Over the past few years, a strong consensus has emerged among scientists: if we are to avoid dangerous levels of climate change (defined as a rise in average global temperature of 2 degrees above pre-industrial levels), we must restrict the concentration of greenhouse gases in the atmosphere to 450 ppm of CO2-equivalent or lower. According to the IPCC [PDF], this means that developed nations must reduce their emissions by between 25% and 40% from 1990 levels by 2020, and 80% to 95% from 1990 levels by 2050. Which makes the Australian government's decision to set themselves a target of a mere 5% to 15% reduction look like a commitment to failure.
The logic behind the target is simply perverse. The Australian government claims to want an international agreement aiming for 450ppm, but thinks this is unachievable. Therefore they have set their target on the basis of an agreement aiming for 550ppm. But by doing this, they are creating a self-fulfilling prophecy to frustrate their own claimed desires. Other nations will use Australia's soft target as an excuse to set similarly soft targets for themselves, with the result that 450ppm really will be unachievable. And that means the Great Barrier Reef will die, Kakadu will turn into a desert, and the Murray and Darling rivers will dry up, with a consequent effect on Australia's agriculture. The Australian government claims not to want this - but by their actions, they are heading there with all speed.
The lesson is simple. To misquote Napoleon, if you want 450ppm, aim for 450ppm. If the rest of the world won't follow, you can always slack off later. But by cutting early and deep, you maximise your flexibility while also demonstrating commitment, making your goal that much more likely.
But contrary to the Australian government's rhetoric, 450ppm was never their goal. Instead, its about ensuring their dirty coal industry stays in business - and so Australia gets lax targets and fat subsidies for polluters. As for the environment - and the reef, and the rivers, and Australia's drinking water - it can go to hell for all they care.
