I love this poem. It is so appropriate, especially in these times:

Friend, if perhaps in a year or ten

You may want to walk this path again,

Then fail not to remove the trace

Of synthetic foil, cans or waste,

Plastics that no living thing can flourish on

Or traps you will not want to step upon

Else in times which are soon to come

Instead of beauty you will find a slum

And, perhaps, you will come to understand

How the splendour of our land

Was spoilt by your hand

Author unknown