[socratees]

One thing for sure, We aren't filling up earth's surface at that speed. I'm agnostic about the other issues surrounding population growth, but the authors would've made more impact if they used real ratios ( like land surface used per person, a certain natural resource consumed per person, etc.)

[sliverstorm]

People haven't agreed yet what ratios matter, so I think it's acceptable to focus on the concrete numbers at this point- particularly for the layman, which NPR must consider.

'Which ratios' is a very important question- odds are there are only a handful that will really matter. For example, we seem to be running out of oil, heavy metals and helium a lot faster than we are land.