And yes—climate change is definitely going to re-shape the planet’s plant and animal communities.
By Nathan Collins
View of the Great Plains near Lincoln, Nebraska. (Photo: Wikimedia Commons)
Climate change is likely to do a lot more than just increase our air conditioning bills and raise our sea levels. The re-shuffling of plant and animal communities ranks among the most widely accepted (though still little-understood) eventualities of a warming Earth. Now, researchers have mapped out where that re-shuffling is most likely—a necessary first step for anyone looking to preserve precious biodiversity.
“[N]ovel species assemblages are likely to be forming in the North American Great Plains and temperate forests, Amazon, South American grasslands, Australia, boreal Asia and Africa,” climate scientists Alejandro Ordonez, John Williams, and Jens-Christian Svenning write in Nature Climate Change. In those regions (and others), new climates may emerge, and, in some cases, changing profiles of rain and temperature may pull different plants and animals in different directions, ultimately re-shaping how those species interact.
The team focuses on three mechanisms most probable to affect plant and animal habitats. First, climate change is likely to open new habitats and close others—for example, some mammals have already begun moving to higher elevations, where possible, to adjust to warming environments. Second, plants and animals are likely to respond to climate change at different rates. Third, species vary to which climate variables they’re most sensitive. Put those ideas together and it’s a recipe for a jumbled, complicated mess.
“Being able to identify how and where these changes can generate new species assemblages has important implications for conservation.”
To sort it all out, Ordonez, Williams, and Svenning collected temperature and precipitation data from 1901 to 2013 from the Climatic Research Unit at the University of East Anglia. Then, they mapped out how much both variables changed over the past century around the globe, along with the direction of that change. To understand what’s meant by “direction of change,” don’t think about how the temperature changes in a particular spot. Instead, think about the place where the temperature is typically, say, 70 degrees Fahrenheit. As the planet warms, that region will move north. Complicating the analysis, temperature, and precipitation may move in different directions.
The data suggest that the most novel environments have emerged in polar and tropical areas, especially Greenland, the northern end of South America, central Africa, and western China. Meanwhile, climate movement is happening faster than some species can handle, but slower than others can, meaning that some species will be able to adapt while others are left behind.
Finally, there are a great many places around the world where the movement of rainfall and temperature are in opposite directions, which means some plants and animals won’t be able to find the mix of temperature and precipitation they’re used to. That may explain some of the odder climate migrations scientists have witnessed, such as tree habitats moving downhill despite increased temperatures.
“As the effects of climate change are likely to intensify, being able to identify how and where these changes can generate new species assemblages has important implications for conservation,” the researchers write. For example, where climate change’s effects are felt the strongest, it might be best to prioritize physically moving species to more hospitable climates.