Some 800,000 years ago, the Earth’s climate cooled, and huge glaciers invaded what is now the Western United States. Areas once teeming with life became uninhabitable to many species. But most of them weren’t driven to extinction. Instead, prehistoric climate refugees migrated to regions that for one reason or another were buffered from the cold and the ice — from the Southwestern desert lowlands to sheltered, temperate nooks in the Pacific Northwest.
When most of the glaciers finally receded for good about 12,000 years ago, the floral and faunal refugees slowly made their way back to their ancestral homelands and settled in their current ranges. The natural sanctuaries had served as a sort of temporal ark, ferrying myriad creatures across the Ice Age.
Now, as human-caused climate change warms the planet, many species are likely, once again, to seek out refugia — areas shielded from warming temperatures and associated effects that can shelter the next generation of climate refugees from heat, fire and extreme weather and thereby help protect biodiversity. Scientists are now eagerly identifying and mapping these places — and pushing policymakers to prioritize their preservation — in order to keep them from being destroyed by development or overuse.
They have their work cut out for them. In a study published in Frontiers in Ecology and the Environment in January, researchers found that only a small fraction of climate refugia are currently protected in the U.S., though the Biden administration’s campaign to conserve 30% of U.S. lands by 2030 offers hope of saving more. Private, as well as public, lands need to be protected.
Preserving refugia alone won’t be enough; further warming must also be kept in check. As temperatures continue to climb, fewer and fewer places will be safe from global warming’s calamitous effects. And many species might suffer the same fate as the woolly mammoth did: Unable to escape from rising temperatures and increasing moisture when the last Ice Age ended, the cold-weather giant and many other megafauna vanished from the Earth forever.
Hannah Agosta/High Country News
SOURCES: “Integrating climate-change refugia into 30 by 30 conservation planning in North America” by Sarah P. Saunders and Joanna Grand et al; “Managing Climate Change Refugia for Climate Adaptation,” by T.L. Morelli et al; “Late Quaternary dynamics of Arctic biota from ancient environmental genomics,” by Y. Wang et al; “Past Climate and Vegetation Changes in the Southwestern United States,” by R. Thompson and K. Anderson; “Of glaciers and refugia: a decade of study sheds new light on the phylogeography of northwestern North America,” by A.B.A. Shafer et al; Audubon; U.S. Forest Service; U.S. Geological Survey; INSTAAR; Refugia Research Coalition.
Jonathan Thompson is a contributing editor at High Country News. He is the author of Sagebrush Empire: How a Remote Utah County Became the Battlefront of American Public Lands.
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