Climate change linked to forest fires

Global warming is causing forest fires in northern latitudes to burn more frequently and fiercely, contributing to the threat of runaway climate change, according to a new environmental study. The report published in Nature Geoscience, found that the increased intensity of fires in Alaska's vast interior over the last decade has changed the region from a sink to a source of carbon dioxide, the greenhouse gas most responsible for heating up the planet, the study found. In other words, boreal forests in the northern hemisphere may now soak up less of the heat-trapping gas than they give off. The bulk of the released CO2 comes not from the burning trees, but from what is in the ground. "Most of what fuels a boreal fire is plant litter, moss and organic matter in surface soils," Merritt Turetsky, a professor at the University of Guelph in Ontario and lead author of the study, said. Turetsky said that the findings were worrying because about half of the world's soil carbon was trapped in northern permafrost and peatlands. "This is carbon that has accumulated in ecosystems a little bit at a time for thousands of years, but is being released very rapidly."