Changes in the amount of greenhouse gases in the atmosphere change its opacity to solar and/or terrestrial radiation and drive climate change. We are interested in the direct and indirect pathways leading from composition changes to "radiative forcing."
We lead the Radiative Forcing Model Intercomparison Project, a set of climate model experiments aimed at understanding how models translate the same change in concentration into different levels of radiative forcing; identifying sources of error in this translation; and testing hypotheses about how human-induced changes in aerosol amounts have affected the large-scale circulation of the atmosphere.
Extremely accurate calculations made for RFMIP have helped establish the radiative forcing our planet has experienced due to increases in greenhouse gas concentrations since industrialization began, allowing observed changes in temperature over time to be projected into the future with greater confidence.