Immigration could become a very heated subject by the end of the century. A new paper from Cornell University estimates that some 2 billion people may be forced out of their homes by rising ocean levels by 2100, and looking for a home which populations inland may not be prepared or willing to offer.

Homeless man.

Image credits: Avi Chomotovski.

We’re already struggling to rise to the challenge of one immigration crisis caused by the civil war in Syria. And if I may get a personal opinion in, we’re not doing very well at all. The Syrian refugee exodus has divided European sentiment, more often due to propaganda and feeling than facts and figures, and has seen countries in the Middle East shun those in need and close off their borders. All of it generated huge — and for the most part avoidable — human suffering and misery.

But even it pales in comparison to what Charles Geisler, professor emeritus of development sociology at Cornell, says is in store for us by the end of the century. With Earth’s population recently breaking the 7.5 billion mark and rising rapidly, there’s a lot more people living today than there have ever before. But we’re also set to have less land than before on which those people can live.

Climate change, coastal change

“We’re going to have more people on less land and sooner that we think,” said Geisler, who was also lead author of the paper. “The future rise in global mean sea level probably won’t be gradual. Yet few policy makers are taking stock of the significant barriers to entry that coastal climate refugees, like other refugees, will encounter when they migrate to higher ground.”

The current inhabitants will be forced to seek new places to live in — according to the paper, there could be as many as 1.4 billion climate refugees by 2060 and 2 billion by 2100. And all those people won’t be competing for the same resources as are available now. Feeding and housing the 10 billion people the UN estimates will call Earth home by 2050 will take a lot of high-quality arable land and retail space, while rising ocean levels will be eating into fertile coastal zones and river deltas. Another issue is that the new low-elevation coastal areas we’ll be left with will be battered by more violent storms which will push sea water further inland, where it will disrupt agricultural activity and reduce the overall habitability of the area.

In their paper, the team gives preliminary estimates of the areas which are unlikely to support incoming climate refugees due to several factors such as “residues of war, exhausted natural resources, declining net primary productivity, desertification, urban sprawl, land concentration, ‘paving the planet’ with roads, and greenhouse gas storage zones offsetting permafrost melt.” In a worse-case scenario, the team believes that the competition over reduced space will lead to land-use trade-offs. It’s probable that we’ll see public land sold off for human settlement, and violent conflicts are also very likely to pop up.

But it also shows that there are measures we can take to alleviate both the effect of rising oceans and to ease the burden on the refugees. For example, officials in Florida, the state which can boast the USA’s second-longest coastline, have actually planned for a coastal exodus according to Geisler, in the form of the state’s Comprehensive Planning Act. China is also taking steps to prepare for an eventual flooding of its coastlines.

However, as the old adage goes, an ounce of prevention equals a pound of cure.

“The pressure is on us to contain greenhouse gas emissions at present levels. It’s the best ‘future proofing’ against climate change, sea level rise and the catastrophic consequences likely to play out on coasts, as well as inland in the future,” said Geisler.

The full paper “Impediments to inland resettlement under conditions of accelerated sea level rise” has been published in the journal Land Use Policy.