Using satellite data, scientists reveal 'definitive' study that claims sea levels are rising.
The melting of polar ice caps raised sea levels by nearly 11 millimetres in the past two decades, scientists say, calling it the most definitive measure yet of the impact of climate change.
There have been more than 30 previous estimates of whether and how much the ice caps are shrinking. But the numbers were often vague, with wide ranges, and different studies sometimes contradicted each other, the researchers said.
The new study, released November 30, in the US journal Science, combines data from 10 different satellites since 1992, carefully matching up time periods and geographical locations to make a more accurate and wider-ranging assessment.
''Changes in the mass of ice stored within the polar ice sheets are important because they're a measure of changes in global climate and they directly affect global sea levels,'' says lead researcher Andrew Shepherd from the University of Leeds, in England.