Tree line movement may have been exaggerated by a factor of 20

Beware: Trees are on the move! « Tallbloke's Talkshop

“To generalize our results, the tree line is definitely moving north on average but we do not see any evidence for rates as big as 2 KILOMETERS per year anywhere along the Arctic rim,” he said in a release. “Where we have the most detailed information, our results suggest that a rate of around 100 METERS per year is more realistic. In some places, the tree line is actually moving south. The predictions of a loss of 40 percent of the tundra by the end of the century is probably far too alarming.”