EITA, TARAWA, KIRIBATI – 2015/09/30: A young boy stands on a narrow strip of land that luckily didn’t flood and prevented his home from being drowned in the sea with the village Eita.
The people of Kiribati are under pressure to relocate due to sea level rise. Each year, the sea level rises by about half an inch. Though this may not sound like much, it is a big deal considering the islands are only a few feet above sea level, which puts them at risk of flooding and sea swells.
It is well agreeable that the people of Kiribati account for little to nothing in terms of green house emissions but are forced to face the direct consequences of global warming. And with an average age of 22, Kiribati’s future generations are at risk of potentially lethal sea level rise. (Photo by Jonas Gratzer/LightRocket via Getty Images)

By Andrew Freedman for Mashable

If humanity’s current business-as-usual path of global warming pollution continues, enough long-term sea level rise could be “locked in” by melting ice sheets — on the order of about 8.9 meters, or 29 feet, to submerge land that more than half a billion people call home, according to a new report.

If, on the other hand, warming were limited to 3.6 degrees Fahrenheit, or 2 degrees Celsius, compared to preindustrial levels, this would cut the population threatened by long-term global sea level rise in half, the report found.

Watch: How climate change affects the world’s most vulnerable people

The study, from the climate research and journalism group Climate Central, found that during the next few centuries, sea level rise could threaten the existence of entire cities, and in some cases, whole countries, depending on the decisions made in the next couple of years regarding cuts in greenhouse gas emissions.