Aug. 3 (Bloomberg) -- Climate change threatens World Heritage sites in Australia including the Sydney Opera House and Great Barrier Reef, a report said today as lawmakers prepare to vote on a government plan to cut greenhouse gas emissions.

The sites are at risk from lower rainfall, higher sea and land temperatures, severe storms, increased acidity in the ocean or rising sea levels, according to the Australian National University report released in the capital, Canberra.

Environment Minister Peter Garrett used the study to press the government’s case for an agreement on emissions cuts before an international conference on the issue in December. “The disintegration of our World Heritage areas would be an irreparable loss,” he said in a statement. “We must act now.”

The government is trying to win the votes of seven opposition or minority party lawmakers in the Senate, or upper house of Parliament, to pass its Carbon Pollution Reduction Scheme in a vote scheduled for Aug. 13.

The Sydney Opera House, designed by Danish architect Joern Utzon and inaugurated in 1973, was described by the United Nations’ Educational, Scientific and Cultural Organization as a “great architectural work of the 20th century” that has had an “enduring influence” on architecture.

It is threatened by rising sea levels and flooding due to storms, according to the ANU report. The Great Barrier Reef, spanning 344,000 square kilometers (133,000 square miles) off the northeastern coast, faces further coral bleaching and reduced coral growth, it said. Kakadu National Park in the Northern Territory is also under threat.

Vote Defeat

The government legislation faces likely defeat in the Senate vote because the minority Greens say it is too weak. Opposition lawmakers say it will drive up costs for business while failing to stem climate change because major international polluters don’t have similar plans in place.

The legislation would see carbon trading begin in 2011 to help cut greenhouse gases by between 5 percent and 15 percent of their 2000 level within 10 years. That target may rise to 25 percent in the event of a global agreement on climate change.

China and the U.S., the world’s largest polluters, have yet to commit to targets for cutting greenhouse gases ahead of a December meeting of 200 countries in Copenhagen. Participants disagree on how much financial and technological aid developed nations, which have been polluting longer, should provide to emerging economies.

To contact the reporter on this story: Gemma Daley in Canberra at gdaley@bloomberg.net

Last Updated: August 2, 2009 23:54 EDT