Seven provinces and cities in China are to set caps on their greenhouse gas emissions, following a directive from central government. It’s the first time the Chinese government has called for any absolute caps on emissions, having so far preferred softer “carbon intensity” targets.

The move is a first step towards establishing carbon trading markets in China and further evidence of the country’s commitment to tackling climate change, says Felix Preston of Chatham House, a foreign-policy think tank based in London.

On 13 January China’s National Development and Reform Commission asked the cities of Beijing, Tianjin, Shanghai, Chongqing and Shenzhen, and the provinces of Hubei and Guangdong, to set “overall emissions control targets”.

The government hinted this move was coming last August, when it released a policy paper arguing that absolute caps were the only way to establish a working carbon market.

The new regional pilot projects are valuable steps towards a national carbon market, Preston says. For them to work, the cities and provinces will need to settle on stringent targets to keep the carbon price high, and collect reliable emissions data to ensure the targets are being met, he adds.

By allowing companies and institutions to trade emissions, carbon markets ensure that greenhouse gas emissions are cut in a cost-effective way. Europe has so far led the way in carbon markets after establishing its Emissions Trading Scheme in 2005. China would be a major new player.

A national Chinese carbon market would be a big step towards a global carbon market, says Preston, especially if the EU and Chinese markets could be linked. » Read more: China set to launch first caps on CO2 emissions

Local or imported? Conventional or organic? Can you make choices that will keep your diet healthy and reduce your carbon footprint? Is it possible to eat green? Does it even matter?

It may surprise you to learn that our diets account for up to twice as many greenhouse emissions as driving. One recent study suggested that the average US household’s annual carbon food-print is 8.1 tonnes of “equivalent CO2 emissions” or CO2eq (a measure that incorporates any other greenhouse gases produced alongside the CO2). That’s almost twice the 4.4 tonnes of CO2eq emitted by driving a 25-mile-per-US gallon (9 litres per 100 kilometres) vehicle 19,000 km – a typical year’s mileage in the US.

As greenhouse gas emissions attract ever greater scrutiny and criticism, the fields of sustainable consumption and life-cycle carbon accounting have prompted academics to tally the greenhouse gas emissions of hundreds of products and manufacturing processes so …