The authors assess the economic effects in Egypt, under various conditions, of restricting carbon dioxide emissions. They use their model to assess the sensitivity of these effects to alternative specifications: changes in the level or timing of restrictions, changes in the rate of discount of future welfare, and the presence or absence of alternative technologies for generating power. They also analyze a constraint on accumulated emissions of carbon dioxide. Their time model has a time horizon of 100 years, with detailed accounting for every five years, so they can be specific about differences between short- and long-run effects and their implications. However, the results reported here cover only a 60-year period - and are intended only to compare the results of generic,"what if?"questions, not as forecasts. In that 60-year period, the model economy substantially depletes its hydrocarbon reserves, which are the only non produced resource. The authors find that welfare losses due to the imposition of annual restrictions on the rate of carbon dioxide emissions are substantial - ranging from 4.5 percent for a 20 percent reduction in annual carbon dioxide emissions to 22 percent for a 40 percent reduction. The effects of the annual emissions restrictions are relatively nonlinear. The timing of the restrictions is significant. Postponing them provides a longer period for adjustment and makes it possible to continue delivering consumption goods in a relatively unconstrained manner. The form of emissions restrictions is also important. Welfare losses are much higher when constraints are imposed on annual emissions rates rather than on total additions to the accumulation of greenhouse gases. Conventional backstop technologies for maintaining output and consumption - cogeneration, nuclear power, and gas-powered transport - are more significant than unconventional"renewable"technologies,which cannot compete for cost.