Materialism, conspicuous consumption, and the worship of 'more' are the disease. Climate change, species extinction, ocean acidity, polluted waterways, feedlots...on and on, are all symptoms of the disease and treating symptoms in most cases is worth less than zero because it just diverts one's attention away from the underlying disease's progression.
What to do? Of course speaking out against the outrageous destruction of our home is a beginning and an acknowledgement of one's understanding the cause of the problem. But doing is harder, doing requires changing and often being different. We live in a culture of fear, fear of the unknown, fear of body odor, fear of being different...fear. Freedom from fear, even for a moment, creates the space and time needed for individual action.
Action can start small and grow. The beginning of the path 'out' for me was the step into the cash economy. Buying local and spending cash is a small way to resist, is an empowering first step. For me it feels good to have less, to want less, to 'drop out' of the capitalist system that is consuming our mother earth, to read, to learn, to live freely through small acts of resistance.
Today Guy McPherson's site Nature Bats Last ran a great, but overly long, anarchist essay in favor of resistance to the machine. It concluded that, "Calculating people would not enter this fight, because we have so little hope of winning.We continue fighting, because we hate all authority, and love freedom, which cannot be given, but must be taken."