Emission cuts needed: PM

Sea levels are rising more quickly off the WA coast than anywhere else in Australia, according to a new climate change report that warns that without sizeable cuts to emissions within the next decade the planet will suffer irreversible damage.

The Climate Commission's report, A Critical Decade, says evidence of human-induced climate change is "overwhelming and clear" and that to keep temperature rises to 2C or less above pre-industrial levels, carbon emissions must peak by 2015 and reach zero by 2050.

It estimated that the world needs to limit carbon dioxide emissions to one trillion tonnes between 2000 and 2050 to meet this challenge.

However, in the first nine years of this period, 30 per cent of the "carbon budget" had already been consumed.

The commission was set up by Prime Minister Julia Gillard to inform the public about the science and impact of climate change in response to falling support for taking action on curbing carbon emissions and growing scepticism that global warming was real.

Ms Gillard used the report yesterday to build support for her carbon tax, despite not having finalised key details such as the starting price and household compensation.

She said the science made it clear once again that human-induced climate change was real and scientists should be trusted.

"We don't have time for false claims in this debate," she said.

But the Greens have also used the report's dire warnings to push for much deeper and quicker cuts to emissions. They also suggested liquefied natural gas has only a short window for its use as a cleaner fossil fuel before it is replaced by renewable energy sources.

Opposition Leader Tony Abbott claimed the report bolstered his case for the coalition's direct action policy of reducing emissions by sequestering carbon in soil and trees, which would meet the bipartisan goal of a 5 per cent cut by 2020.

"It's more than enough to get our emissions down by 5 per cent by 2020 and that's our objective," Mr Abbott said.

The report, prepared by climate scientist Will Steffen, compiles the latest scientific evidence on climate change from a raft of expert sources, including the CSIRO, the Weather Bureau and the United Nation's climate change panel.

He said without strong action on reducing emissions now, there was a big risk that climate change would undermine society's prosperity, health, stability and way of life.

Even a five-year delay on the peak for emissions would require much deeper and faster cuts to meet the target, which Professor Steffen said would be impossible on anything but a "wartime footing".

While the report did endorse the idea of sequestering carbon in the soil - the centrepiece of Mr Abbott's direct action policy - chief commissioner Tim Flannery said it offered only short-term gain and a price on carbon was unavoidable to drive investment in cleaner renewable energy sources.

Professor Steffen's report said sea levels had risen globally by 20cm since the late 1800s and were projected to increase by another 20cm by 2050.

But this overall average hid wild variations between regions, with a 2008 study by the Weather Bureau's National Tidal Centre indicating sea levels off Perth had increased 8.1mm a year since the early 1990s.

A 0.5m sea level rise would see storm surges cause extreme one-in-100-year coastal flooding every year in Perth, with low-lying suburbs on the Swan and Canning rivers most vulnerable.

The decline in average annual rainfall in the South West since the 1970s was one of the clearest examples of climate change's impact on Australia and was expected to continue, the report noted.

Despite the report's findings, WA Liberal Dennis Jensen said temperatures had stabilised while Liberal powerbroker Nick Minchin said it was wrong for the commission to declare the scientific debate over.