KUNMING - China's demand for natural gas will continue to soar toward 2040, outstripping domestic output by around 43 percent, according to an International Energy Agency (IEA) report published Tuesday.

"China's annual gas production will more than double to 340 billion cubic meters in 2040, with shale gas a major contributor, but consumption is foreseen to grow even faster, reaching 600 billion cubic meters," said the China Special Report of the World Energy Outlook 2017.

The report, launched in the southwestern Chinese city of Kunming, Yunnan Province, said that by 2040 China would be involved in about one-quarter of the global long-distance natural gas trade.

The rise of natural gas use is the result of the government promoting natural gas as a cleaner alternative to coal. Overall energy demand is growing much slower than that during the early 2000s, the report noted

In the first eight months of this year, China used 150 billion cubic meters of natural gas, 37.9 percent of which was imported, according to the National Development and Reform Commission.

From January to August, gas output rose by 10.8 percent year on year, though consumption grew 17.8 percent, fueled by the coal-to-gas switch campaign that encourages residents to use clean energy for household heating, the commission said.

The IEA report forecast that the share of natural gas in the energy mix would double to 12 percent by 2040. That of coal will drop to 45 percent.

The share of coal in power generation will also decline from about two-thirds in 2016 to less than 40 percent by 2040, according to the report.