Washington - Arabstoday
NASA image shows 41% increase in plant growth across region
The Arctic is becoming lusher and greener as temperatures rise, new images from NASA reveal.
“Vegetation growth at Earth's northern latitudes increasingly resembles lusher
latitudes to the south” the agency said after releasing a new study based on a 30-year record of land surface and newly improved satellite data sets.
The images show how the extreme of the Northern Hemisphere, previously frozen areas, is now changing and showing lush green grass and trees growing.
NASA scientists examined the relationship between changes in surface temperature and vegetation growth in the Artic.
“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,” said Ranga Myneni of Boston University's Department of Earth and Environment.
“In the north's Arctic and boreal areas, the characteristics of the seasons are changing, leading to great disruptions for plants and related ecosystems.”
As a result of enhanced warming and a longer growing season, large patches of vigorously productive vegetation now span a third of the northern landscape, or more than 3.5 million square miles (9 million square kilometers).
That is an area about equal to the contiguous United States.
An amplified greenhouse effect is driving the changes, according to Myneni. Increased concentrations of heat-trapping gasses, such as water vapor, carbon dioxide and methane, cause Earth's surface, ocean and lower atmosphere to warm.
Warming reduces the extent of polar sea ice and snow cover, and, in turn, the darker ocean and land surfaces absorb more solar energy, thus further heating the air above them.
“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.”