A tough task to cap emissions by around 2030

Now that China has signed a landmark deal with the United States setting targets for carbon emissions out to 2030, it should plan the trajectory of its low-carbon path for the next 16 years.

When would China's carbon emissions peak? This question had been troubling journalists over the past years. Even after China, along with the US, has bolstered the global fight against climate change, some environmental activists are arguing that the deal is not good enough. They say China's carbon emissions could peak earlier - because its coal consumption may peak in the next six years - and doubt whether the goal is ambitious enough for a genuine campaign to fight climate change.

Yet many would argue that China's goal in the deal is a daunting challenge.