The developed world has advanced mightily over 60 years, increasing its lifespan and per capita income. But such growth has been a double-edged sword: using cheap fossil fuels has enabled the good fortune, but it has also created an environmental hazard that could lead to irreversible damage. Now is the time to address this inequity. Indeed, there’s been a cost to fossil fuel development that oil, gas, and coal companies have not borne. In other words, CO2 and other greenhouse gases have not generally been taxed — a cost that the greater society has picked up. Enter carbon credits, which...