I thought I'd add this excellent Ted Talks clip as an add-on to the previous post by Alina (if you haven't read it already - perhaps go do so, and then come back to watch this!).

I really like the concept of our environmental impact being positive, rather than just the traditional 'less bad'. In this Ted Talks presentation, Janine Benyus talks about design, and, in particular, about design that imitates natural systems - a concept called 'Biomimicry'. Everything in nature works efficiently. All organisms, with the exception of 'clever' humans, have or develop symbiotic relationships with each other. Energy is constantly recycled, and, as opposed to our typical consumer product, all 'products' in nature, even in death, give life to the next generation.