Change in the air

China carbon vow shows change in political climate

China's new pledge to curb carbon emissions is credible and decisive. The proposal, which is intended to form one of the pillars of an international agreement on climate change in Paris this autumn, is an encouraging sign that the country is ready and able to accept global responsibilities, at least in some cases.

Despite Beijing's far from spotless track record in environmental management, last month's promise looks serious, detailed and substantial. Beijing reaffirmed an ambition to reach peak carbon emissions and boost the share of energy coming from non-fossil fuels to 20 per cent by 2030, and added new commitments, like slashing the amount of carbon emitted per unit of GDP by almost two thirds. There's also a plea for the United Nations to make the targets legally binding.

The scheme may even be conservative. The International Energy Agency claims the People's Republic could feasibly meet its target almost a decade earlier, if it were to demand more serious improvements to industrial efficiency. Premier Li Keqiang suggested that CO2 cuts could possibly come sooner than 2030.

But ultimately the pace of change is set by domestic developments rather than obligation to the international community, or the UN's October deadline.

For the first time a potent combination of economic slowdown, widespread anger at environmental damage, plus greener and cheaper technology have made radical change both affordable and desirable. Clean tech will become cheaper still over time, and the restructured economy should favour cleaner services over dirty factories. Falling emissions are a side-effect, not the end game.

But this line of reasoning works the other way too. Reform can be put on hold if circumstances change and the government finds itself in a tight spot. A 2013 pledge to let markets play a "decisive" role in the economy looks far less convincing after Beijing's heavy-handed interventions to stem a stock-market slump.

That's an important caveat. For the budding superpower to willingly sign up to these kinds of commitments is huge progress. Just don't expect genuine concessions on currency, trade or any other hot potatoes until it fits with the agenda at home.