NASA: Unavoidable Sea Rise Coming Within About a Century

Based on 23 years of satellite imagery showing variations around the world, NASA researchers say that rising sea levels are "unavoidable" and could increase by several feet within a century, or perhaps longer.

"Given what we know now about how the ocean expands as it warms and how ice sheets and glaciers are adding water to the seas, it's pretty certain we are locked into at least three feet of sea level rise, and probably more," said Steve Nerem of the University of Colorado in Boulder, according to NASA.

"But we don't know whether it will happen within a century or somewhat longer," said Nerem, who leads the space agency's sea level change team.

NASA researchers said sea level change will happen differently in different parts of the world, depending on ocean currents and natural cycles.

"Sea level along the west coast of the United States has actually fallen over the past 20 years because long-term natural cycles there are hiding the impact of global warming," said Josh Willis, an oceanographer at NASA's Jet Propulsion Laboratory.

"However, there are signs this pattern is changing. We can expect accelerated rates of sea level rise along this coast over the next decade as the region recovers from its temporary sea level 'deficit,'" he said.

NASA scientist Tom Wagner told reporters during a conference call on Wednesday that the public needs to be aware of how the potential changes will affect them in the future, said Reuters.

"People need to understand that the planet is not only changing, it's changed," said Wagner. "If you're going to put in major infrastructure like a water treatment plant or a power plant in a coastal zone ... we have data you can now use to estimate what the impacts are going to be in the next 100 years."

Researchers said the biggest challenge for forecasting future sea levels is predicting how much the polar ice sheets will melt over the coming years.

"Significant changes are taking place today on ice sheets," said Eric Rignot, a glaciologist at the University of California in Irvine. "It would take centuries to reverse the trend of ice retreat."

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