A study published Monday warned sea levels could rise by more than two meters (about 6.6 feet) by the end of the century due to climate change, which would swamp coastal cities.
The authors of a study published in the Proceedings of the National Academy of Sciences concluded it was "plausible" that sea level rising could exceed two meters, potentially resulting in the displacement of up to 187 million people and significant land loss in "critical regions of food production."
"A SLR [sea level rise] of this magnitude would clearly have profound consequences for humanity," the team concluded.
Lead author Jonathan Bamber said coastal cities are the most at-risk including cities in Florida, Louisiana and California, according to USA Today.
Across the world, “such a rise in global sea level could result in a land loss of almost 700,000 square miles," he said, according to the news outlet.
The United Nations climate panel's most recent major report in 2013 projected that sea level rise would be between 52 and 98 cm (20.4 to 38.5 inches) in 2100, according to CNN, which noted that some experts found the UN panel's finding to be conservative.
Speaking with CNN, Bamber characterized the new findings as "grim."
"Two meters is not a good scenario," he said.