Replacing lawns with almost anything would help. Less water usage and less fertilizer runnoff would be great. But transporting food to "city folk" is way, way m

Replacing lawns with almost anything would help. Less water usage and less fertilizer runnoff would be great. But transporting food to "city folk" is way, way more efficient than transporting food to suburban or rural folk. And a small garden isn't going to move the needle much there. Densification is necessary to reduce per-capita carbon emissions.