Sea levels are rising at an unprecedented rate, much faster than had been observed in the past two millennia, as a new study shows. The output of the seas of the coast is closely linked with the historical temperature data, suggesting that the warmer the planet gets, the more sea level rise.
"Sea level rise is a potentially disastrous outcome of climate change," - said in their particulars study researcher Benjamin Horton (Benjamin Horton) from the University of Pennsylvania. "Rising temperatures melt land-based glaciers and warmed ocean waters."
Sea level rise may carry considerable risk coastal cities, with 50 percent of the U.S. population lives within 50 miles (80 kilometers) from the coast. The higher sea levels will rise, the harder it will be the situation for the cities, and more impressive erosions will be subject to the coast, according to the information of researchers.
The research team has restored all the changes of sea-level East Coast U.S. for the past 2000 years on the basis of micro minerals (typical of animals that lived in the oceans) found in the depths of the marsh soil in North Carolina.
The results showed high seas for specific years, which they then compared with measurements of the tides in the past 300 years. They found that sea levels were stable from about 200 BC to AD 1000, with a slight increase of 0.02 inches (0.5 millimeters) per year over 400 years.
After this increase, the sea level was considered stable during the 19th century. Next, sea levels began to rise again, and the increase is, on average, was equal to 0.08 inches (2 millimeters) per year. This is the most significant increase, which the research team noted in their records that go back more than 2,100 years ago.
They then compared these data with records of historical temperatures. First, they drew attention to the rise in sea level that occurred in the 11th century, coinciding with the period of warming, known as the Medieval Climate Anomaly. Current sea level rise, it seems, is also the same as the temperature changes.
The data will help researchers to understand climate change on Earth and in the oceans, in the context of historical change. It may also help researchers predict how sea levels will rise with the onset of higher global temperatures.
"Scenarios of future increases depend on understanding the response of sea level to climate change" - said one of the researchers analyzing Camp Andrew (Andrew Kemp) from Yale University. "Accurate estimation of sea level changes in the past provided the basis for such predictions."
The analysis was published this week in the journal "Proceedings of the National Academy of Sciences".
Original: LiveScience Translation: M. Potter