I've sung this one a few times and use the chorus if there's an "audience" who want to sing a lot, otherwise I just repeat the chorus verse at the end. I do have a tune but would have to email it to you if you wanted it.

CHILDREN OF THE EARTH

"Chorus"
We are children of the earth, air fire and water
[But] don't you know that they're not ours to keep?
For we borrow them at birth, share them for a season
Give them back when we lay down to sleep.

We are children of the earth, it gives us grain to feed us
But don't you know that it's not ours to keep?
Though it shelters us from storms, with stars above to lead us
Stars will fade as we lay down to sleep

Chorus

We are children of the air, the breath that moves within us
But don't you know that it's not ours to keep?
Though it raises us on high, to soar on wings with eagles
We breathe out and we lay down to sleep

Chorus

We are children of the fire, it gives us heat to warm us
But don't you know that it's not ours to keep?
For the sun shines but a day and then the dusk enfolds us
The sun will set as we lay down to sleep

Chorus

We are children of the water, the blood that courses through us
But don't you know that it's not ours to keep?
For the tides they ebb and flow as the moon she calls unto them
The tides will ebb as we lay down to sleep

Chorus

So treat this earth with care, the air, fire and water
Don't you know that they're not ours to keep?
We cannot own these things, they're not ours to be broken
Our children need them when we lie asleep.