The amount of methane gas escaping from the ground during the long cold period in the Arctic each year (generally from September through May) and entering Earth’s atmosphere is likely much higher than estimated by current carbon cycle models. A team led by San Diego State University and including scientists from NASA’s Jet Propulsion Laboratory found that far more methane escapes from the Arctic tundra during the cold months when the soil surface is frozen than prevailing assumptions and carbon cycle models previously assumed. At least half of the annual methane emissions occur in the cold months. Drier tundra can be a larger emitter of methane than wet tundra.
Methane is a potent greenhouse gas that contributes to atmospheric warming. It is approximately 25 times more potent per molecule than carbon dioxide over a 100-year period. Over the past several decades, scientists used specialised instruments to accurately measure methane emissions in the Arctic and incorporated those results into global climate models. However, almost all of these measurements were obtained during the Arctic’s short summer. The region’s long, brutal cold period, which accounts for between 70 and 80 % of the year, has been largely overlooked. Most researchers figured that because the ground is frozen during the cold months, methane emissions practically shut down. That this assumption turns out to be incorrect is very bad news. The methane problem has every potential to lead mankind into extremely dangerous waters. The only way to decrease these methane emissions is to radically decrease CO2 emissions.