Permafrost may have far-reaching effects on climate change, a new study suggests.

The findings, published in the Proceedings of the National Academy of Sciences, offer new evidence that permafrost thawing releases large amounts of greenhouse gases, which can raise global temperatures.

"We've known for a while now that permafrost is thawing," Suzanne Hodgkins, the lead author on the paper, said in a statement. "But what we've found is that the associated changes in plant community composition in the polar regions could lead to way more carbon being released into the atmosphere as methane."

Permafrost, which is a thick layer of soil that remains frozen year-round, is usually found in the world’s polar regions. The latest study shows that as permafrost melts, it produces releases significant amounts of methane. Compared to carbon dioxide, methane is 33 times more effective as a greenhouse gas.

The study involved taking samples from soil in Sweden. Researchers found that if permafrost melts entirely, there will likely be five times as much carbon in the atmosphere than there is today.

"The world is getting warmer, and the additional release of gas would only add to our problems," said Jeff Chanton, a researcher from Florida State University.

Permafrost covers about 24 percent of all land in the northern hemisphere and stores approximately 1.5 trillion tons of carbon -- twice the amount currently found in the atmosphere. A 2012 study predicted that greenhouse gases released from melting permafrost could increase the world’s temperature by an additional 1.5 degrees Fahrenheit within the next century.

Ted Schuur, a permafrost expert at the University of Florida, conducted his own field research on permafrost and climate change in Alaska. He said that climate change and permafrost thawing are linked at the point where the melting triggers further warming.

"We're on the edge of a major transition point," Schuur told USA Today about one of his studies, which found that tundras worldwide may be releasing more carbon dioxide into the atmosphere than they can absorb. The resulting emissions may resemble those caused by deforestation, but they are not as harmful to the environment as emissions from power plants and cars.

The latest study is part of a larger multicontinent effort that included researchers from North America, Europe and Australia.