It won't do much, I suspect, because the reasoning will be "yeah, climate change is real and is a significant danger...but look at how small Australia's contrib

It won't do much, I suspect, because the reasoning will be "yeah, climate change is real and is a significant danger...but look at how small Australia's contribution is compared to China". Which is effectively where it is at in Canada -- every discussion circles back to relative contribution, which is a classic tragedy of the commons (in this case being the air). If we had rational worldwide leadership we could conceivably work greenhouse gases into the WTO and other trade agreements. If China needs to be tamed for everyone else to take part, factor it in.