The greenhouse effect(GHE) is a concern to everyone on this planet.Citizens need to be scientifically literate in relation to this phenomenon in order to participate in democratic decision-making and to take appropriate actions in their daily lives. As the GHE is a global issue it will require collective and individual actions to prepare for the likely climatic changes and to reduce the further impact of the GHE.The main focu of this book is on high school students'' beliefs about, understandings of the GHE and their intentions to act in ways that would reduce greenhouse gas emissions. High school students strongly believe that the GHE is real and affecting the climate at present and will also affect it in the future. They consider that the GHE is a relatively important social issue and they believe that governments should conduct programmes to raise community awareness and enact strict laws to reduce the release of greenhouse gas. The Propositional Knowledge Statement (PKS) that is science concepts necessary for an understanding of the GHE in terms of its causes, effects, mechanism and actions that can be taken to reduce greenhouse gas emission.