[LiteKeeper]

Agriculture often replaces natural vegetation. How can there be a significant shift in the balance then?

[Bernard Marx]

Agriculture often replaces natural vegetation. How can there be a significant shift in the balance then?

My question exactly. Of course the replacement of natural or agricultural vegetation with asphalt and concrete might have some long term effect (mainly on the global warmers' temperature gauges), but cities really represent a tiny percentage of the world's total area.