Global warming will cause plants and animals to migrate
A new study estimates that animals and plants will have to migrate, on average, nearly a quarter of a mile each year to keep up with shifting climate belts caused by global warming.
One upon a time, adaptation to global warming was dubbed a cop-out, a way to duck the challenge of reducing, and ultimately eliminating, greenhouse-gas emissions from cars, factories, and power plants.Skip to next paragraph
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Now, however, the issue is front and center – a necessary adjunct to reducing emissions. One significant adaptation challenge involves protecting as much of Earth's biodiversity as possible in what is projected to be a prolonged period of rapid – if sometimes erratic – warming.
Enter Scott Loarie. a researcher at the Carnegie Institution's department of global ecology in Stanford, Calif. He and five colleagues have unveiled a new approach to assessing how changing climate will affect various habitats. They dub the measure "climate velocity."
The measure takes into account changing temperatures as broad climate zones migrate north and south away from the equator, and hike their way up the sides of mountains. And it looks at the geographic setting in which the habitats appear -- whether on a broad flat landscape or in mountains, for instance.
One broad observation from the data: plants and animals that live in broad, relatively flat areas – the Great Plains, regions containing mangrove forests, or the African Veldt – are likely to have the toughest time dealing with global warming.
Organisms living there must migrate or have their seeds dispersed over long distances to keep up with climate belts that are moving more rapidly than many species can match. This is especially true for plants and animals that live in patchy, geographically small protected areas. Habitats are fragmented, often with no "corridors" connecting them to allow for easy migration.
Plants and animals in mountain regions, on the other hand, appear to face a lower risk of being overtaken by global warming, because mountains exhibit large temperature swings with altitude; it's a fairly short walk or flight up-slope to reach a more hospitable climate zone. The exception: organisms that live on mountain summits and have nowhere else to go.
The work Dr. Loarie and his colleagues have done is adding a new tool to conservationists' quiver, says the University of Maryland's David Inouye, who heads the graduate program in sustainable development and conservation biology there.
"It gives an idea of how quickly changes are going to be happening and where they are going to be happening most rapidly," he says during a phone chat.
Land managers -- from officials at the state level to federal managers with the US National Park Service and the Bureau of Land Management -- increasingly are asking where their scarce conservation dollars can be put to most effective use at a time when global warming is changing the rules of the game.
Loarie's research team is providing a fresh way to do that, Dr. Inouye says.
For years, researchers have been trying to figure out how plants and animals would respond to global warming. But Loarie and his colleagues decided to ask the question from a different perspective: "What is the landscape's potential to buffer these changes?"
"It's really going from sounding the alarm over climate change to really trying to say: Look, some change is going to happen. How do we adapt to that change?" he explains.
The key, he says, is the speed of change.
To estimate that, the team used the Intergovernmental Panel on Climate Change's business-as-usual emissions scenario as the basis for tracking the pace of warming through 2100. Then they applied that to various habitats and even protected areas around the globe to get a sense for how quickly the climate regimes over these areas would be expected to change.