Because the natural ones are going to burn.
|Click photo to enlarge|
I just read this article while waiting for a plane and it made sober reading.
It looks like we're about to enter a vicious circle that goes something like this:
a) the climate warms
b) forests suffer more bush fires (drier conditions, more lightning)
c) the carbon locked up in forests is released into the atmosphere
d) the climate warms even more
As the article says, we can quickly find ourselves in a "dangerous feedback loop".
I don't know if our "artificial" urban forests can combat such large scale mayhem but we've got nothing to lose by trying that's for sure. If nothing else it might at least mitigate the severity of the thing.
Anyone for Mars?