Global warming isn't just a threat to polar bears in the rapidly warming Arctic, a new study says: Species in the tropics are beginning to feel the effects as well, and it will only get worse. Researchers surveyed more than 1,900 species of plants, insects, and fungi in a Costa Rica rainforest and came to the troubling conclusion that if world temperatures continue to rise as predicted over the next 50 years, half of those species will have to move to completely new territory to find an appropriate habitat. The situation is complicated for tropical species, says lead researcher Robert Colwell; shifting north or south doesn't bring significantly lower temperatures, so species will have to take up residence at higher altitudes to survive.
In the absence of mountainsides to serve as a cool refuge, those plants and insects that cannot face higher temperatures may disappear as it would require migrations ...
