Abstract: Many environmental educators have been trying their best to integrate environmental education into the formal education sector since the early 1970s. A variety of supplemental instructional materials have been developed by concerned environmentalists to help citizens in general and more specifically school students, to understand appropriate ways to care for the Earth. Interdisciplinary, multidisciplinary and transdisciplinary approaches have been the dominant ones undertaken so far to achieve this goal. Differences between the three approaches are detailed in the paper. Most environmental educators are familiar with the first two approaches. This author provides an argument from his researches that the transdisciplinary approach might be the best one to raise environmental literacy among citizens.