What is the most we should take from a poor person to make somebody who is already four times as rich two-thirds of a percent richer yet? Most of us would probably argue for zero. If it does not seem fair to take anything from a poorer person to add less than one percent to the income of a much richer person, then you may need to rethink climate policy.
William Nordhaus, who is the only climate economist to win a Nobel prize, lays out the tradeoffs in the introduction to the model he created to analyze the impacts of CO2 emissions, climate change, and climate policy. If we do nothing to address CO2 emissions, he projects that (after adjusting for inflation and climate damage) annual world per capita consumption will rise from $8,768 in 2020 to $36,819 in 2100 and to $95,981 in the year 2200. Though I am sure even Nordhaus would not defend the precision of these estimates to five significant figures, other projections show income increasing by similar magnitudes. For instance, though they only go to 2060, the OECD projects world inflation-adjusted GDP in 2060 will be more than two and one-half times that of 2020 GDP.
