China Wants to Cut Down on Coal—And That's Bad for Global WarmingChristina Larson
The current plan to address one of China’s pressing environmental crises—polluted urban air—could have the unintended effect of creating other ecological catastrophes in China and beyond.
Northern China’s reliance on burning coal for heat and energy contributes to the heavy haze that shrouds city buildings, especially in winter, and shortens the life spans of northerners as compared with their southern counterparts by as much as five years, according to a recent study (PDF) in the Proceedings of the National Academy of Sciences.
Beijing and other Chinese cities won’t see frequent blue skies until coal burning is dramatically curtailed in adjacent industrial regions. In September, China’s State Council released a significant new environmental target: trimming coal’s contribution to overall energy output from 67 percent in 2012 to 65 percent in 2017, even as the country’s economy and energy demand continue to grow.
Unfortunately, one scheme to limit coal burning by converting China’s plentiful coal supplies into synthetic natural gas (SNG) presents a host of other ecological worries. To date, China’s government has approved construction of nine large SNG plants in northern and western China, which are projected to generate 37 billion cubic meters of gas each year when completed. At least 30 more proposed plants are awaiting approval.
None of these planned plants are located near large Chinese cities, so the emissions generated in producing the gas will not hang directly over metropolises. But that doesn’t mean the coal-to-gas conversion process is clean. According to a new study (PDF) in Nature Climate Change, the entire life cycle of harvesting coal and turning it into gas produces from 36 percent to 82 percent more total greenhouse gas emissions than burning coal directly—depending on whether the gas is used to generate electricity or power vehicles.
While the most-polluting stages of energy generation could be moved farther from China’s population centers—perhaps allowing for more brighter, cleaner days in Beijing—the net effect could be to accelerate global climate change, argue the study’s authors, Chi-Jen Yang and Robert Jackson of the Nicholas School of the Environment at Duke University.
Moreover, the scarcely populated hinterland regions earmarked for the SNG plants are dry, while converting coal to gas is a water-intensive process. “The water consumption for [synthetic natural gas] production could worsen water shortages in areas already under significant water stress,” write Yang and Jackson. “Overall, the large-scale deployment of SNG will dramatically increase water use, [greenhouse gas] emissions, and additional air and water pollution.”
When it comes to tackling China’s many environmental challenges, it’s, alas, much easier to point out flaws in current government approaches than to find sustainable solutions.