Global emissions of methane, the second-biggest contributor to human-caused climate change after carbon dioxide, surged by a record amount in 2021, U.S. National Oceanic and Atmospheric Administration said on Thursday.
Methane, a key component of natural gas, is 84 times more potent than carbon dioxide but doesn’t last as long in the atmosphere before it breaks down. Major contributors to methane emissions include oil and gas extraction, landfills and wastewater, and farming of livestock.
“Our data show that global emissions continue to move in the wrong direction at a rapid pace,” Rick Spinrad, the NOAA administrator, said in a statement. “The evidence is consistent, alarming and undeniable.”
NOAA said the annual increase in atmospheric methane last year was 17 parts per billion, the largest amount recorded since systematic measurements began in 1983. The increase in methane during 2020 was 15.3 parts per billion. In 2021, atmospheric methane levels averaged 1,895.7 parts per billion, or roughly 162% greater than preindustrial levels, NOAA said.
The report comes after more than 100 countries joined a coalition to cut 30% of methane gas emissions by 2030 from 2020 levels. The Global Methane Pledge of 2021 includes six of the world’s 10 biggest methane emitters — the U.S., Brazil, Indonesia, Nigeria, Pakistan and Mexico. China, Russia, India and Iran did not join the pledge.
Last year, a landmark United Nations report declared that drastically slashing methane is necessary to avoid the worst outcomes of global warming. The report said if the world could cut methane emissions by up to 45% through 2030, it would prevent 255,000 premature deaths and 775,000 asthma-related hospital visits on an annual basis.
Kassie Siegel, director of the Center for Biological Diversity’s Climate Law Institute, said reducing methane is a relatively cheap and easy way to achieve significant climate benefits.
“Methane reductions have to be one part of a transformative global effort to phase out deadly fossil fuels in favor of truly clean renewable energy,” Siegel said in a statement. “Anything less puts us on a catastrophic path to an unrecognizable world.”
A study published in the journal Environmental Research Letters also found that slashing methane emissions from the oil and gas industry, agriculture and other human sources could slow climate change by as much as 30%.
NOAA also warned that carbon dioxide is continuing to rise at historically high rates.
The global surface average for carbon dioxide last year was 414.7 parts per million, an increase of 2.66 parts per million over the 2020 average, the agency said. The measurement marks the 10th consecutive year that carbon dioxide rose by more than two parts per million, the fastest rate of increase since monitoring began 63 years ago.
While there’s been some debate on the cause of the ongoing rise in methane emissions, carbon dioxide emissions are the main driver of human-caused climate change, NOAA said.
“The effect of carbon dioxide emissions is cumulative,” Pieter Tans, a senior scientist with the Global Monitoring Laboratory, said in a statement.
“About 40% of the Ford Model T emissions from 1911 are still in the air today,” Tans said. “We’re halfway to doubling the abundance of carbon dioxide that was in the atmosphere at the start of the Industrial Revolution.”