Scientists with Rutgers University claim sea levels are rising faster now than in the last 2,700 years. After looking at climate data going back 3,000 years, they concluded that ocean levels will continue to rise at an alarming rate and global warming is the cause.
“We can say with 95 percent probability that the 20th-century rise was faster than any of the previous 27 centuries,” said lead researcher Bob Kopp.
Sea levels will continue to rise no matter what humans do
The study, published in the Proceedings of the National Academy of Sciences, indicates ocean levels rose around 14 centimeters (5.5 inches) from 1900 to 2000.
Recent data released by NASA suggest levels are still rising at an accelerated pace, increasing at 3.4 millimeters per year.The team of scientists thinks that if the planet had not been on a warming trend, it's unlikely the ocean would have risen so much in the last hundred years. They predict the sea level change would have been anywhere from a three centimeter fall to a seven centimeter rise.
“It’s not the tide. It’s not the wind. It’s us. That’s true for most of the coastal floods we now experience,” said Benjamin H. Strauss, another researcher.
The researchers speculate that sea levels will continue rising regardless of the amount of carbon dioxide released into the atmosphere. However, choices humans make will still make a difference.The data forecasts a level rise between 24 and 61 centimeters should the amount of carbon dioxide emitted be reduced.
In contrast, an increase in emissions could lead to a rise of as much as 131 centimeters, or nearly 4.3 feet.
By the 22nd century, many cities on the coasts will be abandoned as sea levels will continue to rise. Over thousands of years, humans have benefited from stable sea levels, allowing for the growth of large coastal cities.
That is about to change, according to climate scientists.
“I think we can definitely be confident that sea-level rise is going to continue to accelerate if there’s further warming, which inevitably there will be,” said Stefan Rahmstorf, a professor of ocean physics at the Potsdam Institute for Climate Impact Research in Germany.
Global temperature linked to sea level
In the 20th century, the melting of mountain glaciers and the natural expansion of ocean water as it warms were the major factors in the rising sea levels. However, in the next 100 years, the scientists believe the ice sheets that cover Greenland and Antarctica will have a greater role to play.The new study is a much larger look at previous research done by the same authors. In 2011, they measured the ocean and climate records of several salt marshes in North Carolina and discovered a sea level rise in the last 100 years as well.
To get a global picture of the changes, the new data is a reconstruction of past sea levels from 24 locations across the Earth.
Additionally, more recent measurements were taken from 66 global tide gauges. Other factors, including whether land is rising or sinking as well as the changes in ocean currents, were also calculated and taken into account.The ocean is sensitive to small changes in the Earth’s temperature. According to the data, ocean levels dropped almost three inches when global temperatures cooled during the Middle Ages. Yet, when temperatures rose again, so did sea levels.The study seems to link global warming to the rise in sea level. The scientists concluded that climate change caused by humans was to blame for three quarters of the coastal floods recorded from 2005 to 2014.
“Physics tells us that sea-level change and temperature change should go hand-in-hand,” Dr. Kopp said. “This new geological record confirms it.”
