BOULDER, Colo., April 22 (UPI) -- Earth's climate zones are shifting and being repositioned at an accelerating pace with global warming, a U.S. study says.
Scientists at the Cooperative Institute for Research in Environmental Sciences, a joint venture between the University of Colorado Boulder and the National Oceanic and Atmospheric Administration, report the acceleration of change means species inhabiting each zone have less time to adapt to climatic changes than thought.
The Earth has more than 30 distinct climate zones, areas defined by annual and seasonal cycles of temperature and precipitation, as well as temperature and precipitation thresholds of plant species.
"The warmer the climate gets, the faster the climate zones are shifting," Irina Mahlstein at NOAA's Earth System Research Laboratory in Boulder said. "This could make it harder for plants and animals to adjust."
"A shift in the climate zone is probably a better measure of 'reality' for living systems, more so than changing temperature by a degree or precipitation by a centimeter," she said.
The researchers used climate model simulations and an ecosystem classification scheme to look at the shifts between climate zones over a two-century period, 1900 to 2098.
For an initial 3.6 degrees Fahrenheit of warming, about 5 percent of Earth's land area shifts to a new climate zone, the researchers said, and with the next 3.6 degrees an additional 10 percent would shift.