PLEA Network

4 June 2016, Climate News Network, Warming turns northern tundra green. Rising temperatures are creating longer Arctic growing seasons and increasing the risk of carbon escaping into the atmosphere from the thawing permafrost.  The northern edge of North America is getting steadily greener. In the most detailed study so far of plant growth across Alaska and Canada, scientists say that about a third of the land cover now looks less like tundra, and more like a warmer ecosystem. The researchers report in the Journal of Remote Sensing that examination of 87,000 images captured by the NASA Landsat satellite reveals that Alaska, Quebec and other regions became greener between 1984 and 2012. Landsat, a project also backed by the US Geological Survey (USGS), provides the longest space-based record of land vegetation in existence. Growing in size “The greening trend was unmistakable,” the scientists report. In Canada, northern forests tended to become greener, although if anything they declined in Alaska. Overall, 29.4% of the region became greener, and only 2.9% declined. The Arctic is the fastest-warming region of the northern hemisphere, with longer growing seasons and thawing permafrost. The scientists saw grassy tundra convert to shrubland, and shrubs grow in size and density, and such changes will inevitably start to play into water, energy and carbon cycles. Read More here