The existing system in a very basic way works towards increasing people's standard of living. That's what the vast majority of the people on the Forbe's list get wealthy doing...proving goods and services to people. (Ill add over 70 percent of them did not inherit the business that put them on the list.)
If your interest is improving either standard of living or the environment what about our current system is it most necessary to change? There are the things we do directly through consumption, like dig materials out of the ground; but, how do you go about reducing things like that? Given the world we live in, I'd argue population reduction through increasing standard of living is one of the few realistic avenues open to us. There are at least two basic reasons for this: 1. people need to reach a certain economic level before they can think about the environment and 2. increasing peoples standard of living leads to them having fewer children.
I want you to imagine walking up to some guy in India who lives and works in one of those huge garbage dumps. Try to explain to him your ideas about global warming. He will think you are full of shit and ignore everything you say. You need to first create a level of economic stability before you can have that discussion.
This concept is called "Maslow's Hierarchy". Its the basic idea as people rise economically, there are better able to think about and address more general philosophical concerns that are beyond their immediate survival.
Secondly, as people's standard of living increase; as women go out and get careers; they have fewer children and they have them at an older age in life.
As I've mentioned before, we are seeing this phenomenon reflected in the demographics in a large number of countries from Russia to USA to Japan. In Japan, for example, women are staying at home into their 30's while they go out and get careers. I've already mentioned: the government of Japan calls this a crisis even though they have 127 million plus people crammed onto a handful of islands.
This fear of a demographic crisis is counter productive to those who'd like to see a natural and non oppressive way of reducing the worlds population. It leads to the artificial tension between improving standard of living and the environment at the same time...