By Alister Doyle, Environment Correspondent
OSLO (Reuters) - Trees in the Arctic region may grow 500 km (300 miles) further north by 2100 as climate change greens the barren tundra and causes sweeping change to wildlife, a leading expert said.
A quickening melt of snow, ice and permafrost will enable more southerly species such as pine trees or animals such as foxes to move north.
"Changes seem to be happening even more rapidly than we had anticipated just 10 years ago," Aevar Petersen, chair of the Conservation of Arctic Flora and Fauna (CAFF), told Reuters from Greenland on Thursday, where foreign ministers of Arctic countries agreed steps to bolster regional cooperation.
"Scientists estimate the treeline could move 500 km north by 2100 from now," he said, based on CAFF projections. If that happened, as much as half the Arctic tundra from Siberia to Canada could vanish.
In some places, southerly evergreen shrubs were taking over from grasses, mosses and lichens typical of tundra. "The tree line is moving north quite rapidly," he said.
CAFF is backed by the Arctic Council, comprising the United States, Russia, Canada and the five Nordic nations.
Other experts say timber firms such as Stora Enso or Abitibi may not benefit from climate change. Better growth conditions may also bring more pests and forest fires.
Warming in the Arctic is happening about twice as fast as in the rest of the world. As reflective snow and ice recede, they expose soil or water which are a darker color and so soak up more of the sun's heat.
Polar bears are among those under threat from an accelerating melt of sea ice.
"We do fear for the polar bear if the ice is melting," Petersen said. "It really hasn't anywhere to go." An international report last week projected that the Arctic Ocean could be ice-free in summers in the next 30 to 40 years.
Foreign ministers from the Arctic Council agreed to step up cooperation and signed a deal splitting responsibilities for search and rescue as the region becomes more accessible to shipping, mining and oil and gas exploration.
A CAFF study showed that wildlife species in the high Arctic were generally in decline while those slightly to the south were increasing. On land, many cannot move north if temperatures warm because they face the barrier of the Arctic Ocean.
Millions of shorebirds, such as the red knot which migrates as far as Australia or South Africa, build nests on the ground in the high Arctic. Their eggs and chicks will be extremely vulnerable to predators such as foxes if the region warms.
