Climate change is causing an extensive greening in parts of Alaska and Canada, a new NASA study found.
A research team from NASA analyzed 87,000 images taken from 1984 to 2012 by its Landsat satellites. The analysis displayed a changing landscape. In particular, they found that areas in western Alaska, northern Quebec and other northern regions are turning green.
This suggested that the Arctic temperatures are warming faster compared with other places on the planet. It also suggested that the Arctic region is changing.
Apart from having longer growing seasons, the soils in the region are also experiencing changes. Canada's tundra is now growing shrubbery, while the existing ones are growing much thicker.
The analysis found that there is an "extensive greening" activity in the tundras of Quebec, western Alaska, Labrador and on Canada's northern coast. The research team also discovered that Canada's northern forests greened by approximately 29.4 percent. On the other hand, the ones in Alaska declined by about 2.9 percent.
The effects of these environmental changes are not yet fully understood. However, there is a growing evidence that the changes can disturb the carbon cycle.
"It shows the climate impact on vegetation in the high latitudes," said researcher Jeffrey Masek, who is also NASA's Landsat 9 project scientist at the Goddard Space Flight Center.
According to Scott Goetz, Woods Hole Research Center's deputy director, the research showed "a clear distinction" between the changes in Alaska and Canada's boreal and tundra regions.
"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," Goetz said in an email.
The findings were published in the Remote Sensing of Environment journal in April. The discoveries supported past studies on the vegetation changes in North America's boreal and Arctic regions.
Masek said that past studies looked into these changes, but the satellite images they used were much coarser. Past studies utilized images taken by NASA's Moderate-resolution Imaging Spectroradiometer (MODIS) satellites and Advanced Very High Resolution Radiometer (AVHRR).
In the Landsat study, they were able to confirm findings of the previously published studies using satellite images with improved resolution. As a result, the researchers were able to better analyze the inconsistencies across the landscapes.
Masek added that the study provided a sneak peek on how the warming climate is changing the global vegetation patterns. The new findings can help scientists to better understand how the local climates are affecting the browning and greening trends in particular regions.
Photo: Mike Beauregard | Flickr
