thanks to a new us study, the science of climate change may no longer be abused by nations to shrug off responsibility of reducing greenhouse emissions. Scientists from the Scripps Institution of Oceanography, and the Lawrence Livermore National Laboratory have produced the first clear evidence of human-produced global warming in the world's oceans.

The researchers used a combination of computer models and almost 9 million real-world observations of temperature and salinity changes induced by greenhouse gases during the last 40 years. "We were stunned because the models reproduced the penetration of the warming signal in all the oceans. The statistical significance of these results is far too strong and should wipe out claims that global warming is due to non-human factors,' says Tim Barnett, one of the study's authors. In all of the ocean basins, the warming signal found in the upper 700 metres predicted by the models corresponded to the measurements obtained at sea with accuracy exceeding 95 per cent. The correspondence was especially strong in the upper 500 metres of the water column. It is this high degree of visual agreement and statistical significance that led Barnett to conclude that the warming is the product of human influence. Says Barnett, "The debate is no longer whether there is a global warming signal. The debate is what are we going to do about it.'

According to the researchers, the changes in oceans will produce broad-scale alterations across the atmosphere and land. In the decades immediately ahead, the changes will be felt in regional water supplies, including areas impacted by accelerated glacier melting in the South American Andes and in western China, putting millions of people at risk without adequate summertime water.