The objective of this effort is to improve the way that technology and uncertainty are represented and treated in integrated assessment models (IAMs) of the coupled human-climate system. The research project will address key gaps in representing technological change and the treatment of risk and uncertainty within IAMs. Integrated Assessment Models contribute to our understanding of many issues in climate change, such as the development of internally consistent global emission scenarios and the exploration of economic, technological, emissions, and climate impacts of alternative mitigation strategies. Specific elements of this work will also contribute to improving the spatial and temporal resolution of IAMs for understanding climate impacts. The research will advance methods in three critical areas: 1) modeling of climate mitigation as sequential decisions under uncertainty, 2) modeling of uncertainty in technological change that represents structural uncertainty and 3) design of reduced-form models of complex earth systems processes to improve the ability to analyze the risks of climate change.