[yongjik]

According to some researches[1], city residents already generate less CO2 per capita, because they live in a densely packed area and can use resources efficiently (e.g., subways). It makes much more sense to keep people closer to each other and keep farms farther away. (After all, cabbages only have to be transported once in its lifetime. Human beings move in and out every single day.)

[1] http://news.berkeley.edu/2014/01/06/suburban-sprawl-cancels-...

[justinator]

This is true, but it's offset by the suburban sprawl around them. Not everyone who works in the city, lives in the city, so there's longer commutes, etc.

http://news.berkeley.edu/2014/01/06/suburban-sprawl-cancels-...