New evidence suggesting sea levels will rise to double expected levels this century and that fewer baby fish will grow successfully to maturity in more acidified oceans underline the urgent need for decisive action on climate change, WWF warned. The Australian Earth Sciences Convention has heard that cores drilled up to two kilometers below the Antarctic ice have outlined an earth with a similar climate to the warmer earth projected in current climate assessments. The new evidence was presented by Professor Tim Naish, director of New Zealand's Antarctic Research Centre, recently named a lead author for the next climate change assessment from the Intergovernmental Panel on Climate Change (IPCC). It supports other recent modelling suggesting an average sea level rise this century of one metre or more � double the upper estimate issued by the IPCC. "Given many climate models predict the planet will warm by the same two to three degrees over the next 50 to 100 years, scientists need to urgently understand how temperature changes will affect the polar ice sheet and the speed of likely change," Professor Naish said. "A couple of degrees of temperature change can lead to quite dramatic changes across the world." The ocean acidification study, conducted by Australia's highly regarded Centre of Excellence for Coral Reef Studies, found that as carbon levels rise and ocean water acidifies, the behaviour of baby fish changes dramatically. The behaviours of concern include being attracted to predators rather than cautious of them and a decreased sense of smell. Early experiments using clown fish � the Nemo of the film � found them unable to find their way home in carbonated water. Overall, the behavioural changes decrease larval fish chances of survival by 50 to 80%.