Certainly, the human footprint on the planet has been significant, and we should all be doing what we can to reduce it - I live in NYC where we have the lightest per capita footprint in the US (I raised my family in an apartment and haven't owned a car since 1994).

Birth rates are indeed falling, and likely to continue falling, and will stop the human population from increasing. It's just a question of how fast. But falling birth rates also have important societal impacts that shouldn't be ignored. At the margins, I feel less guilty about my third child than I might have in 1980.