Many people in the conservative part of America are saying that the environmental movement is false and over reacting. Preservationists want to prevent any further damage to the ecosystem by putting wilderness areas off limits to human economic activity.
Conservationists believe that wildlife and some limited economic activity can coexist in harmony.
Preservationists and developers are complete opposites, and conservationists fall out somewhere in-between. But when it comes to specific facts, that is where science can help determine what is true. For example, it is true that the Northern Spotted Owl population is threatened with extinction if the primeval forests upon which it depends are cleared for lumber. That is a fact that can be confirmed or unconfirmed by the methods of natural science. But whether the extinction of a species or ecosystem is a bad thing, or a worse thing than the loss of income and jobs by people who work in the timber industry is a judgment that depends on your own personal values and beliefs.