According to Limbaugh, some "environmental wackos" reject all forms of higher technology (electrical, mechanical, medicine, etc) and want the United States to abolish the automobile, stop using oil and gas, and revert to an agrarian society. Members of the Earth Liberation Front would be an example of those he might characterize "environmental wackos", since they participate in what many define as terrorist acts against corporations they perceive as unfriendly to the earth.
However, he extends the use of the term to describe a much broader segment of the environmentalist movment; thus, other environmentalist policies and principles he attributes to "environmentalist wackos" include: ignoring economic consequences of environmental laws; ignoring or avoiding any cost/benefit analysis regarding environmental policies; placing an equal or higher value on animal life than on human life; suggestions that animals are "just as intelligent" as humans; relying on lawsuits and laws to solve environmental problems, rather than relying on the marketplace. Thus, by many definitions, he would characterize the vast majority of environmentalists as "wackos". He also often accuses "environmentalist wackos" of using environmentalism as an excuse for the government to gain more property and more control over our lives.
Those who oppose Limbaugh's use of this kind of language identify his use of the term as a sophomoric example of ad hominem: by describing persons holding a certain viewpoint as "wackos", Limbaugh attempts to eliminate any intellectual obligation he might have to refute any of their arguments. Some may suggest that so-called "radical environmentalists" practice the same by characterizing Limbaugh as "radical right wing", although "wacko" is generally a much stronger assertion of value than "radical".
Limbaugh presents news stories with opinions which are unfavorable to theories and beliefs that those he characterizes as "environmental wackos" presumably hold.