To better understand the climate dynamics associated with the increase in growth in the northwestern Eurasian tundra, he and colleagues studied information from the herdsmen's observations, temperature data, growth rings in the wood of shrubs and satellite data, including observations of the amount of green covering the landscape during the growing season.
Were the treelike shrubs to become widespread, this change could exacerbate global warming through what is known as the albedo effect, he said. When snow falls on the tundra's shrubs, it creates a continuous white blanket that reflects the sun's energy back out into space. Trees, however, rise above the snow, breaking up the white and darkening the land surface. As a result, less energy is reflected back into space and more is absorbed, resulting in warming.