Science

Rising Sea Level Highest in Nearly 3,000 Years

The 20th-century saw a rise in the Earth’s sea levels that scientists believe didn’t occur anytime in the last 3,000 and that the 20th Century was “extremely likely” to have seen sea levels rise more than the entirety of the same period.

Rising Sea Level Highest in Nearly 3,000 Years

Scientists announce their findings on Sea Level

“We can say with 95 percent probability that the 20th-century rise was faster than any of the previous 27 centuries,” said Bob Kopp, a climate scientist at Rutgers University who led the research who along with others from universities around the world that contributed to the team of 10.

He quickly points out that it’s unlikely that sea levels rose more than this in 3,000 years, but that his team couldn’t say this with the same level of accuracy.

The study that featured the team’s findings was published yesterday in the Proceedings of the National Academy of Sciences.

It should come as no surprise that the team’s blames global warming and the burning of fossil fuels for the 14 centimeters the sea rose from 1900 to 2000 which equates to 1.4 millimeters each year. NASA, however, thinks that this has been greatly increased recently and is convinced that the number, at present, is something more in line with 3.4 millimeters each year with no slowing being observed.

The work by this team suggests a “hockey stick” graph where sea levels largely remain flat thousands of years before a spike or “blade” that shows a sharp rise.

21st Century to improve?

Absolutely not. Despite a fairly impressive deal being put in Place in Paris in December, that is a long ways from where we are at, if (and that’s no given) all the signers comply with the carbon neutral accord. The 21st century is likely to see a rise somewhere between 24 and 61 centimeters with the Paris deal taken into effect. If countries don’t comply and Paris is, effectively, rubbished you’re looking at a rise of as much as 4.25 feet…goodbye to Miami and others.

But a century is a long time, “We have a model that’s calibrated against a period when a certain set of processes, largely thermal expansion and glaciers, were dominant,” he says, “and we’re looking forward to a period when other factors will be dominant,” says Kopp.

The largest factors in sea level rise observed in the 20th century was the melting of glaciers around the globe and the ability of the ocean to expand when warmer. However, Greenland’s and Antarctica’s ice shelves are melting rapidly but this wasn’t really wasn’t the case in the 20th century. Depending on how much they melt will be a major factor in 21st Century sea levels.

The new study does not exist in a vacuum, but rather, reiterates what a 2011 study of salt marshes in North Carolina concluded.

Michael Mann of Penn State University, who along with two colleagues, first coined the “hockey stick” reference in 2011 says that this week’s study simply showed an “incremental advance” on his team’s findings.

Mann recently told the Washington Post by email that:

The study nonetheless reiterates the conclusion we reached [in 2011] that the acceleration in sea level rise over the past century is unprecedented over at least the past millennium, and that this acceleration is directly related to the spike in surface temperature over the past century (i.e. the “hockey stick”).

Benjamin Strauss of Climate Central penned another paper on sea levels with Kopp on Monday writing:

“I think these studies really put the human fingerprint on Miami Beach’s hundred-million-dollar saltwater flooding problem, and really a lot of what’s going on in South Florida,” Strauss said.

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