Most likely if you are reading this article you already regard environmental policy as a significant issue. However, to be considered for governmental action, you must first have a clearly defined problem. It is not enough to simply say "we need to help endangered species!" Instead, the problem must be defined in terms of potential actions that can be taken. That is, the process of defining a problem includes identifying the specific area that needs to be addressed and potential solutions for that problem. To be considered later for agenda, these things have to be defined in terms of their expanse (national, local) and influence (business, neighborhoods, cities, etc). The early discussion on the topic will serve to set up the rest of the policy making, establishing the basic rhetoric used to promote the cause and identifying the key issues and points of emphasis.
For instance, the expanding development in Florida's wetlands is destroying the habitats of the local wildlife, endangering a variety of species. In the 1990s, a lot of discussion went into why this was occurring and what could be done about it before any action could take place. After a while, the issue became adaquately identified and framed into a form that could make an argument for potential action. Things like establishing and expanding National Forests, restricting development, and placing bans on hunting were all discussed and defined so that they could be presented to players in the government.
Note that this part of policy formation is the one you have most control over; it is the one that takes place in the general culture, media, and everyday conversations. Grassroots efforts and environmental organizations are key to this defining process as are researchers, professionals, and various public activist leaders who specialize in environmental regulation.