China gives UN updated climate pledges

China has submitted updated nationally determined contributions (NDCs) to fight climate change, a UN registry shows, formally boosting headline emission-cutting pledges but offering nothing new ahead of key climate talks in Glasgow.

The submission documents, published on the website of the UN Framework Convention on Climate Change (UNFCCC), showed that China aims to have its carbon dioxide emissions peak before 2030 and to become carbon neutral before 2060, enshrining earlier pledges made by President Xi Jinping.

China, the world's biggest emitter of greenhouse gases, also formalised a commitment to raising the share of non-fossil fuels in its primary energy consumption to 25 per cent by 2030, higher than a previous pledge of 20 per cent and increasing wind and solar power capacity to more than 1200 gigawatts.

NDCs are non-binding national climate change plans that must be submitted regularly to the United Nations as part of the 2015 Paris Agreement, with countries expected to "enhance ambition" if they are able to do so.

Some experts had been hoping for more from China, however, ahead of the UN Climate Change Conference in Glasgow, known as COP26, which begins on Sunday.

A Chinese government official said this week the main priority of Glasgow was to establish a $US100 billion ($A132 billion) a year fund that richer countries will pay into for the developing world to help mitigate climate risks.

Li Shuo, a policy adviser at Greenpeace China, said the lack of new pledges from officials in Beijing "casts a shadow on the global climate effort."

"In light of the domestic economic uncertainties, the country appears hesitant to embrace stronger near term targets, and missed an opportunity to demonstrate ambition," Li said in emailed comments.

China is currently grappling with its worst electricity shortages in years and has asked miners to increase production of coal to supply power plants.

It relies on coal-fired power generation, a major contributor to carbon dioxide emissions, for almost 60 per cent of its electricity.

"Six years after the Paris Agreement, China's choice epitomises the lack of determination to step up climate action among some of the major economies," Li said.