 Per head, Australians are among the world's worst polluters |
The Walk Against Warming rallies were held in state capital cities and about 50 towns as the country prepares for a general election on 24 November.
Organisers said up to 150,000 people had taken part. The biggest protests were in Melbourne and Sydney.
Campaigners want greenhouse gas emissions to be cut by 30% by 2020.
Police estimated that up to 30,000 activists gathered in Melbourne, while in Sydney, organisers said more than 28,000 people turned up.
'Credibility problems'
There were reportedly other rallies in the New South Wales marginal seats of Parramatta, Dobell and Eden-Monaro, along with most other states and territories.
Alex Marr, a director of one of the groups behind the rallies, The Wilderness Society, told the Sydney protest: "Both major parties have credibility problems on climate change."
The Labor opposition has pledged to cut greenhouse gas emissions by 60% by 2050 and ratify the 1997 Kyoto Protocol on cutting greenhouse gas emissions.
Liberal Party PM John Howard says any global agreement must include big developing nations such as China and India.
Australia and the US are the only major industrialised nations not to have ratified the Kyoto Protocol.
Australia, which has recently seen record drought conditions, is one of the worst polluters in the world on a per capita basis.
