Not only humans but four-legged migrants are at risk from border walls. Other species can be climate refugees too.
LONDON, 17 February 2021 − Something there is, wrote the American poet Robert Frost, “that does not love a wall.” Thanks to British researchers we now know that something is the white-lipped peccary, the jaguar and the southern spotted skunk. All of them − and many other species − could be affected by border walls like that separating the US from Mexico.
The barrier between India and Myanmar, too, creates problems for the sloth bear, the Indian pangolin and the large spotted civet. And a fence along the Sino-Russian borders could be hard on the desert hare, the Tibetan antelope, the goitered gazelle and the Tibetan fox. When things become harsh on one side of the wall, none of them can move to a better home.
Which could be bad news because, as the planet heats up, and regional climate zones begin to shift, around one in three mammals and birds could by 2070 be forced to look for more welcoming habitat in another country.
Around 3,200 kilometres of man-made barrier now extend along national boundaries, precisely to prevent the unauthorised movement of refugees. But those same barriers could create problems for some of the 700 or so mammals that may have to shift home as regional climates change, according to a study in the Proceedings of the National Academy of Sciences.
The US-Mexican border wall alone could obstruct the migration of 122 species of four-legged animal refugee.
“If we are serious about protecting nature, reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue”
“Species all across the planet are on the move as they respond to a changing climate. Our findings show how important it is that species can move across national boundaries through connected habitats in order to cope with this change,” said Stephen Willis of Durham University in the UK.
“Borders that are fortified with walls and fences pose a serious threat to any species that can’t get across them. If we are serious about protecting nature, expanding transboundary conservation initiatives and reducing the impacts of border barriers on species will be really important − although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue.”
Professor Willis and his colleagues started from the premise that the effectiveness of conservation action is not separable from what they call “underlying sociopolitical factors.”
There has, for more than a decade, been serious concern that climate change and human population expansion could ultimately lead to a mass extinction of wild creatures.
But mathematical models of the natural niches occupied by birds and mammals worldwide show that the biggest losses of native species will be in those countries with weaker governance and lower Gross Domestic Product.
And the disappearance of mammals in particular will be in those countries with the lowest levels of the greenhouse gas emissions that fuel climate change.
To survive, many of those species will have to migrate − and at that point, walls and fences designed to exclude human migrants will become major obstacles to the conservation of the wild things. The margay and the common opossum, the Mexican wolf and that wild cat the jaguarundi could all be turned back, along with hungry and near-desperate families, at the US-Mexican border.
“The stark inequities between those who contributed most to climate change and those who will be most impacted raise really important questions of international justice,” said Mark Titley, a researcher at Durham who led the study.
“Fortunately, our models also show how strong and urgent emissions reductions, in line with the Paris Agreement, could greatly reduce the impacts on biodiversity and relieve the burden of such losses on less wealthy nations.”
Or, as Robert Frost put it:
“Before I built a wall I’d ask to know What I was walling in or walling out…”
− Climate News Network