My research interests focus on understanding atmospheric chemistry within the context of the earth’s climate system. The composition of the earth’s atmosphere determines its radiative budget. At the same time the abundance of aerosols and greenhouse gases is controlled by atmospheric chemistry and physics. Through an integration of atmospheric chemical models and atmospheric measurements I seek to understand atmospheric chemistry over the historical record and in a future climate. Projections of future climate change are coupled with changes in atmospheric composition whose impacts extend to air quality. An understanding how the chemistry and composition of the atmosphere may change over the 21st Century is essential in preparing adaptive responses or establishing mitigation strategies. These changes not only drive climate change but also directly threaten human health, agricultural productivity, and natural ecosystems. I am actively involved in earth system modeling in collaboration with the Community Earth System Model (http://www2.cesm.ucar.edu/). This model is a state-of-the-art model used for future assessments of climate change.