest driver since 2008, with shale gas production from fracking in the US being a major part of the increase.”

In a study last year, Lan looked to isolate chemical isotopes where methane emissions have been increasing steadily since 2006. The chemical signature pointed to natural wetland emissions or agriculture as the bigger culprit than fossil fuels, she said.

NOAA also said last year that atmospheric carbon dioxide levels increased by 2.66 parts per million in 2020, one of the highest increases in history, but not a record. The 2021 annual average for carbon dioxide was 414.7 parts per million. Pre-industrial is about 280 parts per million. NOAA said carbon dioxide is now at its highest after about 4.3 million years when sea levels were about 75 feet (23 meters) higher and average temperatures were about 7 degrees Fahrenheit (3.9 degrees Celsius) warmer.

“Our data shows that global emissions are rapidly moving in the wrong direction,” NOAA chief Rick Spinrad said in a statement.

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