A new research has showed that a global warming rise of less than 2C is more than enough to increase sea levels by 20 feet. Researchers have said that such a rise in sea levels have taken place many times in the past three million years.

The rise in temperature on each occasion had accounted for 1C to 2C. The researchers have warned that lack of actions to limit emissions will increase global temperatures by 4C or even 5C above industrial levels by 2100.

The researchers have expressed worries over sea level rise and said that rise of 20 feet of sea level than what they are today would have devastating effects on hundreds of millions of people living in highly populated coastal regions of the world.

“The ominous aspect to this is that carbon dioxide (CO2) levels are continuing to rise, so we are entering uncharted territory. What is not as certain is the time frame, which is less well-constrained”, said Dr. Peter Clark, one of the study authors from Oregon State University (OSU) in the US.

Dr. Anders Carlson, another member of the OSU team, whose findings are in the journal Science, said the impact of rising oceans is much more than the overall amount of sea level rise because of storm surge, erosion and inundation.

According to him, there is not much difference between atmospheric carbon dioxide levels today and what they were three millions years ago.