Europe is facing its biggest refugee crisis since World War II. What is new this time around is that many of the displaced are being driven from their homes by the destructive effects of climate change. And this is just the beginning.

As sea levels rise, swallowing island nations and swamping large parts of Bangladesh, and as droughts trigger food shortages across much of the global South, the refugee crisis will only worsen. And we can expect that Europe's right-wing parties will respond by doubling down on their already-potent anti-immigrant rhetoric with a push to seal off the borders.

Pundits on the left denounce this as a craven, mean-spirited stance towards those who are suffering the most from our collective climate crisis. And they're right: opening the borders to climate refugees is a matter of basic justice. We need to devise policies to ensure that all have the right to access safe and habitable parts of the planet we share.

But there is something more to be said here. An open border policy may also be the key to stopping climate change itself.

Scientists tell us that on our present trajectory we have only a 5 percent chance of keeping global warming below the danger threshold of 2 degrees, as our addiction to endlessly expanding economic growth and consumption is swiftly wiping out the gains we're making through technology and renewable energy. As a recent op-ed in the New York Times put it, "The climate crisis? It's capitalism, stupid." We need a new economic system - one that does not require this mad rush up an exponential curve - but our leaders are unwilling to take that step. There is a yawning gap between the threat posed by climate breakdown and how little we are doing to address it.

This is a puzzle. Why are we so willing to gamble thus with the fate of human civilization, with 95 percent certainty of catastrophe? Is it that we're in denial? Are we just repressing a reality that's too traumatic to confront? Yes, probably. But it's also something much simpler: a geography problem.

The great irony of global warming is that its causes and consequences are inversely distributed. The rich nations of the global North are responsible for 70 percent of historical CO2 emissions, but they bear only about 18 percent of the total costs. It's the South that takes the hit: according to the Climate Vulnerability Monitor, the global South loses nearly $600bn each year due to drought, floods, landslides, storms and wildfires. As climate change worsens, their losses will reach a staggering $1 trillion per year by 2030.

And then there's the human toll. Global warming claims some 400,000 lives each year worldwide - many due to extreme weather events but most due to climate change-induced hunger and disease (pdf). Only 2 percent of these deaths occur in the North. The South suffers the rest, and the vast majority of climate mortality occurs in the countries with the lowest carbon emissions in the world.

Yes, Britain has its floods, southern Europe its droughts, and the United States its hurricanes. But as devastating as these are for ordinary people's lives, those governments have so far absorbed the costs and kept chugging along with the status quo - more growth, more consumption, more emissions, more capitalism. They are not acting on climate change because they have no real reason to care. The consequences of their industrial over-consumption are harming lands far beyond their borders.

It's a textbook case of moral hazard: they are willing to take the risk because someone else bears the cost. Of course, eventually, this will change. They will get serious when their coastal cities flood and their food imports dry up - but by then it will be too late.

The solution is simple, at least conceptually: open the borders. By tearing down the walls that separate the causes and consequences of climate change we can force a more honest reckoning with reality. Once the victims of climate change have the right to seek refuge in Europe and North America, it will obliterate the moral hazard of global warming. As rich nations finally start to feel the heat, so to speak, you can bet they'll act fast, doing everything in their power to ensure that people's home regions remain livable. Even if it means pushing for a new, more ecological, economic model.

This might seem unrealistic at a time of rising anti-immigrant sentiment. But either we do it now, finding orderly ways to integrate climate refugees and allowing ourselves to be spurred to action by the suffering we're forced to confront, or down the road, we're going to face a refugee crisis more severe, violent and destabilising than anything we can imagine. We have a choice.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial stance.