Key facts
- Trees in Beijing have been found to contribute to ozone smog.
- This occurs through the emission of biogenic volatile organic compounds (BVOCs).
- BVOCs react with nitrogen oxides (NOx) to produce ozone.
- The phenomenon is more pronounced during hot weather conditions.
Scientists in China have identified trees as a source of ozone smog in Beijing, a finding that could reshape understanding of urban air pollution. Previously, urban ozone pollution was primarily attributed to industrial emissions and vehicle exhaust. However, new research indicates that trees, particularly during hot weather, emit biogenic volatile organic compounds (BVOCs). These compounds then react with nitrogen oxides (NOx), which are largely produced by human activities such as vehicle emissions and industrial processes, to form ground-level ozone.
This discovery suggests that the complex chemistry of urban air pollution involves natural sources in addition to anthropogenic ones. The formation of ozone is a photochemical reaction that is accelerated by sunlight and high temperatures, common conditions in Beijing during summer months. Understanding the role of biogenic emissions is crucial for developing more effective strategies to combat air pollution in urban environments.