In a 'greenies world' we would see no development, no population growth, and thus no increase in pressure on the world's forests or increases in the concentration of atmospheric CO2. The problem however is that unthinking greenies are succumbing to the appeal of governments who utilise their deluded and misguided ideas to make all types of demands upon the productive end of the economy.
Consider the policy of reducing the consumption of hydrocarbons, whether coal or natural gas. It has resulted in the pursuit of more renewal options like wood waste, biofuels and geothermal. The problem with some of these options is that, whilst they might reduce CO2 consumption, they have other impacts on other areas, some of which are equally precious to environmentalists. i.e. Consider rainforests. The biofuels revolution has pushed up the demand for grains, and thus lands to grow them. This has displaced existing food production in the West, and resulted in developing countries clearing large tracts of forest in order to develop more food production capacity, as well as biofuel capacity.
Greedy capitalists will of course get the blame for their short-sighted actions, but the reality is that the greenies would have failed to adopt their ideas, which are misguided in themselves, but equally distortive when you consider their impact.
For more tips on how to be a well behaved environmentalist, see my global warming blog.