Arctic permafrost is thawing as the Earth warms due to climate change.
Arctic permafrost is thawing as the Earth warms due to climate change. In some cases, scientists predict that this thawing soil will release increasing amounts of methane, a potent greenhouse gas, that is known to trap more heat in our planet’s atmosphere.
Now a University of Washington-led team has found a new reason behind increased methane emissions from a thawing permafrost bog in Alaska: Early spring rainfall warms up the bog and promotes the growth of plants and methane-producing microbes. The team showed that early precipitation in 2016 warmed the bog about three weeks earlier than usual, and increased the bog’s methane emissions by 30 percent compared to previous years. These results were recently published in Geophysical Research Letters.
“In general, the chance of generating methane goes up with increased rainfall because soils get waterlogged. But what we see here is different,” said corresponding author Rebecca Neumann, an associate professor in the UW Department of Civil & Environmental Engineering. “Early rainfall sent a slog of warm water moving into our bog. We believe microbes in the bog got excited because they were warmed up, so they released nutrients from the soil that allowed more plant growth. Methane production and emission are tightly linked with soil temperature and plant growth.
Read more at University of Washington
Image: A UW-led team has found that early spring rainfall warms up a thawing permafrost bog in Alaska and promotes the growth of plants and methane-producing microbes. CREDIT: Rebecca Neumann / University of Washington