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OPINIONS

Weather or not

You don’t have to know me well to know that I don’t like deer. It’s been too many years since I watched Bambi and too few since I last walked through a forest whose next generation of seedlings had been devoured by an overpopulation of deer. And when it comes to the choice between doe-eyed ruminants and baby trees, well, I tend to side with the baby trees.

But there is one species of deer that warms my heart every time I see it: The Florida Key Deer, whose miniature size and disproportionate boldness could endear it to even the coldest heart.

And, if the climate models are to be believed, the Key deer might not be around for long enough to cause much ecological harm, anyway.

As its name suggests, the Key deer is a denizen of the Florida Keys, the string of low-lying islands arcing into the Caribbean off the southern tip of the Sunshine State. A vacation-goer’s paradise for their umbrella drinks and ample watersports, the Keys are also something of a homeowner’s nightmare because their low-lying coastal properties are frequently awash in hurricane storm surges.

These periodic inundations are likely to become more frequent with human-driven climate change. Human carbon dioxide emissions trap sun energy within Earth’s atmosphere, slowly warming the planet. This leads to sea level rise for two reasons. First, warmer water takes up more space, so the oceans — which are warming alongside the atmosphere — are expanding. Second, warmer global temperatures lead to melting of glaciers and ice sheets, releasing once-frozen water back into the ocean and further raising sea surface levels.

All this means that the Florida Keys — where 90 percent of land is within five feet of the present-day sea level — are at major risk. And, along with billions of dollars in coastal property, the Key deer’s habitat could soon be sinking underwater.

So the Key deer, squeezed onto tinier and tinier fragments of land, is likely to become one of the most obvious — though hardly unique — victims of anthropogenic climate change. Many other species, unable to reach a new habitat as their existing ones become too salty, too hot or too dry, will face a similar fate.

That is, unless we choose to save them.

Even if we fail to deal with climate change, managed relocation — physically distributing members of at-risk species to new, potentially suitable habitats — could help at least a few species escape extinction. But both the scientific feasibility of relocation and the ethical implications remain unknown.

From a scientific perspective, predicting a species’ future home range is no simple task. Climate envelope models (CEMs) attempt to match what we know about an organism’s biology (i.e., the temperature at which an alligator egg should incubate or the amount of rainfall a plant requires) with what we predict about future climate regimes. Though CEMs are the best tools we have at the moment, they’ve been roundly criticized for their heavy burden of uncertainty. And managers are especially leery of risking rare conservation dollars and rarer species members on a wild goose chase for a future habitat.

On the other side of the coin, managed relocation represents a new direction in conservation thinking. While it’s easy to operate from a “preservationist” perspective — trying to leave Nature relatively undamaged by human activity; doing some remediation and setting aside parks and preserves — managed relocation is inherently an “interventionist” approach that involves deliberate human modifications to an environment by adding in a new species. And, as we know from an abundance of experience with invasive species, such additions, whether intentional or accidental, may have major negative consequences. An attempt to save one species could unhinge an entire ecosystem.

These caveats haven’t stopped either conservation groups or resource managers from going ahead with some relocations, however. And really, such relocations aren’t so different from the myriad of species introductions humankind has done throughout the course of our highly migratory history. We are the great planetary homogenizers, bringing our favorite food crops, pets, landscaping trees and livestock with us where we go. Plenty of pestilential hangers-on (like rats and mosquitoes) have come along for the ride, too.

Just as in the past, these deliberate species introductions will be done based on human wants and desires. Species will be saved in proportion to their charisma (think doe-eyed Key deer) and economic utility (think Tasmanian crayfish and Pacific Northwest forestry). We may try to employ some scientific methods to increase our probability of success, but in the end decisions will be made based on human self-interest, not ecological foresight. And the rest of the species, critical though they may be to ecosystem functioning, will be left behind to weather the storm.

 

Holly looks forward to weathering reader opinions and feedback via email at hollyvm “at” stanford.edu.

About Holly Moeller

Holly is a Ph.D. student in Ecology and Evolution, with interests that range from marine microbes to trees and mushrooms to the future of human life on this swiftly tilting planet. She's been writing "Seeing Green" since 2007, and still hasn't run out of environmental issues to cover, so to stay sane she goes for long runs, communes with redwood trees and does yoga (badly).
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