A new study from Cornell University revealed that about one-fifth of the global population, or an estimated 2 billion people worldwide, will be forced to resettle of go deeper inland by 2100 due to the continuous rise in sea levels.

The study, published in the journal Land Use Policy, showed that blooming global population could make the matter worst. The researchers estimated that there are about 1.4 billion "climate change refugees" in the world by 2060 and by 2100 the number of the displaced people due to rising sea levels could reach up to two billion.

"We're going to have more people on less land and sooner that we think," said lead author Charles Geisler, professor emeritus of development sociology at Cornell, in a press release. "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."

For the study, the researchers reviewed potential problems that climate change refugees may face if they go deeper inland. The researchers identified these land impediments to relocation using three organizing clusters, which include depletion zones, win-lose zones and no-trespass zones. By doing so, the researchers were able to provide preliminary estimates of their toll on inland resettlement space.

The researchers found that some inland regions were unlikely to support new waves of climate change refugees due to the residues of war, declining net primary productivity, desertification, urban sprawl, road developments, land concentration and exhausted natural resources. Additionally, some inland regions have greenhouse gas storage zones offsetting permafrost melt, making them unlikely to hold resettlement.

Aside from the rising sea levels, increasing intensity of storm surge and the booming global population are also having a huge influence in the numbers of climate change refugees. Storm surge can push seawater further inland. On the other hand, the upward trend of the global population requires more arable land even as the ocean swallows up fertile coastal zones and the river deltas. These force people to search for new places to dwell or migrate to a higher ground.