Article content

In the most precise study yet on vegetation growth trends across North America, researchers from America’s space agency have found that nearly a third of the land cover in Canada and Alaska has greened in recent decades as a result of climate change.

We apologize, but this video has failed to load.

tap here to see other videos from our team. Try refreshing your browser, or Canada's tundra is turning green — and its Boreal forest brown — NASA study finds Back to video

The researchers also found that, while vegetation productivity is on the rise in the tundra regions of the continent, warming temperatures might be having the opposite effect on the Boreal forest, which showed some signs of browning. Overall, three per cent of the land experienced vegetation decline.

The researchers used data from NASA’s Landsat satellites between 1984 and 2012 in order to trace wide-scale changes over the 10.6 million sq-km landscape. Areas characterized by growth – where grasslands became shrublands, or where existing shrublands became bigger and denser – were classified as greening, while those where vegetation declined were classified as browning.

Scott Goetz, deputy director and senior scientist at the Woods Hole Research Center in Massachusetts, said the study shows “a clear distinction” between what’s happening in the tundra and Boreal regions of Canada and Alaska.

“Whereas temperature limited tundra regions have almost ubiquitously increased productivity with warming temperatures . . . trees in the boreal system do not respond well to high temperatures,” he wrote in an email to the National Post.