New science of climate change impacts on agriculture implies higher social cost of carbon

Despite substantial advances in climate change impact research in recent years, the scientific basis for damage functions in economic models used to calculate the social cost of carbon (SCC) is either undocumented, difficult to trace, or based on a small number of dated studies. Here we present new damage functions based on the current scientific literature and introduce these into an integrated assessment model (IAM) in order to estimate a new SCC. We focus on the agricultural sector, use two methods for determining the yield impacts of warming, and the GTAP CGE model to calculate the economic consequences of yield shocks. These new damage functions reveal far more adverse agricultural impacts than currently represented in IAMs. Impacts in the agriculture increase from net benefits of $2.7 ton −1 CO 2 to net costs of $8.5 ton −1 , leading the total SCC to more than double. Climate change impacts in models used to calculate the social cost of carbon (SCC) are either poorly documented or based on a small number of dated studies. Here, the authors estimate new damages for the agricultural sector and find that updating this sector alone causes the SCC to increase substantially.