While we can squabble over the lack of detail, costings, or the mistaken focus on so-called clean coal, one thing is clear: Opposition Leader Malcolm Turnbull has announced the Coalition's target for emissions reductions 27 per cent by 2020.

In 1990, Australia emitted 552.6million tonnes of carbon dioxide.

Divide 552.6 by 150 and you've got a target more than five times as good as Rudd's measly 5per cent by 2020.

Turnbull is right to point out that Labor's trading scheme is too complex and too weak.

In negotiating with emissions-intensive businesses, Prime Minister Kevin Rudd gave in.

In doing so, he left for dead great Aussie landmarks like Kakadu and the Great Barrier Reef.

The Government's scheme, as it stands, ''locks in'' the total amount of carbon pollution our country will emit, leaving no room for individuals to push Australia past that target if we decide we want to aim higher.

For example, one of the many holes in the scheme means that, if an individual decides to ''do their bit'' and reduce their energy usage, they'll be making no difference to Australia's total level of carbon emissions: they'll just be allowing business to pollute more.

Turnbull has rightly identified the huge benefits we can derive from energy efficiency, particularly in the commercial property sector.

This is an area so far overlooked by the Rudd Government, yet one that can reduce Australia's emissions quickly and cheaply.

A focus on reducing energy use in residential and commercial buildings is a plan that can pay for itself.

In his speech to the normally conservative Young Liberals Convention, Turnbull rightly said his approach would have a ''negative net cost''. That is, it can save us more than it costs us.

This is particularly relevant in the broader context of warnings from experts such as Sir Nicholas Stern that failing to combat climate change will yield an economic effect equal to both World Wars and the Great Depression combined.

Turnbull's comment that an emissions trading scheme is ''only one tool in the toolbox'' is sensible.

It's time to focus on concrete measures like moving from fossil fuels, which cause climate change, to renewable energy, which doesn't.

Evan Thornley's announcement last week of the commercialisation and mass roll-out of electric cars in Australia could wind back up to 30per cent of Australia's emissions.

Combined with Turnbull's focus on commercial property, which as a sector is responsible for more than one-fifth of our nation's emissions, Rudd's fixed 5 per cent reduction looks like the response of a climate coward rather than the climate hero he promised voters he would be.

Turnbull also rightly identifies the huge benefits we can unlock through biosequestration.

If Turnbull is serious, he'll extend his focus on soil to Australia's vast emissions from logging by protecting our precious native forests.

One word of warning here: capturing carbon in soil is difficult to quantify (this is why it isn't recognised under the Kyoto scheme) and much more work needs to be done in this area.

Turnbull's announcement echoed an approach mastered by Rudd while in opposition: announce what the Government is going to do anyway, before it gets a chance to make the announcement itself.

Behind the scenes over summer, Rudd's bureaucrats were busily trying to prepare a plan to drive emissions reductions through energy efficiency: now Turnbull (without access to thousands of public servants) got there first.

So now Rudd is left to pick up the pieces of a climate policy in tatters.

The Greens have slammed it, business have slammed it; and now the Opposition is entering the debate, gearing up to take what's left of Rudd's supporters who voted him in on climate change promises.

Turnbull will have a difficult time bringing his divided Opposition to the table on a target of 27 per cent reductions by 2020. He'll win if he focuses on the economic benefits.

The shadow environment minister, Greg Hunt, has been a long-term advocate for a serious response to climate change and will undoubtedly play a bigger role this year.

Maybe, just maybe, the Coalition will be a serious player in the climate change debate: although they've certainly got a long way to go.

Simon Sheikh is national director of the community advocacy group GetUp.