News that climate change is poised to wreak havoc on the world's food supply, leading to widespread famines and resulting mass migrations, should raise alarms throughout the Western world — and not just because the prospect of a spike in suffering and death around the globe is deeply upsetting in itself. It should also provoke unease because a world in which tens or even hundreds of millions of people are forced to migrate in search of food is also a world in which the far right is likely to flourish.

This runs contrary to conventional wisdom on the left and in the center of the political spectrum. The left tends to assume that as the effects of climate change — rising temperatures, massive floods, intensifying storms, persistent droughts leading to desertification — are more widely felt, pressure to act will build, benefitting progressive parties and politicians. Many American centrists — including an influential faction on the center-right — agree that this logic will imperil the electoral prospects of the Republican Party. With young people overwhelmingly convinced of the reality of anthropogenic climate change and strongly supportive of policies to halt and reverse it, this faction assumes the left will benefit as the consequences worsen.

But this fails to account for the domestic political consequences of mass migration.

Far-right parties had already begun to increase their vote share across Europe prior to the arrival in 2015 of well over a million asylum seekers, spurred on by drought, poverty, and violence, from Syria, Libya, South Sudan, and Afghanistan. But once these migrants showed up on the doorsteps of the European Union and German Chancellor Angela Merkel declared that Germany would not limit the number of refugees accepted into the country (an open door that many feared would allow access to other EU member states, and encourage further waves of arrivals), the far right surged — and it hasn't abated, even though the migrant crisis has receded for now.

A world in which many times the number of migrants from Africa, the Middle East, and South Asia are forced to flee their homes in search of food is exceedingly unlikely to produce a diametrically opposite political response. On the contrary, it's overwhelmingly likely to produce a very similar response, though on a vastly greater scale. That's because the scale of the coming migration crisis is likely to be vastly greater.

According to The New York Times summary of a United Nations report issued on Thursday, "a half-billion people already live in places turning into desert, and soil is being lost between 10 and 100 times faster than it is forming." A half-billion people is … a lot of people. If even a small fraction of them end up traveling to Europe in search of refuge, not to mention better economic prospects more generally, the political consequences will be enormous. Either parties of the left and center will be driven by their moral commitments to support opening the continent's doors to these migrants, leading to a massive surge for far-right parties willing to take a stand against such humanitarian generosity — or most of the parties will recognize the need to take a similar stand out of electoral self-preservation, transforming continental politics in a nativist direction overnight.

When it comes, this shift will be driven primarily by public opinion. Right-wing movements benefit from fear, and the prospect of throngs of poor and needy migrants requesting entry to Western countries, especially when these migrants look different and act and worship in a different way than these countries' majorities, is a scary thought to many. Critics may be right to judge this a severe moral failing, but describing it as such won't make the feeling go away — especially when right-wing demagogues are sure to do everything they can to intensify and exploit them for political gain. Those who oppose the lurch toward xenophobia won't stand a chance amidst the maelstrom.

The same process will take place in the United States. Migration to the U.S. through Mexico from Central American countries has already surged, contributing to the chaos on the southern border in recent months — and helping to bolster Donald Trump's base of support on the nativist right. As the Times article on the UN report notes, this follows a previous spike earlier in the decade that was likely an early "signal of climate change": "Between 2010 and 2015 the number of migrants from El Salvador, Guatemala, and Honduras showing up at the United States' border with Mexico increased fivefold, coinciding with a dry period that left many with not enough food."

What is likely to happen in domestic political terms when and if worsening climate change leads to an exponential increase in the number of Central American migrants showing up at U.S. ports of entry? The question answers itself. If nativist xenophobia is a fire presently burning through one of America's two parties, a massive surge of additional migrants from the south would be fuel that ensures its rapid spread throughout the country and its political culture.

What about the left's call to combat climate change preemptively, before it reaches catastrophic levels of disruption and loss? Won't that fuel an equal and opposite progressive surge at the ballot box? Not necessarily. The more the left indicates that it finds borders morally suspect, as it is doing quite strongly at the moment, the less the electorate is likely to trust progressives with political power in a time of intense migratory pressures. Then there is the unpopularity of politicians promising to inflict pain on the electorate, which is what would be required to cut emissions meaningfully enough to slow down, let alone reverse, climate change.

As I argued in May, democracies are notoriously bad at making hard choices — and whether to accept slower growth, sharply higher costs, and dramatically increased environmental regulations on the basis of scientific probabilities and predictions is one of the hardest choices of all. Responding to bad events that have already happened is far easier, and that's likely to be the right's approach. With each new flood, drought, and storm, Republicans will react by offering to help clean up the mess while doing little to forestall future environmental shocks. It's an approach that just might work politically, especially if it's combined with tough, far-right border restrictions that keep out the flood of refugees from the south. That will enable the GOP to portray itself as a party working above all to protect the country and its prosperity in a time of heightened adversity.

Add it all up and we're left with multiple signs that a world enduring climate change could be one in which the far-right thrives as never before.