Border Patrol agents talk with migrants seeking asylum as they...

Border Patrol agents talk with migrants seeking asylum as they prepare to transport them for processing near Dulzura, California, on June 5. Waiting to fight the migration problem until it shows up at the border is also dangerously impractical. Credit: AP/Gregory Bull

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners. Mark Gongloff is a Bloomberg Opinion editor and columnist covering climate change. He previously worked for Fortune.com, the Huffington Post and the Wall Street Journal.

Gardi Sugdub is a tiny island off Panama’s Caribbean coast that is jammed from end to end with housing for about 1,300 members of the indigenous Guna people. The island is sinking beneath rising waters as the planet warms. So Panama has built an inland housing development for the entire population. They’ll move into their pristine new homes this month.

If only all climate migration could be so simple.

President Joe Biden signed an executive order last week making it harder for people to seek asylum at the U.S.-Mexico border, the latest gambit in a political war over immigration that has divided the country for decades. But as with many effects of a changing climate, we might someday look back on the era that gave us routine election-year migrant-caravan panic and Donald Trump’s big, beautiful wall as “the good old days.”

As temperatures rise around the globe, so will heat waves, droughts, floods, pandemics and other natural disasters along with shortages of food and water and conflicts over resources. By the nightmare logic of climate change, the countries least responsible for pumping greenhouse gases into the atmosphere and heating the planet will bear the brunt of these impacts. And such countries also tend to have the least wealth, infrastructure and social fabric to protect their people.

In fact, after just 1.3 degrees Celsius of global warming over preindustrial averages, the countries with the most refugees, asylum seekers and other uprooted people already tend to be among those deepest in the jaws of climate change.

These are mostly clustered in sub-Saharan Africa, South Asia and South America along an equatorial belt that has experienced more climate-change-induced extreme heat than the rest of the planet in recent decades.

Most migrants likely wouldn’t say they’re fleeing climate change. They’re escaping war, economic uncertainty, social instability and the like. But climate change multiplies those threats. It’s probably not a coincidence that 95% of conflict refugees in 2020 came from global-warming hot spots, according to the UN High Commission for Refugees.

With so many different factors influencing why people move, it can be tough to single out climate. There are some clues, however. A recent review of the scientific literature by researchers at the University of Vermont and the University of Otago in New Zealand found that high temperatures and weather-related disasters consistently trigger migration around the globe. And a 2021 study by researchers at the National Autonomous University of Mexico found the movement of low-income farmers from Mexico to the U.S. not only tripled during times of drought but accounted for possibly a third of all cross-border migration.

Given all the complexities and the lack of data, it’s even harder to model potential future climate migration. Various algorithms have cranked out global numbers anywhere from 50 million to 1.2 billion. There could be 216 million people displaced within national borders by 2050, the World Bank has estimated. And internal migration — say from the country to the city — is usually the first step in cross-border migration. Up to 6.7 million people could flee Latin America for the U.S. alone because of climate change by 2080, according to a 2010 Princeton study.

But there’s not much use in trying to gauge such distant numbers with precision. It’s more than enough to know they’ll probably be very high — especially considering the extreme backlash even the relatively small amount of cross-border migration in recent decades has already caused.

We talk constantly in the U.S. about the “crisis at the border,” but as my Bloomberg Opinion colleague Justin Fox has noted, illegal southern-border crossings are almost certainly not worse now than they were in, say, the 1980s and ’90s. Encounters between migrants and border officials are at all-time highs, but those officials have become much, much better at capturing illegal immigrants in recent years. The result is a real problem but not necessarily a generational one — yet.

It’s easy to imagine the political response in this country when the number of encounters doubles or triples. But simply adding higher walls and more razor wire can’t be the only answer. For one thing, it’s immoral. The U.S. and other developed countries are responsible for the vast bulk of the greenhouse gases that have warmed the atmosphere and immiserated millions. They bear significant responsibility for cleaning up the mess they have made.

Waiting to fight the migration problem until it shows up at the border is also dangerously impractical. Trapping hundreds of millions of people in unlivable conditions will only build up impossible pressures that result in even more chaos and conflict. It will be far cheaper in dollars and lives to support these people before they leave home, especially by helping their countries mitigate and adapt to climate change. The politics of doing this are difficult now, but they won’t get any easier in the future.

Of course, there’s some $70 billion per year’s worth of low-hanging fruit here: That’s the annual cost of servicing developing-nation debt, which can be canceled or worked off in debt-for-nature swaps to alleviate the burden on vulnerable countries. Developed nations should also keep living up to their long-delayed promise to spend $100 billion a year on climate aid — without resorting to tricks such as providing most “aid” in the form of more debt or requiring the proceeds to be funneled back to donor countries.

Climate migrants also deserve full protection under international law, along with a recognition that pulling up and leaving for greener pastures is not a crime but a tool of survival and adaptation that humans have used for as long as there have been humans. As the number of climate safe havens dwindle, it helps to remember that eventually the climate migrants could be us.

—With assistance from Elaine He.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners. Mark Gongloff is a Bloomberg Opinion editor and columnist covering climate change. He previously worked for Fortune.com, the Huffington Post and the Wall Street Journal.

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