Experts have long feared that the warming planet caused by climate change would elevate sea level, a phenomenon with profound impacts on nations worldwide. Now, evidence provides proof that this concern is not unfounded.
Satellite measurements taken by NASA and its partners revealed that global seas have risen about three inches on average since 1992 with the increase in sea level worse in some locations at over nine inches.
U.S. space agency officials said that NASA will continue to conduct investigations of the global phenomenon with the hope that researchers will gain more knowledge about this through new and upcoming satellite missions.
NASA studied sea levels using satellite altimetry, which measures the time it takes a radar burst to hit the surface of the Earth and return to orbiting spacecraft with the measurement being extremely precise. The ICESat satellite also tracks the height of ice sheets using pulses of laser light.
The model used by NASA also includes data from GRACE, twin satellites that are extremely sensitive to the changes in the mass distribution of our planet. The distance between the duo varies as water and ice move around the Earth.
The data researchers have gathered show that sea levels are rising faster than they did half a century ago and more quickly than anticipated. The melting of the ice sheets is also seen as a big factor that will likely boost the speed of the increase in the future.
Scientists estimate that one third of the increase in sea level is due to the expansion of warmer ocean water; a third is attributed to ice loss from the Antarctic and Greenland ice sheets, and a third are from melting mountain glaciers albeit the polar ice sheets can change the rate and result in more rapid increases in the coming years.
Two years ago, the United Nations Intergovernmental Panel on Climate Change (IPCC) released an assessment that were based on the consensus of international researchers stating that the sea levels worldwide would likely increased from one to three feet by the end of this century.
Since this report, new research suggest that the higher end of this estimate is more likely to happen.
"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 Sea Level Change Team lead Steve Nerem, from the University of Colorado, Boulder. "But we don't know whether it will happen within a century or somewhat longer."
Photo: Liam Quinn | Flickr
