Burning all the fossil fuels will increase global temperatures by 20 degrees Fahrenheit, which is enough to melt the entire Antarctic ice sheet and cause the sea level rise of up to 160 feet, according to a new study, Reuters reports.

Scientists say half of the Antarctic ice sheet can melt in as quickly as a thousand years, with sea levels rising to as much as one foot every 10 years. Land ice in other parts of the world will also melt. The rate at which the entirety of Antarctica's ice would melt stunned the scientists, who used to believe the process would take 10,000 years.

"To be blunt: If we burn it all, we melt it all," lead study author Ricarda Winkelmann, researcher at the Potsdam Institute for Climate Impact Research in Germany, told the New York Times.

As global temperature increases, the expanding warming waters will cause the sea levels to rise further, causing the total sea level rise to increase by 200 feet.

When this happens, U.S. cities like New York, Miami, Houston, Washington, D.C., and New Orleans will be under water, the study says. Cities in other countries like Sydney, Tokyo, Paris, Amsterdam, Venice, London, Beijing and Rome will be lost as well, according to the scientists.

"If we don't stop dumping our waste carbon dioxide into the sky, land that is now home to more than a billion people will one day be under water," study co-author Ken Caldeira of the U.S. Carnegie Institution said, according to Reuters.

The scientists noted that the sea level prediction for the next century remains the same, totalling to only about three feet or less. However, after that time period, half of the Antarctic ice sheet will start to melt and there will be far graver problems than rising sea levels, according to the study.

"This is humanity as a geologic force," Caldeira said. "We're not a subtle influence on the climate system - we are really hitting it with a hammer."

The study was published in the Sept. 11 issue of the journal Science Advances.