Britain and China outperformed the world's other major economies in their rates of decarbonization last year, according to new data.

The UK cut emissions at a higher rate than all of its peers in the Group of 20, with a decarbonization rate of 7.7 percent in 2016, according to a report by PricewaterhouseCooper.

The decarbonization rate of China -- the world’s largest emitter – was 6.5 percent, making it the second highest in the G20 and well above the global average of 2.6 percent.

The new data precedes the release of PwC’s complete Low Carbon Economy Index 2017, due in late October.

Jonathan Grant, director of PwC's Sustainability and Climate Change division and co-author of the report, said China's emissions fell at double the rate of the G20 average last year.

"It was another great result for China, coming second in our Low Carbon Economy Index this year," Grant said. "This is the result of rapid economic growth while keeping emissions flat - largely by tackling coal consumption."

Grant said despite the result, China still has work to do.

"The carbon intensity of China's economy is higher than most emerging and western countries given its reliance on coal to drive heavy industry which supplies much of the world's manufactured goods," said Grant.

The decline in the UK's carbon intensity was attributed to a decline in coal consumption, improved energy efficiency and moderate economic growth.

"The UK's success comes down to policies creating a pretty positive investment climate for low carbon technology and the strength of our services sectors," Grant said.

The UK is using less coal and investing in more renewable power. Its coal consumption halved in 2016, and coal now represents just 7 percent of its energy consumption, down from 23 percent in 2012.

"However, this transition away from coal is now nearly complete," Grant said. "The UK now needs to tackle other parts of the economy – whether it's increasing renewables or efficiency improvements – in order to maintain its position as a climate leader."

Last year, two thirds of the UK's energy gap was filled by another fossil fuel due to the shiftfrom coal toward natural gas.