Harvard Climate Seminar

by Frank Keutsch (Harvard/SEAS)

Abstract:

Tropospheric ozone and secondary aerosol affect climate and are known to harm human health and ecosystems. The processing rate of gas-phase reactive carbon compounds is directly coupled to formation of ozone and secondary organic aerosol in the troposphere. I will discuss how well novel bottom-up and top-down observations of the reactive carbon budget agree within the context of anthropogenic influence and the ability to predict amounts of ozone and aerosol.

Solar radiation management (SRM), a geoengineering approach to modify Earth’s climate on a global level, has been receiving growing attention. Although most work has focused on introduction of sulfate aerosol into the stratosphere to reduce solar radiation at the surface, a number of other materials have also been considered. To date, the detailed chemical and physical properties of these materials have mostly been treated in a simplified manner. As an example of the role physicochemical detail plays in understanding consequences of SRM, I will discuss the implications of a more detailed treatment of titania (TiO₂), including the role of different titania polymorphs.