Well, those visiting Copenhagen will be rewarded for such 'sustainable' activities.
Many of us have called out Dublin city centre's litter problem.
But with millions of tourists passing through our streets every year, should we follow in Copenhagen's footsteps?
The Danish capital has started a new initiative encouraging visitors to travel by public transport, pick up rubbish or do some gardening for rewards:
But it's not just a case of swapping A for B.
If you bring plastic waste to the National Gallery of Denmark for example - you can take part in an art-making workshop.
And those who help out at an urban farm can taste the seeds that they sow.
The pilot project runs until the 11th of August.
