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.
Evidence that global warming is man-made is getting stronger, the head of a UN panel of climate scientists said, in a further blow to sceptics who argue rising temperatures can be explained by natural variations.
Rajendra Pachauri spoke on the sidelines of a conference in Qatar where 200 nations are trying to reach a deal to cut emissions of greenhouse gases to avert floods, droughts, heatwaves and mounting sea levels.
The influential UN climate panel said the probability human activity was the main cause of climate change was "at least 90 per cent" in its last report in 2007.
Pachauri told Reuters late on Wednesday he expected the panel would raise the level of that likelihood even higher in its next report, due in 2013.
The Climate Institute says government and business have much to do to protect Australia's infrastructure from damage in natural disasters.
Science shows that as sea levels and global temperature rise, the frequency of extreme floods, droughts and bushfires will rise exponentially.
Scientists have developed a calculator that can guide coastal planners on the height and positioning necessary for infrastructure to avoid inundation and erosion as sea levels rise.
Called 'Canute – the Sea Level Calculator', it will estimate the necessary elevation for infrastructure on hard shorelines. In the case of soft shorelines the webtool will estimate the distance infrastructure needs to be set back from the water to avoid shoreline recession.