Impacts on semi-natural ecosystems stem from: human numbers X resource demands. Larger human populations that use fewer resources per person can have an equivalent environmental impact to smaller human populations that use larger amount of resources per person. Consider impacts of many African populations compared to impacts of North American populations.
The point is simply that consumption per individual is the critical element in determining impacts.
Conservation effort must be directed at consumption to reduce impacts. As long as consumer demand is strong, suppliers will continue to deliver resources to those consumers. As long as consumers continue to demand petroleum products, wells will be drilled and pumped and pipelines will flow and be built and expanded.
“Green” consumers must analyze the products that they purchase to understand the resources that form components of those products and, further, they must learn the impacts that result from the procurement of those resources. Cell phones and other mobile devices incorporate several rare earth metals that are extracted from various environments. The extraction can be very damaging to the environments and to the cultural and social structures depending on those environments. Buying, or throwing away, a cell phone is not a morally neutral act.
We humans, especially in the developed nations, must face the fundamental contradiction that an economic system that depends on consumption is contrary to living softly on the land. Our best option is to selectively reduce consumption by eliminating goods that have the greatest damaging impacts from their extraction and from their collateral cultural effects.