A large comet or asteroid has slammed into the Jupiter, creating an impact site the size of Earth, pictures by an Australian amateur astronomer show.

NASA's Jet Propulsion Laboratory confirmed the discovery using its large infrared telescope at the summit of Mauna Kea in Hawaii, said computer programer Anthony Wesley, 44, who discovered the impact zone while stargazing at home.

Towering Mountain Ash forests covering Victoria state's cool highlands hold four times more carbon, or around 1,900 metric tons of carbon per hectare, than tropical forests, scientists at the Australian National University said.

"Australia and other countries have very serious concerns about this proposal," Garrett said in a speech at the Australian National University in the leadup to the meeting in Madeira, Portugal.

Australia's controversial carbon emissions trading laws passed their first parliamentary hurdle on Thursday but the government still faces a near-impossible task to win approval for the scheme in the upper house Senate.

Plans for the world's most comprehensive carbon-trading scheme face defeat or parliamentary delay after Australia's opposition said on Tuesday it will try to postpone a vote on the laws this year.

Australia's government defended its scheme to cut carbon emissions on Friday, amid mining industry warnings that its carbon trading plan would cost 23,000 resource sector jobs as the country battles recession.

Australia's government shook off on Friday coal industry warnings that 10,000 jobs would be lost and 16 coal mines forced to close unless a planned national carbon emissions trading scheme was dramatically overhauled.

Energy-intensive industries could be offered exemptions by Australia's government on its 20 percent renewable energy target as financial tumult saps support for its climate change policies, a report said on Wednesday.

There are positive signs a climate summit in December will forge a broader pact between rich and poorer nations to fight global warming, a top Australian official and an influential Chinese expert said on Wednesday.