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The "longest assessment" Antarcticaice mass, scientists report a rapid increase in melting – six times the annual loss of Antarctic ice mass between 1979 and 2017.
The study published on Monday by the National Academy of Sciences was a joint work by the University of California, Irvine, NASA's Jet Propulsion Laboratory, and Utrecht University in the Netherlands.
"We're on our way to fast sea level rise the next century or so, ”says leading author Eric Rignot.
The team was able to see that between 1979 and 1990, Antarctica killed an average of 40 billion tonnes of ice each year. Between 2009 and 2017, they lost about 252 billion tonnes per year. The melting speed of ice has also increased by almost three times.
Data were obtained from high resolution aerial photographs NASA Operation IceBridge– Satellite radar interferometry from multiple space agencies and the ongoing series of Landsat satellite images.
Rignot warned, "Depending on how old you are and how fast we warm up the planet, you can see a catastrophically sharp rising sea level (4 meters per year)." An increase of 4 meters (about 12 feet) would be enough to make many coastal cities submerged and immersed in much of South Florida.
Climate Center
At present, the ice melt and the corresponding rise in sea level remain at a manageable level. Over the last 40 years, Antarctica's contribution to raising the world's sea level has been only half an inch. But this pace increases as the climate is faster.
Traditionally, the western side of Antarctica has been the largest source of scientists. However, this study reveals that most of the eastern Antarctica is now becoming a bigger player, and "there is also a big problem."
"This region is probably more sensitive climate change than it has been traditionally accepted, and it is important to know, because it contains more ice than the West Antarctica and the Antarctic Peninsula, ”said Rignot.
Because the fastest melt is associated with the rise of western wind, which makes warmer and more saline groundwater under the edges of floating ice shelves because of the changing climate. Ice shelves act as a protective ocean with the ocean, holding land ice blocked.
In the short term, warmer water simply causes more melting, more icebergs and modest sea levels. But in the long run, the process can destabilize this ice barrier. Just like a cork pulled out of a wine bottle, there is concern that it will lead to the land of ice pouring into the ocean, resulting in a sharp rise in sea levels.
This type of broken sea level rise occurred earlier. The last time was at the end of the last Ice Age, when natural climate change was rapidly developing.
"Fourteen thousand years ago, sea levels rose for more than ten years, four centuries. It surprises most people to find out that 20,000 years ago the sea level was 400 feet lower than today," explains York expert, sea level expert growth and book by High Tide On Main Street.
Now human activity acts as a force of nature, directing what has been a very stable sea level during all modern human civilizations back to the overpressure.
"The problem is that melting ice and rising sea tend to follow an exponential path," England said. "It would change or even change immerse many coastal cities. The impact would also be through bogs and distant river rivers. "
CBS News asked Rignot how fast we could start seeing "destabilization in Antarctica so that troublesome, rapid rise in sea level occurs." He replied, "Probably not in the next 20-30 years, but then the risk will increase very fast."
The actual volume and pace of future sea level growth depends on how warm it becomes, England. "It will be largely determined carbon dioxidethat follows from energy production choices, transportation and more that are still surprised in the debate and disputes. "
While scientists cannot predict precisely when ice sheet collapse may occur, England encourages: "The smart way is to understand that this can happen and to work out to minimize the risk."
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