Green groups have urged the federal government to act to halt climate change following the release of findings in a UN report.
Most global warming since the mid-20th century had "very likely" been caused by human activity, a UN Intergovernmental Panel on Climate Change (IPCC) report released in Paris said.
The IPCC report is bad news for Australia as temperatures and sea levels are predicted to rise, unleashing increasingly intense storms, heat waves and heavy rains in the 21st century, the report says.
Australia's coastal communities face disaster, with the report predicting sea levels will rise up to 59 cm, Greens spokeswoman Christine Milne says.
Senator Milne said Australia faced severe weather and the potential for international conflict would increase with rising sea levels.
"The IPCC report is very bad news for Australia and for the whole world in terms of temperature rise," she said.
"It's a disaster for coastal communities because of projected sea level rise of anywhere between 0.18 and 0.59 metres."
She said the IPCC report was very conservative. "Our own scientists have come out ... saying the IPCC is likely to underestimate its sea level rise because it hasn't taken into account the latest science on the glacial melt, particularly in the Antarctic."
The Australian Conservation Foundation (ACF), the Climate Institute and the CSIRO joined Senator Milne in saying the IPCC report had ended the debate on whether global warming was happening.
Unless the Australian federal government legislated to reduce greenhouse pollution and ratified the Kyoto Protocol, future generations would be placed at risk, ACF executive director Don Henry said.
Failing to act on the findings of the report would be akin to committing a crime against future Australians, Mr Henry said.
"If we don't cut greenhouse pollution now and get on board the global fight against climate change we will be knowingly committing a crime against our kids," he said. "It's just like once you know asbestos causes cancer, you've got to do something about it; there's no excuses."
The groups agreed Australia faces severe weather, including cyclones moving further south, and the likelihood of drought across southern Australia.
Climate Institute adviser Erwin Jackson said global warming was mostly being caused by burning coal, oil and gas and he urged the federal government to introduce strong climate change laws, ratify the Kyoto Protocol and legislate price signals to reward business for investment in clean energy technologies.
"The government has to roll up its sleeves and commit to implement a clean energy plan that will ensure all Australia's new electricity generation comes from clean energy sources," he said.
CSIRO Marine and Atmospheric Research scientist, Dr Penny Whetton, was the lead author of the regional climate projections chapter of the IPCC report and said it showed the global warming debate was over.
"It is very likely that most of the rise in global average temperatures since the mid-20th century has been caused by increased greenhouse gas concentrations in the atmosphere," she said.
There was a greater than 90 per cent chance that temperatures were rising due to human activities, she said.
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