The transport sector, which includes road traffic, shipping, and aviation, is a significant contributor to global warming and has detrimental effects on air quality. The combustion of fossil fuels results in the emission of gases and particles that alter the chemical composition of the atmosphere. These gases can act as direct greenhouse gases, such as CO2, or undergo complex reactions, forming secondary species. The emitted particles interact with radiation and affect clouds. Emissions from aviation can also lead to the formation of contrails, which affect natural cloud formation processes. While some of these non-CO2 effects contribute to global warming others to cooling.
Due to the significant increase in demand, the contribution of aviation to climate change is expected to grow. Additionally, emissions from road traffic and shipping may also increase depending on changes in mobility and technological advancements. Therefore, it is crucial to develop and implement measures and methods to reduce the anthropogenic climate footprint, including the share of different transport modes. Possible methods to reduce the environmental impact of transport include alternative fuels, such as electricity or hydrogen, and technological advancements, such as after-exhaust treatment systems. Besides these rather technical measures, also operational measures are possible, such as optimized routes.
However, the assessment of the effects of such measures and methods with numerical atmospheric models relies heavily on state-of-the-art emission inventories. It is crucial to provide information on the uncertainties in the emission data to ensure a dependable assessment of air quality and climate effects. This information also contributes to the uncertainties in the representation of physical, chemical, and dynamic processes in atmospheric models.
The objective of this session is to bring together the community involved in the development of transport emissions inventories with the community involved in the use of these inventories. On one hand, the aim is to establish a shared understanding of the different requirements and uncertainties related to emission inventories. On the other hand, particular attention will be given to the latest research on the non-CO2 and air quality effects of transport emissions. Contributions can range from measurement campaigns to modelling results and implementing strategies for reducing the environmental impact of transport.
Nicolas Bellouin