SHANGHAI (Reuters) - China’s carbon dioxide (CO2) emissions fell from 2014 to 2016 and might already have peaked, according to a study published on Monday, with structural economic changes allowing Beijing to meet targets earlier than expected.

China vowed before the Paris climate talks in 2015 to bring CO2 emissions to a peak by “around 2030”, and the country’s top climate official, Xie Zhenhua, has already said it could meet the pledge ahead of time.

But the study, published by Nature Geoscience, said “in retrospect, the commitment may have been fulfilled even as it was being made”, with emissions hitting a record 9.53 gigatonnes in 2013 and declining in the following three years, dropping to 9.2 gigatonnes in 2016.

While emissions rose by an average of 9.3 percent per year from 2000 to 2013, China’s economy underwent a “structural break” in 2014, and is shifting to less carbon-intensive high technology sectors, it said.

“Unless there is a significant amount of change - a large government intervention like the stimulus package of 2008 - then China’s emissions will stabilize and gradually go down,” said Dabo Guan, a professor of climate change economics at the University of East Anglia (UEA), one of the authors of the study.

In May, environment group Greenpeace estimated that China’s CO2 emissions rose 4 percent in the first quarter of 2018 after increasing 2 percent last year, adding that “backsliding” on earlier progress could result in China’s biggest annual rise in emissions since 2011 this year.

“I would have genuinely wanted it to have peaked in 2013, but given the increase in 2017 and first few months in 2018, I am cautious,” said Wai-Shin Chan, head of the climate change department at HSBC, adding that coal consumption remained a major component of China’s energy mix.

But the UEA’s Guan said calculations for 2017 are incomplete and fail to take into account rising coal quality, efficiency improvements or land use changes that could have taken more CO2 out of the system.

An early Chinese peak in CO2 emissions would bolster arguments that the Paris agreement is too lenient on the country, an argument made by U.S. President Donald Trump when he vowed to withdraw from the deal last year.

Guan said it is clear the original target of “around 2030” was conservative, but the ultimate issue was not when China peaked, but at what level.

“Even if we peak in 2019 and 2020, if it reaches 13 gigatonnes it would also be a disaster,” he said.