There all all manner of notions in the idea of being Green.
Nature, wildness, money, sustainability, envy, hugging trees, pollution conservative business, nature protective politics, anti-drilling/cutting/digging/expanding blockades, Sir Gawain, recycling, paganism, enviro-activism, ecocapitalism, ... the list goes on.
After all is said and done, the basic value of greenness, which occasionally escapes practice, is sustainable relationship, or cultivating associations between ideas and creatures and earth in which every participant gets all of what is needed and at least some of what is wanted.
The Peoplegreen idea directs the two-footed part of right relationship and ecologicality back into the mirror wherein we see each other, and without which we cannot work well together, and gives it a catchy name so it is easier to talk about and spread around like the fertilizer it is.
I suspect that paying attention to how I consume, reuse, transport, recycle, spend, make conflict, war, and culture, and also refrain from doing all these things has to do with being Green. Paying this attention and then deepening understanding into action is what is required to green human relationships. This is what is meant by Peoplegreen.