Climate Change to Cause Sea Levels to Rise 20 Feet: Coastal Cities at Risk

Sea-level rise is a huge issue for coastal landmasses across the world. Now, a new review reveals that global sea levels have risen at least 20 feet above present levels on multiple occasions over the past three million years. Yet the temperatures that caused this massive increase were only a 1 to 2-degree increase of degrees in Celsius.

"Studies have shown that both the Greenland and Antarctic ice sheets contributed significantly to this sea level rise above modern levels," said Anders Carlson, one of the researchers, in a news release. "Modern atmospheric carbon dioxide levels are today equivalent to those about three million years ago, when sea level was at least six meters higher because the ice sheets were greatly reduced."

The review actually summarized more than 30 years of research on past changes in ice sheets and sea level. It revealed that changes in Earth's climate and sea level are closely inked, with only small amounts of warming needed to have a significant effect on sea levels.

"The ominous aspect is that CO2 levels are continuing to rise, so we are entering uncharted territory," said Peter Clark, one of the researchers. "What is not as certain is the time frame, which is less well-constrained. We could be talking many centuries to a few millennia to see the full impact of melting ice sheets."

Coastal cities have experienced enormous growth in population and infrastructure. As sea levels rise, this could be catastrophic to these populations. Surges caused by storms could swamp cities if sea-levels were 20 feet higher in the future.

"The influence of rising oceans is even greater than the overall amount of sea level rise because of storm surge, erosion and inundation," said Carlson. "The impact could be enormous."

The findings are published in the journal Science.

Related Stories

Glacial Earthquakes Help Scientists Track Massive Ice Loss in Greenland

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).