Bradford Seminar Series: "Connecting Local Climate Impacts to Global Policy Targets"
Assessing the potential impacts of climate change is essential to setting sound targets that minimize the costs and maximize the benefits of both adaptation and mitigation. Conventional wisdom, first codified in the UNFCCC’s 1992 agreement to stabilize greenhouse gas concentrations at levels that would prevent dangerous anthropogenic interference with the climate system, suggests that impacts are expected to scale with the magnitude of human emissions. However, as demonstrated in the National Research Council’s 2011 report on Climate Stabilization Targets and in the recent literature, the relationship between carbon emissions, global temperature, and impacts may be complicated by non-linear responses of the physical system to global forcing as well as by confounding factors such as aerosol emissions and land use change. Here we explore the extent to which projected future changes in a series of impact-relevant metrics, based on the US EPA climate indicators, the USGCRP 2009 report on global climate change impacts in the United States, and the recent literature, and calculated from CMIP3 and CMIP5 simulations, scale with carbon-equivalent greenhouse gas emissions and global mean temperature, and hence might reliably be used to distinguish between the impacts of various climate targets.