The global sea level rise accelerated in the 20th century compared to the past 2,800 years according to an international research team. Two papers published in the Proceedings of the National Academy of Sciences journal build a clear case for man-made global warming contributing to the accelerated pace of sea level rise.
The scientific team gathered data corresponding to two dozen locations worldwide. The various data was processed to result into several charts showing sea level rise and decline over millennia. As per the findings of the scientific endeavor, sea levels rose by an average of 1.5 inches per century until booming industrialization was on the rise in the 1880.
Slowly, the rising rate accelerated. In the 20th century, the global sea level rise reached 5.5 inches. The year 1993 was a landmark for global sea level rise, with the rate increased to approximately one foot per century.
According to the papers’ findings, projected sea levels by 2100 could rise by 11 to 52 inches. The results depend on the different scenarios taking into account the trapping or removing of greenhouse gas emissions from the atmosphere or the lack of these processes thereof. Bob Koop, a Rutgers professor of earth and planetary scientist declared:
“There’s no question that the 20th century is the fastest. It’s because of the temperature increase in the 20th century which has been driven by fossil fuel use”.
The scientific team looked at data collected from salt marshes as well as other locations on the coast. A complex set of data offered clues to the difference in sea levels across centuries. The team looked at everything that could offer more insight on sea level rise or declines. Single cell organisms, mangroves, sediments and corals have been helpful to complete the puzzle.
The resulting figures were checked with markers such as the increase in lead levels as the industrial era advanced. Isotopes were also measured as they are representative for the ascent of the atomic era.
Before the industrial age, the global sea level followed a downward trend. As the industrial age promoted the large-scale extraction and use of fossil fuels and other polluting resources, the global sea level rise accelerated in the 20th century.
Currently, sea level rise is expected to follow an upward curve provided greenhouse gas emissions aren’t contained. If the global sea level increased by another 22 inches under a business as usual scenario, coastal communities and not only are facing a real threat. A 22-inch increase is among the most optimistic estimates.
Other scenarios have yielded a global sea level rise of 52 inches by 2100. However, in light of the 2015 Paris climate agreement and the individual nations’ pledges, sea level rise might be contained between 11 and 22 inches by the end of this century.
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