Taller Arctic Plants Could Speed Dangerous Warming Feedback Loop

Climate change is giving Arctic plants a growth spurt.

A study published in Nature Wednesday examined seven key plant characteristics over 30 years of warming at 117 locations in the Arctic or alpine tundra and found that plants were growing taller at all locations studied.

The international team of scientists, led by Aarhus University in Denmark as well as researchers at the University of Edinburgh and the Senckenberg Biodiversity and Climate Research Center in Frankfurt, also found that taller plant species like vernal sweetgrass, common in the European lowlands, are moving north to locations in Iceland and Sweden, according to a University of Edinburgh press release.

"Quantifying the link between environment and plant traits is critical to understanding the consequences of climate change, but such research has rarely extended into the Northern hemisphere, home to the planet's coldest tundra ecosystems. This is the first time that a biome-scale study has been carried out to get to the root of the critical role that plants play in this rapidly warming part of the planet," University of Edinburgh School of GeoSciences researcher Isla Myers-Smith said in the press release.

Florida International University (FIU) ecologist Steven Oberbauer, who participated in the research, said the increased plant height had serious implications for the state of Arctic soil.

Arctic plants are historically small because the frozen soil does not release many nutrients, but as it thaws, it releases more plant food, as well as something much more dangerous.

"Cold and wet tundra soil holds large amounts of organic carbon as peat. But, as temperatures rise and the soil thaws, the organic matter decomposes, releasing the greenhouse gases carbon dioxide and methane to the atmosphere, causing further warming," Oberbauer said in a FIU press release emailed to EcoWatch. "We're better off if things stay frozen."

Plant height could actually speed up as well as signal the warming process. Taller plants trap snow, which insulates the soil and prevents it from freezing as quickly, the University of Edinburgh press release said.

And the plants are only expected to grow taller as temperatures warm.

"If taller plants continue to increase at the current rate, the plant community height could increase by 20 to 60 percent by the end of the century," Anne Bjorkman of the Climate Research Center said in the University of Edinburgh press release.

The research comes as concern grows about the release of methane from melting Arctic permafrost, which contains 30 to 50 percent of the world's soil carbon, according to the University of Edinburgh.

A study published in August found that greenhouse gas emissions from lakes formed from melting permafrost could more than double the estimate of how much carbon the Arctic thaw would release into the atmosphere.