According to the latest from NASA, however, the projections the panel made for a rise in global sea levels of 1 to 3 feet may already be outdated.
According to Steven Nerem
of the University of Colorado, we are "locked into at least 3 feet of sea level rise, and probably more."
Nerem said experts now think a rise in sea levels toward "the higher end of that range is more likely, and the question remains how that range might have to shift upwards."
This is startling news if you are one of the 150 million people on Earth who live near the ocean. Even if you don't live close to the sea, you probably use goods that are manufactured in plants near the water or vacation at the beach.
Even NASA is finding some of its critical infrastructure
threatened by the rising seas.
There are three main causes for rising sea levels: The expansion of warmer ocean water, melting mountain glaciers, and ice loss from the massive Greenland and Antarctic ice sheets.
The latter of those causes has scientists at NASA the most concerned and is a key area of focus in the "intensive research effort" the agency announced on Wednesday.
One of those projects, called Oceans Melting Greenland
, which goes by the intentional acronym of OMG (coincidental, right?) will spend the next six years trying to determine how the Greenland Ice Sheet is contributing to sea level rise.
The Jakobshavn Glacier
, the fastest-moving glacier in Greenland, recently broke off a piece of ice large enough to cover the island of Manhattan in ice roughly 1,000 feet thick, according to the European Space Agency
The glacier drains more ice-melt from Greenland into the ocean and contributes more to sea level rise than any other feature in the Northern Hemisphere.
If the entire ice sheet in Greenland melted completely, global sea levels would rise about 20 feet, and although this total loss would probably take many centuries to occur, sea levels would rise "as much as 10 feet in a century or two," according to NASA scientist and ice expert Tom Wagner.
Many climate experts say that temperatures are rising faster
than at any point in our known history and that it is largely because of human activities such as the burning of fossil fuels.
NASA's increased focus on climate change
and rising sea levels is not just about future projections. The agency also is demonstrating the past change in a first-of-its-kind visualization of the entire 23-year satellite record of global sea levels.
The agency is using satellite instruments so accurate, NASA Earth Science Division Director Mike Freilich
said that if they were "mounted on a jetliner flying at 40,000 feet, they could detect the bump caused by a dime lying flat on the ground."
The data gathered reveal that sea levels have risen nearly 3 inches since 1992. If that doesn't sound like much, remember that a good rule of thumb is, for every inch of sea level rise, you see 100 inches of run-up inland on the coast.
But the rise is not uniform. Some places have seen sea levels rise more than 9 inches, while others, like the U.S. West Coast, have actually seen slight decreases in sea level.
But before you sell your summer home on Long Island and move to Southern California, you should know that this decrease in sea level was probably temporary. Experts say it was the result of cooler phase in a natural cycle with an unwieldy name: Pacific decadal oscillation.
That cycle recently switched to a warmer one (giving rise to something called the blob
). According to NASA, the West Coast may now start seeing a faster rise in sea level and more than make up for the deficit it has seen over the past 20 years.