As Climate Changes, Species Must Race across Landscape to Adapt

The scientific journal Nature a few weeks ago (24 December 2009) published an important and interesting letter on the rapid pace of climate change -- and the rate at which species must move across the landscape just to remain within the same temperature conditions as these shift away from them. Two of the coauthors, Chris Field and Scott Loarie of Stanford University, explain in a short video.

In The Velocity of Climate Change, the authors develop an index of temperature change for the 21st century that "represents the instantaneous local velocity along Earth's surface needed to maintain constant temperatures."  The global mean is 0.42 km (a quarter mile) each year, though the velocity varies with topography and habitat.  The slowest velocities are in mountainous areas (because elevation -- and lower temperatures -- can be reached over a shorter distance) and the fastest velocities are in flat areas such as grasslands, deserts and coastal areas.

"Expressed as velocities, climate-change projections connect directly to survival prospects for plants and animals," says Chris Field in a Stanford University press release. "These are the conditions that will set the stage, whether species move or cope in place."

"You can think of it as a kind of sprinting capacity that these plants and animals need if they're going to stay in the climate zone that they're in now,” Field says in a companion piece (Editor's Summary: A Race Against Climate Change) in Nature.

Unfortunately, many species cannot naturally move as fast as will be required.  "We project that large areas of the globe (28.8%) will require velocities faster than the more optimistic plant migration estimates from a landscape before anthropogenic fragmentation," the authors say.  Furthermore, the necessary migration will require many species within existing protected areas to move well beyond the boundaries of those areas.  According to the study, only 8% of the world's protected areas are large enough to accommodate within their borders the migrations suggested by the study for this century.

"In landscapes where small velocities are required, moderate-sized protected areas may be able to contain moving climates and ecosystems," the report says.  "Elsewhere, further steps must be taken. These include slowing the temporal gradient of climate change through reduced emissions, increasing the ability of plants and animals to disperse through managed relocation, or increasing the size of protected areas through habitat corridors and new reserves."

Online Resources:

• New $2 Million Network to Help Threatened Ecosystems and Societies Adapt to the Impacts of Climate Change.  Press release (3 Feb 2009) from WWF.
• Climate change puts ecosystems on the run. Press release (24 Dec 2009) from Stanford University. 
• The velocity of climate change.  By S.R. Loarie, P.B. Duffy, H. Hamilton, G.P. Asner, C.B. Field, D.D. Ackerly.  Published in Nature, 24 December 2009; 462 (7276): 1052-5.  See also:
  •  Editor's Summary: A Race Against Climate Change, Nature, 24 December 2009.
  • Making the paper: Scott Loarie & Christopher Field, Nature, 24 December 2009.