An exceptional wildfire in northern Alaska in 2007 put as much carbon into the air as the entire Arctic tundra absorbs in a year, scientists say.

The Anaktuvuk River fire burned across more than 1,000 sq km (400 sq miles), doubling the extent of Alaskan tundra visited by fire since 1950.

With the Arctic warming fast, the team suggests in the journal Naturethat fires could become more common.

If that happens, it could create a new climate feedback, they say.

Fires in the tundra are uncommon because the ground is covered in snow and ice for large periods of the year.

Read More...........
Reproduced under licence from BBC News © 2011 BBC