Trump's Wall Won't Stop Climate Change Migrants from Streaming into the US

This story is part of VICE's ongoing look at how climate change will have altered the world by the year 2050. Read more about the project here.

By 2050, white Americans will likely be outnumbered by nonwhites. Donald Trump's anti-immigration policies will have succeeded or failed. A wall may or may not be straddling the US-Mexico border. But that will be small potatoes in light of the devastation climate change will have wrought on Latin America's ability to grow food and the migration that will result. Displaced by rising temperatures, millions of people will have only one logical direction to go: north.

"All other things being equal, if you change the climate to make it less favorable in Mexico, you're going to see more of an inclination to move to the United States," said Michael Oppenheimer, Princeton professor of geoscience and international affairs.

In 2003, the Pentagon's Office of Net Assessment commissioned a report on the possible national security implications of abrupt climate change. The authors of the report, the futurists Peter Schwartz and Doug Randall, made one particularly prescient prediction:

Trump is decidedly attempting to turn the US into a "fortress." But walls won't stop migrants made desperate by worsening conditions. Latin America is home to many farmers, a group that will be particularly affected by climate change. According to the CIA World Factbook, farmers make up 13.4 percent of Mexico's labor force, as well as 31.2 percent of Guatemala's and 27.8 percent of Ecuador's; by comparison, only 0.7 percent of the US population works in the agriculture sector. According to Columbia University's 2009 report on climate change and immigration, drier times are coming for Latin America. By 2080, it says that "runoff in the region will likely decline by at least 5 percent and possibly up to 50 percent, with declines getting progressively worse in the semiarid and arid north." Much of that dryness will have likely taken hold by 2050.

The precise, numerical relationship between migration and climate is still uncertain. Oppenheimer co-wrote a somewhat famous 2010 paper on the topic concluding that 1.4 to 6.7 million Mexican adults would have to relocate by 2080. The math in that paper received something of a pummeling from the peer-review process and in turn a healthy dose of scorn from the climate change denier community. But Oppenheimer published again in 2012, thanking the scientists who spotted the oversight, and arguing that when analysts observe crop yields, temperature change, and immigration data, they'll still see clear "evidence of a climate-migration relationship."

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Others, like the sociologist Raphael J. Nawrotzki of the Minnesota Population Center, have tried to quantify the exact connection and came away hesitant to make a numerical forecast. Last year, Nawrotzki concluded that, among other problems, "data limitations prevented us to account for the influence of broader contextual factors (e.g., structural and institutional)." But like Oppenheimer, he cited "empirical evidence that in some countries, such as Mexico, adverse climate change may strongly increase international migration."

The broader point is that it's pretty safe to project that drier weather, along with the projected 0.8–2.6 Celsius degree global increase in temperature expected by 2050 according to the Intergovernmental Panel on Climate Change, will make farming a lot more difficult in Latin America (among many other places). And that, consequently, will cause people to pull up stakes and find more favorable conditions.

Does that mean they'll come flooding into the US? That's also a safe bet. "What we'll see in terms of migration is going to come about as a result of the US economy and US needs," said Lorenzo Cano of the Center for Mexican-American Studies at the University of Houston. As the Great Recession demonstrated, the pace of Latin American immigration is indeed tied to economic conditions in the US. According to Cano, "although short-distance, internal migration is a frequent response to environmental change, international migration is likely in the aftermath of droughts, particularly in places with well-established migratory traditions."

As migration to the US becomes more popular, the trip will get more dangerous. The prospect of passing through hundreds of miles of desert along migratory corridors like the one in the Pima Desert, between Nogales in Mexico and Tucson, gets deadlier when temperatures rise. At least 100 bodies get found in that area every year, and as cities like Phoenix turn into postapocalyptic nightmarescapes of unliveable heat, that number isn't likely to decrease.

Predicting this migration is relatively straightforward, but the political consequences of this movement of people are trickier to sort out. According to a Pew report from last year, Latinos are settling in places like North Dakota and Pennsylvania in record numbers, a trend that shook up locals in these previously relatively homogenous communities and ostensibly scared them into voting Trump, according to one hypothesis advanced in a New York Times article.

Meanwhile, climate patterns in 2050 could devastate agriculture in places like California, making the move from Latin America to some parts of the US less appealing. As a 2016 article in Pacific Standard by Jeremy Miller pointed out, the drought in California has decimated the region's agriculture sector for the past few years, driving migrant laborers into the Pacific Northwest. "Would the Oregon state line become like the US-Mexico border?" Miller wondered.

Still, according to Oppenheimer, immigration isn't all about the US being awesome. The US will also just be an escape. "You have to remember that one of the functions of migration across the US border is to relieve the social pressure in Mexico," he told me.

Currently, a great number of companies—including some owned by Trump—take advantage of the H-2B visa program, which brings unskilled guest workers to enter the US to do jobs Americans are unwilling or unable to do. The Republicans who are in charge of the US government seem prepared to scale back this program, but even if it remains robust until 2050, there will likely be lots of Latin Americans who won't be allowed to legally enter the US, creating political problems south of the border.

"If Mexicans are not allowed to come here," Cano told me, "the unrest in Oaxaca, Mexico City, and other places is going to crystallize into a much more radical movement. It will be much more populist and much more left of center than what we've seen in Mexico."

Throughout history, outbreaks of violence in Mexico have driven refugees over the border legally as well—including a flood of refugees from the drug wars. The War of Independence in the early 20th century resulted in political immigration, Cano told me, "including my grandparents who came here to get away from the fighting."

But undocumented workers are generally not looking for a new home. According to Cano, "for the most part, people have come, and then they have returned." Often migrant laborers show up when there's opportunity and slip back into their home country when the time is right. One side effect of building a wall, Cano said, is that "now they're just staying because of border enforcement."

But if they need to eat and faming in their homeland is no longer possible, as Cano told me, "You can't stop them."

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