PNNL

Abstract

This paper examines the role of climate forcing agents other than carbon dioxide using the MiniCAM integrated assessment model. Non-CO2 greenhouse gases are particularly important through the middle of the 21st century. The addition of non-CO2 greenhouse gases abatement options significantly reduces mitigation costs in the first half of the century as compared to a case where only CO2 abatement options are pursued. Non-CO2 greenhouse gas forcing is dominated by methane and tropospheric ozone. Assumptions about the prevalence of methane recovery and local air pollution controls are a critical determinant of reference forcing from these two gases. While the influence of aerosols are small by the end of the century, there is a significant interaction between a climate policy and aerosol cooling near mid-century such that global-mean climate change to 2050 is practically unaffected by mitigation policy.