This chapter considers some of the domains, practices and communities involved in environmental decision-making and some related needs for both teaching and learning. Some challenges are identified for educators in the context of environmental decision making: their changing roles, distribution of learners, needs for social learning, the role of distance learning and use of the Internet. Contexts of education, social learning and environmental decision making are first reviewed to see why structures such as Communities of Practice (CoPs) are needed. A case study is presented to help consider what can support teaching and learning environmental decision making. This case is about an Open University course produced by educators for and with other practitioners. Analysis of the case study and wider communities involved in environmental decision making focuses on three areas (i) what is meant by CoPs in these contexts, considering distinctions among different groups and communities, their purposes, characteristics and relationships (ii) design of supportive learning systems with online elements and (iii) conceptualising teaching and learning. The conclusion is that there is a need for teaching and learning to be viewed as an inseparable and complementary duality in which CoPs potentially have an important role.