It seems to me that if every person on the planet is attached to the fact that he planted at least 1 or 2 trees during his life, it would qualitatively be able to change life on the planet.
I myself have planted exactly 251 trees, so I guess at least 100 people can have a pass there.Here is this little to known fact about trees, anyone that is aware of the existence of geological era know as carbon, can ask himself this question. From where and why all this coal that we mine comes from? Those are millions and millions of metric tons of coal we are talking about. As we know, this mineral has formed about 360 millions years ago, from fallen trees and other plants. Turn on your imagination now; what happened that all those plants felt simultaneously, throughout entire planet? What forced them to slip underground and turn in to a "rock"? Answer may surprise you, modern scholars are of opinion that trees (and those where some really massive trunks, 2,3 times bigger than those of today) overgrew the planet's capability of their sustainment! Trees caused natural yet cataclysmic climate change to a point of crash and extinction. Trees are killers dude!
My point is, exaggeration in any direction can lead to bad things, let's not plant in to oblivion because it's trendy, reason is the key.