Estimating Global Warming Costs

A short article in the current issue of Scientific American, Warming Will Cost Rich and Poor Countries Alike, discusses modeling results on the cost of global warming under two scenarios. In one scenario, terms of the Paris Agreement are met and in the other that does not happen. The data was generated by the National Bureau of Economic Research.

NBER projects that about 7% of global GDP will be lost by 2100 if greenhouse gas emission growth continues unchanged. The study included analysis of how warming has affected 174 countries since 1960. That was then projected to estimate future effects. Staying on the current path, estimated US cost is 10.5% of GDP, and Canada's loss is projected to be 13%. But if terms of the Paris Agreement are met now, GDP loss would be less than about 3% for the US and Canada.

The researchers believe the GDP loss estimates are conservative because their model because it does not consider increased climate extreme variations that are expected in the future.

It is reasonable to expect that models of economic cost will be refined as more information about the effects of global warming continues to accumulate.