Globally, eight out of ten people live in environments where the amount of air pollution, in the form of small airborne particles, is above the guidelines set by the World Health Organization WHO. According to the WHO, atmospheric pollution causes 3.7 million deaths each year. In Skåne, the average life expectancy is seven to ten months shorter, due to air pollution.
Airborne particles, or aerosols, also affect the climate. This is partly because they interact with the incoming sunlight and partly because they are a vital part in the cloud formation process. Aerosols can consist of hundreds of thousands of chemical substances. How aerosols affect the climate can vary; some aerosols have a cooling effect on the climate while others have a heating effect. Unlike greenhouse gases, such as carbon dioxide, aerosols generally have a cooling effect on the climate. This means they can reduce global warming.
In her thesis, Emilie Öström has studied how gases in the atmosphere can create particles and grow them bigger, and what happens to these particles in the atmosphere. The aim of her research is to increase knowledge of these specific aerosol processes, in order to develop and improve climate models that provide us with projections of how greenhouse gas and aerosol emissions interact and affect the future climate.
– Despite its dampening effect on global warming, air pollution is still a major health problem and far from desirable. Since emissions of air pollutants and greenhouse gases affect both the climate and our health, and often have the same sources, we can gain a lot with a common strategy to reduce these emissions, says Emilie Öström, PhD student in Environmental Science at the Center for Environmental and Climate Research and the Institution of Nuclear Physics at the Faculty of Science.
Emilie Öström defends her thesis "Modeling of new particle formation and growth in the atmospheric boundary layer" on Friday 27 October at 9.00 in Rydbergsalen at Fysikum.