Why Are Greens On The Left?

Why-are-greens-on-the-left?

Around the world green politics is more closely aligned with the left than the right.  It has been said that greens are like tomatoes.  They start green but they always end up red.  Why is this?  There doesn’t seem to be any particularly strong reason why people who believe in the free market shouldn’t also believe in protecting the environment.  Even fascists can like trees.  So why are greens not only pretty consistently liberal, but are also generally liberal even by liberal standards?