When it comes to wildlife and global warming, we've been worrying over the obvious victims: The polar bears and alpine songbirds that will watch their habitat melt, leaving them no place to go.
But a new study raises alarm about the wildlife living in the world's warmest regions, the tropics.
"In the tropics, most of the organisms we have studied, from insects to amphibians and reptiles, are already living at their optimal physiological temperatures," said Curtis Deutsch, UCLA assistant professor of atmospheric and oceanic sciences and co-author of the new study, co-authored with University of Washington scientists and published in Proceedings of the National Academy of Sciences. "When warming starts, they do less well as they move toward the hottest end of their comfort range. Even a modest increase in temperature appears rather large to them and negatively impacts their population growth rates."
Because the tropics hold the world's most abundant and diverse life, the findings add weight to the notion that the Earth will see a massive die-off of species akin to past episodes of mass extinctions in the geologic record. This extinction, of course, is caused largely by humans and the pollution from the burning of fossil fuels that is changing the atmosphere.
Insects, frogs and other cold-blooded creatures were the focus of the research, since those creatures rely on the environment to regulate their body temperatures. Because these creatures are so sensitive to their environments, even a small change in temperature can have an outsize effect.
"Our results imply that in the absence of any adaptation or migration by these populations in the tropics, they will experience large declines in their population growth rate," Deutsch said. "This could lead to a fairly rapid population collapse, but organisms are adaptable; the question is, what will their response be? They could migrate toward the poles or toward higher elevations, for instance."
Enter your city or zip code to get your local temperature and air quality and find local green food and recycling resources near you.