Earlier this year, then Prime Minister Kevin Rudd's Labor party shelved its emissions trading scheme until 2013, after meeting heavy opposition in the Senate. Since then Julia Gillard has deposed Rudd as leader of the party and called the election - so what exactly has changed?
Labor's leanings
In a speech last month Gillard said The Carbon Pollution Reduction Scheme (CPRS) – which would make businesses pay to emit carbon – will still be delayed until at least 2012, but will now involve the establishment of an expert commission, and a community assembly.
The Climate Change Commission will be responsible for explaining the science of climate change, while the Citizens' Assembly will be given a year to examine the evidence, and look at possible consequences of introducing emissions trading, with the aim of persuading citizens that some costs are worthwhile.
"We must acknowledge that Australians have real concerns about making changes that are this big and they need more information," Gillard said.
"My government will always act with the interests of those Australians in mind. I have argued before that it is the job of good governments to take on major economic challenges and work through them in a way that makes sure every Australian can participate in creating the solution."
Until then the Labor party are proposing a number of interim measures which will provide opportunities for those in the environmental industries.
A $1bn investment in infrastructure will make it easier to connect renewable energy sources such as wind and solar power to the electricity grid, helping deliver the Government's commitment to 20 per cent of Australia's electricity supply coming from renewable sources by 2020.
The government will also invest $100m, over four years, in a new Renewable Energy Venture Capital Fund.
And all new coal-fired stations will be required to meet tougher emissions standards with some financial assistance provided.
A Gillard Labor Government will also provide $394m towards a scheme that would give consumers money to trade in old cars for newer, more fuel efficient models models – commonly known as "cash for clunkers".
And it will introduce mandatory carbon dioxide emission standards for all new light vehicles, including cars, from 2015, with a four year transmission period to help the industry adapt. Similar standards have already been introduced in the EU and the US.
Businesses that invest in improving the energy efficiency of their existing buildings will also be able to apply for a one-off bonus tax deduction of 50 per cent of the total cost of works.
Coalition's calculations
Tony Abbott's Coalition, on the other hand, opposes any Carbon Pollution Reduction Scheme.
"From day one under a Coalition government, everyone who uses energy – that's pensioners, retirees, farmers, families and young people – could live without the threat of a carbon tax or an emissions trading scheme that would raise prices, damage industries and cost jobs," said Abbott.
Instead the Coalition proposes a $2.5bn Emissions Reduction Fund to support 140 million tonnes of CO2 emissions reduction activity by business and industry.
Through the fund, incentives will be made available for the oldest and most inefficient power stations, to reduce their emissions.
A Coalition Government would also invest $100m each year to build solar powered homes.
And to accelerate the roll-out, and uptake, of renewable energy right across Australia, 125 mid-scale solar projects will be established in schools and communities, and 25 geothermal or tidal power 'micro' projects will be established in suitable towns.
A Coalition Government will support a major study into the potential for algal synthesis and biofuels, and support a study into replacing high voltage overhead cables in cities with underground cables.
Greens' grants
Bob Brown's Greens Party, who many political commentators are now saying could be a kingmaker for either Labor or the Coalition, also opposed the Rudd government's emission trading scheme, though mainly because it was not effective enough in tackling emissions.
"The Greens opposed the Rudd–Turnbull package because it gave polluters that $22bn reward. It also locked in failure," said Bob Brown.
Instead the Greens propose an interim carbon tax at $23 per tonne, rising each year by the Consumer Price Index, plus four per cent.
This would give a strong price signal on carbon, while leaving open the option of converting to a carbon trading scheme, should the Obama administration, or the rest of the world, agree to adopt carbon trading in the years ahead.
The Greens will also establish binding national emission targets for 2012, 2020 and 2050, supported by a detailed strategy to reduce emissions from the energy, transport, industry, waste and land management sectors.
It is part of the Greens' manifesto to establish a national system of energy efficiency targets, significantly increase the stringency of Minimum Energy Performance Standards (MEPS) for products, buildings and infrastructure, and ensure that renewable electricity provides 30 per cent of national demand by 2020 by introducing subsidies.
