Along with drowning polar bears and melting glaciers, global warming is enacting another astonishing change on the arctic landscape. The vegetation at the earth's northernmost latitudes now resembles that found 250 to 430 miles south. "Ecologically off limits" only a few decades ago, an area the size of the continental United States is now green with new vegetation.
While the northwards march of lower-latitude ecosystems may seem great at first glance, it's actually contributing to what's called an amplified greenhouse effect. Darker forests absorb more energy from the sun than white snow, while the melting of the permafrost releases methane and CO2, two major greenhouse gases. Good news for anyone looking to invest in Arctic farmland, bad news for everyone else.