Environment News Service: Five scientists from the New York-based Wildlife Conservation Society had to evacuate their remote field camp in northern Alaska because of a new kind of threat brought on by global warming – a polar bear stranded on land. Polar bears would normally be out on sea ice this time of year, the WCS says, but with recent warming the ice is miles from shore and bears are becoming increasingly trapped on land well away from their prey of seals. “It is ironic that our efforts to …