Greening continues across Arctic ecosystems

Aug. 21 (UPI) — Thanks to new satellite data and improved modeling, scientists have a better understanding of how the Arctic’s vegetation responds — and will respond — to warming trends.

As global temperatures continue to rise, especially in the Arctic, the polar region’s ecosystems are getting greener. But until now, scientists hadn’t studied the greening phenomena in detail.

To plot changes in Arctic vegetation, scientists used 30 years of satellite data collected by the National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer. Researchers compared the high-resolution data with advanced climate models, designed for the Coupled Model Intercomparison Project Phase 5.

The analysis revealed what scientists expected. As the Arctic warmed, tree and plant growth accelerated. But the satellite data showed climate models underestimated the Arctic’s greening phenomena.

The new findings — detailed in the journal Nature Climate Change — revealed 16 percent decline in land where vegetation growth is limited by cold temperature. In other words, lots of vegetation previously limited by ice, snow and frigid temperatures now enjoys an uninhibited growing season.

“Our findings suggest that CMIP5’s predictions may have significantly underestimated changes in the Arctic ecosystem, and climate models will need to be improved to better understand and predict the future of the Arctic,” Trevor Keenan, climate scientist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, said in a news release.

The new data — detailed in the journal Nature Climate Change this week — helped scientists design more accurate predictive models. The improved simulations suggest only 20 percent of Earth’s vegetated land will be significantly curtailed by cold temperatures by the end of the century.

“Although the greening might sound like good news as it means more carbon uptake and biomass production, it represents a major disruption to the delicate balance in cold ecosystems,” said Keenan. “Temperatures will warm sufficiently so that new species of trees could move in and compete with vegetation that had previously dominated the landscape. This change in vegetation would also affect insects and animals that relied on native vegetation for food.”

Researchers say more work must be done to understand how shifts in vegetation will change Arctic ecosystems, and how these changes will impact Earth’s climate. Warmer waters in the Arctic have already begun to disrupt marine ecosystems.