Sea levels on Earth are rising many times faster than in the past 2,800 years and are increasing because of man-made global warming, according to new studies.
An international team of scientists charted the rising and falling seas over centuries in two dozen locations across the globe. Until the 1880s and the world's industrialization, the fastest sea rise was about 1 to 1.5 inches a century, plus or minus a bit. But in the 20th century the world's sea rise was 5.5 inches.
Two different studies that featured on Monday in the journal Proceedings of the National Academy of Sciences, said by 2100 the world's oceans will escalate between 11 to 52 inches, depending on how much heat-trapping gases are emitted by Earth's industries and vehicles.
Sea level upsurge in the 20th century is mostly man-made, the study authors said. A different, not-yet-published study by Kopp and others found that since 1950, about two-thirds of the U.S. coastal floods in 27 locations have the impressions of man-made warming.
The Kopp study and a separate one circulated by another team estimated future sea level rise based on various methods. They derived the same general estimates, despite using different methods, said Anders Levermann, a co-author of the second paper and a researcher at the Potsdam Institute.
If greenhouse gas pollution carries on at the current speed, both studies project rise of about 22 to 52 inches. If countries follow the treaty agreed upon last year in Paris and limit further warming, sea level rise would be in the range of 11 to 22 inch.