The optimal social cost of carbon is in general equilibrium proportional to GDP if utility is logarithmic, production is Cobb-Douglas, depreciation in 100% every period, climate damages as fraction of production decline exponentially with the stock of atmospheric carbon, and fossil fuel...

We present a model based on Keynesian aggregate demand and labor productivity growth to study how climate damage affects the long-run evolution of the economy. Climate change induced by greenhouse gas lowers profitability, reducing investment and cutting output in the short and long runs....