Average temperatures in Sydney will rise by about 9 degrees during the next 65 years, with devastating consequences including 1,300 more heat-related deaths per year, according to a government study released Wednesday.
With Australia gripped by its worst drought on record, the issue of climate change has emerged as a battleground in this year's national elections.
Prime Minister John Howard has come under renewed criticism for not ratifying the 1997 Kyoto Protocol, making Australia the only major industrial nation other than the U.S. to reject the treaty that mandates lower emissions of global-warming greenhouse gases.
Howard did not comment on the study, which was commissioned by New South Wales, the state that includes Sydney, Australia's largest city.
But New South Wales Premier Morris Iemma called the report "frightening reading" and said the federal government "can no longer put its head in the sand on this issue."
Iemma is a member of the Labor Party, which is hoping to oust Howard's conservative coalition in elections later this year.
The Commonwealth Scientific and Industrial Research Organization, Australia's main scientific group, said average annual temperatures in Sydney will rise from the current 78.8 to around 88 by 2070.
If current climate trends continue, summer temperatures in Sydney's landlocked suburbs — which often top 95 degrees — could rise by as much as 13 degrees, the CSIRO said.
It predicted heat-related deaths of people over 65 will increase to 1,312 by 2050 from the current average of 176 per year. By 2070 Sydney could be in drought for nine out of every 10 years instead of the current average of three, the report said.
"Such trends would also increase evaporation, heat waves, extreme winds and fire risk," the report said.
The CSIRO said hotter temperatures would have significant effects on the ecosystem around Sydney, threatening some already endangered plant species and the animals that feed on them. Rising sea levels could also destroy the natural habitats of many species.
As a major exporter and consumer of carbon dioxide-emitting fossil fuels, Australia rates as one of the world's worst greenhouse gas producers per capita.
Howard says the Kyoto Protocol's steep cuts in carbon dioxide emissions would hurt Australia's economy by handing a competitive advantage to China and India, which are not bound by the treaty.
Australian power companies issued a report Wednesday that said expanding the use of nuclear power and retrofitting coal-fired power stations to capture carbon dioxide is the best way to slow greenhouse emissions. Howard said he agreed with that recommendation.
"The answer is a greater emphasis on clean coal and nuclear power," Howard told reporters. "It's just simply not feasible to run power stations in this country on solar and wind energy."