In reply to lizheath:
It seems a very consumerist approach you have towards the great outdoors- having to sell them a way they'll want to take their rubbish home.
I guess that's the contemporary take on things. Once upon a time, societal norms included overarching principles such as respect and consideration. Guided by these principles on a subconscious level, if I ventured out in the countryside then my environmental 'awareness' was just another manifestation of those principles in action. I don't think it was the countryside that led to it.
There are many instances today where people are enticed into the hills by challenges such as the three peaks, which are widely viewed as anything but environmentally friendly. There are sportives whose routes can be determined by the trail of gel wrappers. Examples of how the countryside is nowadays marketed as an arena for personal challenge. From the rubbish left behind, in many cases, the need to complete/achieve trumps the need for environmental consideration. I guess you could argue that the competitors are not the sort of people out in the hills for extended periods, but I'm not convinced.
If you have to sell an idea to create environmental awareness, I'd guess it would be more likely to be situation specific in our consumerist age.