"Ecology song" by Stephen Stills, album: Stephen Stills 2, 1970

Fortunes of time making up a rhyme
How do we save tomorrow
Given a voice can you make a choice
Is it black, is it grey, is it yellow
Mother nature made it green
Prettiest place you've ever seen
People don't know what they need

Open your window
What do you see
Do you remember
how it used to be

All of this crying, while the earth is dying
It's a shock they won't stop because of the money
America is lost, figurin' the cost
You can hang your head in shame
It's disgusting
Mother nature made it green
Prettiest place you've seen
People don't know what they need

Open your window
What do you see
Do you remember
how it used to be

One of the first songs using the term “ecology”, another worrying about how people use nature putting money above all.

you can hear some songs in youtube:
Treetop flyer
Crossroads/You Can't Catch Me