A Fresh View of Sichuan’s Air Pollution Solutions

I recently had my ear to the ground in and around Chengdu, the capital of southwestern China’s Sichuan province. Two things struck me about the air quality in the city. First, the air seemed far cleaner than during my last visit in 2007 despite a near doubling of the city’s population and a many-fold increase in the number of cars on the significantly larger numbers of highways and flyovers. According to the weather app on my phone, air quality during our 10-day visit ranged from “good” to “unhealthy sensitive,” with most days in the “moderate” category. Fall skies were often gray, but not brown, and when there was blue sky, it actually looked blue. A 31-year-old friend, who grew up in nearby Guanghan, told me it was the first time she could remember seeing mountain peaks from her parents’ home.

Second, I was amazed at the very concerted and coordinated efforts taken by the local government and citizens to achieve this result. All of the many taxis and buses in Chengdu run on natural gas. Moped type scooters in the city are all battery operated. The two stroke engines that were so prevalent in 2007 are gone while bicycle sharing volume has exploded. There are a wide variety of electric cars on the road ranging from Chinese-branded subcompacts to familiar-bodied Hondas and Cadillacs. Mercedes Benz has a joint venture with BAIC and have many electric luxury vehicles on the road. Many private and ride share vehicles are electric, and sport a special green license plate that assures them of 1/2 price parking in the city.

During my stay, I spoke extensively with Dr. Tang Ya, Professor of Environmental Biology at the College of Environment, Sichuan University. Professor Tang told me that Sichuan has replaced almost all of its coal-fired electric plants with a combination of hydro, solar, wind, and natural gas. He shared that the province is doing extensive studies on the best species of trees to plant, particularly along highway corridors, that will absorb the maximum amount of chemicals harmful to health and the ozone layer, as well as particulate. Streets and highways are also swept constantly, by hand and by vehicle. This practice reduces the particulate kicked up by traffic and reduces stormwater pollution. (I could write a whole additional post on Sichuan’s efforts related to water pollution.)

Not all of Sichuan’s technical solutions are effective, but they are innovative. I asked Professor Tang about the mist cannons I had seen mounted on trucks roaming neighborhoods in Chengdu. The cannons shoot nebulized water particles up to 60 meters high in an attempt to literally rain specks of particulate dust out of the urban air. Dr. Tang said that even though this method of air pollution control is largely ineffective, cities are loathe to terminate the use of the $100,000 machines they have purchased.

While China is often singled out as a major source of the world’s air pollution, they are also implementing wide-ranging collaborative programs to correct past practices. Between my personal observations and conversation with Professor Tang, it appears to me that we could learn a great deal from efforts in Sichuan to significantly curb emissions here at home, even as the number of vehicles on our roads increase.