Climate Change And Permafrost Thaw Alter Greenhouse Gas Emissions

Permafrost – the perpetually frozen foundation of North America – isn’t so permanent anymore, and scientists are scrambling to understand the pros and cons when terra firma goes soft. Permafrost serves like a platform underneath vast expanses of northern forests and wetlands that are rooted, literally, in melting permafrost in many northern ecosystems. But rising atmospheric temperatures are accelerating rates of permafrost thaw in northern regions, says MSU researcher Merritt Turetsky.

In the report, “The Disappearance of Relict Permafrost in Boreal North America: Effects on Peatland Carbon Storage and Fluxes,” in this week’s online edition of Global Change Biology, Turetsky and others explore whether melting permafrost can lead to a viscous feedback of carbon exchange that actually fuels future climate change.
“The loss of permafrost usually means the loss of terra firma in an otherwise often boggy landscape,” Turetsky said. “Roads, buildings and whole communities will have to cope with this aspect of climate change. What this means for ecosystems and humans residing in the North remains of the most pressing issues in the climate change arena.”

Working closely with researchers from Southern Illinois University, Villanova University and the National Renewable Energy Laboratory, Turetsky, assistant professor of crop and soil sciences and fisheries and wildlife, found that permafrost degradation has complex impacts on greenhouse gas fluxes from northern wetlands.

Their study focused on peatlands, a common type of wetland in boreal regions that slowly accumulates peat, which is an accumulation of partially decayed vegetation. Today, peatlands represent a massive reservoir of stockpiled carbon that accumulated from the atmosphere over many thousands of years. Peat blankets the permafrost and protects it like a thick layer of insulation.

“We find permafrost in peatlands further south than in other boreal ecosystems due to the insulating qualities of peat.So we have argued that these ecosystems serve as a very sensitive indicator of climate change,” Turetsky said. “What will happen to peatlands when climate change disrupts these frozen layers, or perhaps more importantly what will happen to all of that stored carbon in peat, have remained big questions for us.”

TerraDaily