Methane recently reached 1,900 parts per billion (ppb) of Earth’s atmosphere according to measurements taken by the National Oceanic and Atmospheric Administration (NOAA) in the US. This compares with about 700 ppb before the industrial revolution.
Methane is a powerful greenhouse gas, but lasts around nine years in the air. Including the knock-on effects it has on other gases, its total global warming impact since 1750 is roughly half that of CO₂.
