China's efforts to improve urban air quality are often viewed as a helper for fighting climate change, but a new joint China-U.S. study says otherwise.

The study—carried out by researchers at the Massachusetts Institute of Technology and Tsinghua University in Beijing—was released last week. It shows that China's strategies for cleaning up air do not necessarily lead to carbon dioxide emissions reductions. Sometimes, according to the study, the efforts could actually increase emissions.

The study came as cleaning up air climbed to near the top of China's policy priorities, especially with record air pollution levels in 2013. The smog triggered unprecedented public outcry that motivated Chinese leaders to declare a "war on pollution."

China rolled out its Air Pollution Action Plan, which calls for limiting coal to 65 percent of the primary energy mix and prohibiting any increase in coal use in three major urban regions along the coast. In addition to displacing coal, the plan also promotes the installation of desulfurization, dust-removal equipment and other pollutant treatment technologies in industrial boilers, furnaces and power plants, particularly those close to cities.

"The urgency with which Beijing is tackling air pollution is certainly positive, and these efforts will also have related benefits in curtailing carbon dioxide emissions—to a certain extent," the report said. "But it would be a mistake to view the current initiatives on air pollution, which are primarily aimed at scrubbing coal-related pollutants or reducing coal use, as perfectly aligned with carbon reduction."

That is because once low-cost opportunities to reduce coal are exhausted, the continued displacement of coal from China's energy mix will become more expensive. If the focus remains narrowly on air quality, the researchers say, Chinese power producers will likely stick with end-of-pipe solutions—such as scrubbing pollutants from the exhaust stream of coal power plants—rather than switching to use more renewable energy.

That, in turn, slows down China's green transition in energy structure. Worse yet, according to the researchers, if the pollution-scrubbing technologies are running on coal-generated electricity, the use of them could increase carbon emissions, even as air quality improves.

Would a carbon price be better than scrubbing?

Wang Tao, an expert on climate and energy policy at the Carnegie-Tsinghua Center for Global Policy in Beijing, agreed.

"Although fighting air pollution and combating climate change can go hand in hand in many aspects, sometimes they also conflict with each other," Wang said. He added that Chinese policymakers will have to decide their short- and long-term goals, based on which environmental problems are most pressing.

For the report authors, an easier approach is to put a price on carbon dioxide emissions, which could ensure air pollution control does not come at the expense of sound, long-term climate change management.

"If China's leaders are willing to take aggressive steps to address climate change specifically by pricing CO2 emissions, they would make meaningful process on air quality too," the researchers said in the report.

"Such a prioritization can also help the government avoid part of an otherwise substantial investment in technology to scrub pollutants and emissions from coal-fired power that will, over time, end up locking in a high-carbon energy system."

China already kicked off seven regionwide carbon trading pilot programs, trading 15.68 million tons of carbon dioxide at nearly 570 million yuan ($91 million) by the end of 2014. Some government officials have indicated that an introduction of a carbon tax and a nationwide carbon market is also in the pipeline.

Click here to read the report.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500