Much has been made of the domestic political roadblocks between US President Barack Obama and climate action. But by using existing treaties he can get around the hostile Congress and help cut global emissions.
US President Barack Obama's new climate plan aims to cut greenhouse emissions from the nation's coal-dominated power sector by 32% by 2030. Will it get through, and how will it affect this year's climate talks?
The term 'carbon tax' is a political poison in Australia, thanks to the previous carbon tax which was actually an emissions trading scheme. Yet ironically, many economists prefer a tax over an ETS anyway.
A year after the demise of the carbon tax, we might expect both coal and greenhouse emissions to have bounced back, at the expense of renewables like hydroelectricity. Sure enough, that's what happened.
To avoid dangerous climate change there is a finite amount of greenhouse gas emissions, in particular CO<sub>2</sub>, that we can add to the atmosphere - our global carbon budget. If we use our budget wisely, we have until about 2050 to transition to zero net emissions. But how do we get there?
China's formal climate target shows that the world's largest greenhouse emitter is determined to green its economy on an unprecedented scale - and that it can bring the rest of the world along for the ride.
Greenhouse emissions from the aviation industry are still largely unregulated. The prospect of regulations for US flights sounds like progress, but it won't happen without an elusive international consensus.
The Grattan Institute has reported that the costs of solar panels have outweighed the benefits by almost A$10 billion in Australia. But the real benefits of cutting greenhouse emissions are much larger.
Nuclear power isn't 'zero-emission', as many proponents claim. Factor in uranium mining, power plant construction, and other factors and it has similar emissions to wind power. But that's still lower than fossil fuels.
Federal environment minister Greg Hunt has hailed the first round of Emissions Reduction Fund auctions as a "stunning result". But extrapolating the numbers puts Australia behind on its carbon targets.
The Climate Change Authority has recommended Australia cut greenhouse gas emissions 30% below 2000 levels by 2025. While sensible, the government is unlikely to accept, and the target misses bigger opportunities to cut emissions.