Additionally, I would add that one of the most prominent reasons that Buddhists are often advocates for nature and animals is because of the core teachings upon interdependence. It's not so much protecting the trees out of a sense of moral superiority but rather a normal extension of being awake to the multi-layered essence of life on Earth. When we awaken to the reality that our very existence is dependent upon a healthy planet then it becomes obvious that protecting the trees (and the rest of nature) is an extension of being alive. It is also true that when we cultivate compassion for others we understand how balancing nature is integral in helping to reduce their suffering.
Thich Nhat Hanh says in his new book, "The World We Have" that, The situation the Earth is in today has been created by unmindful production and unmindful consumption. We consume to forget our worries and our anxieties. Tranquilising ourselves with over-consumption is not the way. Just like eating a bunch of sugar instead of a meal will give you a rush of artificially inflated energy followed quickly by a depressing physical crash; so to will trashing out planet lead to a crash of the "good times" followed by a deep and painful awakening to a very different world.
I've never been much of a doomsday alarmist but the over-consumption of just about everything by humanity is really starting to show and take its toll. Our greed has over-fished our oceans, poisoned our air, desecrated our forests and swollen our Earth with over-population. It is an unsustainable lifestyle and that centuries long, unskillful behavior is harvesting some sobering karma. I'm not the kind of person who stands on the corner of a busy street, ringing a bell and warning of the "end of the world" but I do see a radical change coming, and I believe awareness is the best tool to adapting.
I can see a time in the near future when our instant, electronic world will crash and fail like an old car in the Mohave desert. This will return us to a simpler way of life where the grocery store is a garden, where the animals are more valuable than cars and where being able to work with others in co-operation will mean the difference between survival and calamity. It won't destroy all of humanity but we'll have to relearn how to live a life similar to that before the industrial revolution, which will be a tough transition for some who lived the delusion that the party would go on forever. We lived through the ugly days of the "Dark Ages" when life was bleak and people died in droves and currently we're living a life of excess that is the exact opposite.
And interestingly, I think it might be a good thing for humanity to get this wake up call because it'll force us to hit the reset button on how we see the world and our resources. It will also mean that we don't have to live again in the "Dark Ages" but we also can't live the life of never-ending consumption either. We'll have to find that sweet spot, or the middle ground where life is the most sustainable. It'll be a shock at first but in the end I think we'll see that living the "hungry ghost" life of over-consumption was never really realistic in the first place.