The thick smog blanketing parts of northern China is raising some questions in residents’ heads. What’s really causing this? And why does it seem to be getting worst even though China is leading a massively expensive campaign to reverse the country’s record-peaking pollution by turning to clean energy?
Some are saying the so-called green movement is making the skies blacker. It might seem unconventional, but there is some research and science to back it up.
For starters, large-scale, eco-friendly wind turbines could slow air circulation making it harder for smog to dissipate.
Most of the wind turbines are situated in the grasslands of Hebei and Inner Mongolia to the north of Beijing, one of the most developed and most polluted areas. These wind farms also sit across a major stream of cold air from Siberia. A recent study found that near-surface wind speeds in Beijing had declined significantly, from 3.7 metres per second in the 1970s to just 3 metres per second presently.
Xu Dexiang, a researcher with the Chinese Academy of Meteorological Sciences, points to studies conducted in China and abroad which concluded that wind farms could affect the movement of ground air.
Significantly reduced wind speeds had been recorded in areas within 100km from the wind farms, Xu said.
Critics also point to the idea that the thick smog is a byproduct of Beijing’s switching winter heating sources from coal to natural gas.
Natural gas produces water and carbon dioxide when burnt instead of the dust and smoke produced by coal. However, the water vapor can also increase the concentration of air pollutants near ground. Ongoing research has suggested that tiny water molecules in the air may speed up chemical reactions resulting in worse smog.
Wang Zifa, a researcher with the Chinese Academy of Sciences’ Institute of Atmospheric Physics, said burning natural gas in China pumps more than 300 million tonnes of water into the atmosphere each year, or 30 times the amount of water in Hangzhou’s famous West Lake.
But despite these numbers, Wang says water vapor accounts for an “almost negligible” fraction of water in the whole atmosphere.
Perhaps, the solution lies somewhere in between.
Wang says China could counter its smog problem when the whole country works together to reduce the emission of air pollutants.
