Developing better methods of monitoring greenhouse gas emissions is the goal of the TRACE Industrial Chair, a four-year research programme launched in January 2018.
Selected by the French National Research Agency (ANR), the Chair is backed by the University of Versailles Saint-Quentin-en-Yvelines and co-funded by SUEZ, Thales Alenia Space and Total. Interview with Philippe Ciais, Chair Coordinator at the Climate and Environment Science Laboratory (LSCE, CEA/CNRS/UVSQ) and a member of the IPCC for the previous reports on climate change.
You have been working on the carbon cycle and greenhouse gases (GHG) for many years. Can you explain the interactions between air pollution and climate warming?
The main thing that air pollution and climate change have in common is their anthropic origin. The use of fossil fuels in transport and industry produces pollutants that degrade air quality and GHGs that affect the climate. The main GHGs whose increased concentration leads to climate change are carbon dioxide (CO2) (combustion of fossil fuels and deforestation), methane (CH4) (activities associated with agriculture, the decomposition of organic waste and the oil and gas sectors) and nitrous oxide (N2O) (nitrogen fertilisers used in agriculture and industry).
The important thing to remember is that the interactions between air quality and climate change are very complex. For example, climate change affects air quality by influencing meteorology. This is the case with heatwaves, which lead to the formation of ozone pollution (O3), favoured by sunshine and high temperatures. These interactions between climate and air quality depend on the nature of the pollutants in the air. On one hand, emissions of black carbon particles warm the climate by absorbing infrared radiation. On the other, nitrogen oxide and sulphur oxide tend to cool the climate, because the aerosols formed from these compounds block solar radiation. In addition, volatile organic compounds (VOCs) are pollutants with an indirect effect on the climate, as they contribute to the formation of ozone pollution, a GHG that warms the climate.