Bottum also passes along this nugget in the concluding item in First Things:

The relentless quest for environmental sustainability has finally come to its logical conclusion: People are the problem ? so get rid of them. The best way we stewards of the earth can preserve the planet for our children and grandchildren is not to have those children and grandchildren. According to a report from the London School of Economics titled ?Fewer Emitters, Lower Emissions, Less Cost,? contraception may be the most cost-effective method of reducing future carbon-dioxide emissions and thereby slowing climate change.

For a more sensible take on sustainability, check out Roy Cordato?s work on the subject, including the video clip below.