Global warming is making the Arctic literally greener.
University and NASA scientists studied how warmer temperatures affected plant growth in the Arctic. They found that rising temperatures have resulted in vegetation levels typical of more southern locations.
The team studied temperature and vegetation growth from 45 degrees north latitude to the the Arctic Ocean. As it turns out, vegetation at these latitudes is similar to that found at 4 to 6 degrees (250-430 miles) south in 1982.
“Higher northern latitudes are getting warmer, Arctic sea ice and the duration of snow cover are diminishing, the growing season is getting longer and plants are growing more,” Ranga Myneni of Boston University’s Department of Earth and Environment said on NASA’s website. “In the north’s Arctic and boreal areas, the characteristics of the seasons are changing, leading to great disruptions for plants and related ecosystems.”
This increased green presence comes in the form of trees and tall shrubs. “Large patches of vigorously productive vegetation now span a third of the northern landscape, or more than 3.5 million square miles,” NASA wrote. This span of vegetation in the Arctic is equal to the size of the continental United States. The increase is larger on the Eurasian side than on the North American side.
“It’s like Winnipeg, Manitoba, moving to Minneapolis-Saint Paul in only 30 years,” said Compton Tucker, an author of the study at NASA’s Goddard Space Flight Center in Greenbelt, Md., of the temperature shift. For a comparison that doesn’t only involve very cold cities, that’s about the same distance between New York City and Athens, Ga.
What’s causing the shift? NASA points to an “amplified greenhouse effect.” As we release more heat-trapping gases, like water vapor, methane and carbon dioxide, into the atmosphere, these gases warm the ocean, Earth’s surface and the lower atmosphere. This causes polar ice to melt. When oceans’ “white” ice is replaced with melted sea water, the dark water absorbs more solar energy, heating up the region even more.
“This sets in motion a cycle of positive reinforcement between warming and loss of sea ice and snow cover, which we call the amplified greenhouse effect,” Myneni said. “The greenhouse effect could be further amplified in the future as soils in the north thaw, releasing potentially significant amounts of carbon dioxide and methane.”
This green bloom may not last, though. The team points out that in addition to more plant life, these higher temperatures can also lead to droughts, forest fires and pest infestations, which could offset the extra greenery
