Climate Change Pushes Species Up and North

A meta-study in the journal Science says – changing global temperatures are pushing species towards the poles and higher altitudes.

A meta study is a study that rounds up all the other related studies (in this case 54) and analyzes them for trends or patterns that emerge. After looking at the scientific literature on species migration for the last 40 years, it appears that animals and plants are responding to a changing climate by moving further north and to higher elevations.

While it may sound strange that trees are picking up and moving in essence that’s what’s happening. Of course, they can’t uproot themselves and walk up a mountain or further north to a more suitable climate. But researchers have found that 2,000 species of plants and animals are finding new homes thanks to climate change.

And the rate at which the they are moving to a more suitable climate is staggering, much faster than the commonly accepted rates found in the scientific literature.

Chris Thomas, Biology professor at the University of York in England and the meta study project leader says, “These changes are equivalent to animals and plants shifting away from the equator at around 20 centimeters [8 inches] per hour, for every hour of the day, for every day of the year.”

That’s a rate three times faster than scientists thought plants and animals were migrating because of climate change. That amounts to a shift of 10.1 miles to the north per decade. And species are moving higher up hills and mountains as well at a rate twice what scientists thought. On average species are moving at a rate of 36.1 feet higher per decade.

While it may not sound like a lot of movement Dr. Thomas says that there is no other explanation why plants and animals would be permanently shifting their habitats to higher latitudes and higher elevation. He also says the speed at which the change is occurring is very dramatic.

I-Ching Chen, another lead researcher on the meta study says this project shows that global warming is pushing plant and animal species toward the poles and to higher elevations. Dr. Chen says, “We have for the first time shown that the amount by which the distributions of species have changed is correlated with the amount the climate has changed in that region.”

This analysis of the literature spells trouble for animals in Arctic regions where the climate is warming twice as fast as anywhere else. There is nowhere for these species to go. The same holds true for plants that are already perched on mountain tops. They can’t climb any higher.

Dr. Thomas and other scientists fear that many of the species that are unable to adapt by shifting their homes will simply die out.

The meta study focused on the scientific literature in Europe and North America, leaving a gaping hole in what’s happening in equatorial regions, where temperatures are warming much more slowly than higher latitudes. In the tropics moisture not temperature may be having the same overall effect on species. That’s the subject for another meta study.

And while the overall trend pointed toward a warming world forcing the migration of plants and animals toward the poles and to highter elevations, a significant minority of species moved to lower latitudes and lower elevations. Dr. Thomas attributes this to other pressures that have an effect on species distribution. Habitat loss, land use, and other pressures besides climate change do have an impact on species movement.

He told the New York Times, “Land use change, habitat loss — there’s a long list of pressures which must all be balanced. Climate change is a huge pressure, but it’s just one pressure facing species around the world.”