Population Growth Makes It Harder to Address Global Warming

That one should be obvious, but for some reason almost no one ever says it. This is why it is very nice to see Eduardo Porter's piece making the point in the NYT today.

The basic point is probably too simple for economists to understand, but if we have 20 percent fewer people in 2050 than in a baseline scenario, then they all can emit 20 percent more greenhouse gas (GHG) emissions in that year and have the same amount of total emissions. Alternatively, if we have the same amount of per capit...