Lives or climate change? The dilemma for China in tapping coal for natural gas
Deaths could be prevented but the price would likely be more greenhouse gas emissions, study finds
China’s push to convert coal into synthetic natural gas could prevent tens of thousands of premature deaths a year, but possibly at the cost of emitting more greenhouse gases, a study has found.
The finding by researchers in China and the United States highlights the dilemma for the world’s second-largest economy as it struggles to balance public health and economic growth with its climate change commitments.
Facing severe air pollution and growing dependence on natural gas imports, Beijing plans to ramp up production of synthetic natural gas (SNG) from coal.
Natural gas produces far fewer of the tiny harmful pollutants emitted by coal-fired plants and small household coal burners used for heating and cooking.
In a paper published in the Proceedings of the National Academy of Sciences, researchers at Princeton and Peking universities estimated that if SNG replace coal in homes, 20,000 to 41,000 premature, air pollution-related deaths would be avoided each year.
Study co-author Denise Mauzerall, a professor of environmental engineering and international affairs at Princeton University, said use of coal-produced synthetic gas could help improve air quality in China but doing so would increase carbon emissions, “which would affect the world”.
Mauzerall said China’s coal-to-gas plants could together emit as much as 143 million tonnes of extra carbon dioxide by 2020.
In a separate report, environmental group Greenpeace said the industry’s carbon emissions could be even higher.
If China’s coal-conversion industry met the targets set in its five-year plan, it would pump out 409 million tonnes of carbon dioxide in 2020, Greenpeace projected. That total is equivalent to four times its 2015 carbon dioxide output and 4 per cent of the country’s total carbon emissions last year.
Greenpeace’s projections included emissions from coal-to-gas plants as well as other plants that would turn coal into oil and various chemicals.
“The process of producing cleaner energy with coal is not clean at all. China should turn to solar or wind power for cleaner energy,” Greenpeace climate and energy campaigner Gan Yiwei said.
Ranping Song, a climate specialist with the World Resources Institute, said converting coal into gas and then using that gas to generate electricity could produce almost twice as much carbon dioxide and other greenhouse gases as simply burning coal directly for power. Synthetic natural gas produced carbon dioxide first during the processing stage and again when the fuel was burned, Song said.
Under its commitments to the Paris Agreement on climate change, China, the world’s largest emitter of carbon dioxide, needs to cut carbon emissions by 60-65 per cent per unit of gross domestic product by 2030, compared with 2005 levels.
It must also boost its use of non-fossil fuels to 20 per cent of its energy use.
Song said that even if China deployed more coal-to-gas plants, it would still be able to meet its goal of stabilising its carbon emissions at about 9.1 billion tonnes annually by 2030 – but the target would be more difficult.
Additional reporting by Associated Press