Atmospheric methane levels surged by a record-breaking amount in 2021, NOAA says

The atmospheric concentration of methane — a greenhouse gas that contributes significantly to global warming — increased by a record amount in 2021 for the second year in a row, the National Oceanic and Atmospheric Administration said Thursday. Levels of carbon dioxide also increased at a "historically high rate," NOAA said. 

A preliminary analysis showed atmospheric methane levels increased by 17 parts per billion (ppb) in 2021, which NOAA said was "the largest annual increase recorded since systematic measurements began in 1983." Atmospheric methane levels averaged 1,895.7 ppb in 2021, which is approximately 162% higher than pre-industrial levels.

NOAA's findings also provided alarming news about carbon dioxide, which it said was the primary contributor to human-caused global warming. Last year was the 10th year in a row that saw a more than 2 parts per million increase, which NOAA said is the "fastest sustained rate of increase in the 63 years since monitoring began." Approximately 36 billion tons of carbon dioxide were emitted due to human activity in 2021, NOAA said.