China - the world's largest emitter of greenhouse gases - has announced details of its climate action plan.
The office of Premier Li Keqiang said that emissions "will peak by around 2030" and China would work hard to achieve the target even earlier.
The statement echoes China's declaration last November following a US-China summit.
China's pledge comes ahead of talks late this year in Paris to seek a new global deal on climate change.
The statement, released following a meeting in Paris between Li and French President Francois Hollande, said China aimed to reduce its carbon dioxide emissions per unit of GDP by 60-65% by 2030, from 2005 levels.
The carbon intensity target builds on a previous plan to cut carbon intensity by 40-45% by 2020.
China also aimed to increase the share of non-fossil fuels in its primary energy consumption to about 20% by 2030, the statement added.
Beijing previously set a goal of getting around 15% of its energy from clean sources by 2020.
Analysis by the BBC's science editor, David Shukman
This is a significant moment in international climate negotiations. For years China argued that it was too poor and underdeveloped to even consider accepting any obligations to curb its greenhouse gases.
Now we're witnessing the world's largest emitter playing by the UN's rules and promising even deeper cuts that those suggested some months back. For diplomats and ministers hoping to see a meaningful deal at the climate summit in Paris at the end of the year, this will be a welcome step.
The size of cuts, and the timescale, will of course be judged by many as too little and too late. But for anyone who endured the collapse of talks at the Copenhagen summit six years ago, China is playing a very different and far more constructive game. Will it actually make any difference to global warming?
Scientists always say it does not matter to the atmosphere where the emissions come from and China's will continue to rise for the next 15 years or so, and on their already gargantuan scale.
And today's announcement does not mean that Chinese use of fossil fuels is coming to an end any time soon. On the same day that China has announced this climate plan it also began construction of a massive pipeline that will bring it a lot of gas from Russia.
All countries involved in UN climate talks must submit national plans for cutting emissions ahead of the key Paris talks.
China joins several other countries, including the EU, US and Mexico, that have already committed their plans for tackling climate change, formally known by the UN as INDCs (intended nationally determined contribution).
With China's announcement, the world's biggest polluters - China, the US and the EU - have now all detailed their climate plans ahead of the global climate conference.
Commenting on the statement, Li Shuo, climate analyst for Greenpeace China, said for success in Paris, all players - including China and the EU - needed to up their game.
"Today's pledge must be seen as only the starting point for much more ambitious actions.
"It does not fully reflect the significant energy transition that is already taking place in China.
"Given the dramatic fall in coal consumption, robust renewable energy uptake, and the urgent need to address air pollution, we believe the country can go well beyond what it has proposed today."
China's new climate plan sends a strong message to other countries to do more on climate ahead of this year's negotiations for a new global climate deal, said WWF.
Samantha Smith, global climate leader at WWF, said China was the first major developing country emitter to set a total emissions peak target.
"In doing so, China has committed to both global climate security and to a transformational energy transition at home," she said.
"We emphasise the importance of the fact that China has made commitments beyond its responsibility as a developing country. But we hope that China will continue to find ways to reduce its emissions, which will in turn drive global markets for renewable energy and energy efficiency."
On Monday, at talks in Brussels with EU leaders, the Chinese Premier said the country was seeking a fair, global system to tackle climate change.
China will work with the international community to seek a "fair, reasonable, win-win" global climate governance system, Li said.