Across the globe, plants and animals are creeping, crawling, slithering and winging to higher altitudes and higher latitudes as global temperatures climb.
The greater the warming in any given region, the farther its plants and animals have migrated, according to the largest analysis to date of the shifting ranges of species in Europe, North America, Chile and Malaysia.
About 2,000 species examined are moving away from the equator at an average rate of more than 15 feet per day, about a mile per year, according to new research, published Thursday in the journal Science, which analyzed previous studies. Species are also moving up mountains to escape the heat, but more slowly, averaging about 4 feet a year.
"The speed is an important issue," said Chris Thomas, the study's main author and a conservation biologist at the University of York in England. "It is faster than we thought."
Included in the analysis was a 2003 study that found species moving north at a rate of just more than a third of a mile per year and up at a rate of 2 feet a year. Camille Parmesan of the University of Texas, who conducted that study, said the new research makes sense because her data ended around the late 1990s and the 2000s were far hotter.
As the temperatures soared in the 2000s, the species studied moved faster to cooler places. The comma butterfly in Great Britain has moved more than 135 miles in 21 years, Thomas said. He found that the further north the species live, the faster they moved their home base. In general, northern regions are warming more than those closer to the equator.
Stanford University biologist Terry Root, who wasn't part of the study, pointed to another species, the American pika, a rabbitlike creature that has been studied in Yellowstone National Park for more than a century. The pika didn't go higher than 7,800 feet in 1900, but in 2004 they were seen at 9,500 feet, she said.
Federal weather data show the last decade was the hottest on record, and 2010 tied with 2005 for the hottest year on record.
Associated Press, Washington Post