"Take only pictures, leave only footprints."
It's a pretty simple motto that a lot of parks and natural areas use as a guideline to minimize visitors' impact.
The concept is basic. Don't take home pieces of a natural treasure as you leave the park, and don't leave your refuse laying around when you do leave.
Nowadays, conservation is a lot more complicated. We talk about footprints, not it terms of tracks left in the dust, but as a measure of our carbon emissions into the environment. We have politicians who almost unilaterally talk about the importance of climate change, but are miles apart on what we should do about it. There are far too many elected leaders who feel talking about global warming is enough, and that the economic setbacks of weaning our country off of fossil fuels are too great to actually enact any kind of climate legislation.
And why bother changing? After all, there are still plenty of mountains in Appalachia we can destroy to get more coal, and plenty of tar sands to be mined in Canada. Who'll miss mountains anyway? Never mind the fact that it takes two tons of sand to produce one barrel of oil, or that you'd have to go nuclear to come up with a more destructive process than mountain-top removal coal extraction. (It's just what it sounds like. Forest-covered mountains are systematically razed to the ground, coal extracted and the refuse simply shovelled over into the adjoining valley. The process destroys a mountain, a valley and whatever freshwater streams or lakes created the landscape in the first place. Small price to pay for some lumps of coal and "American jobs.")