The purpose of this paper is to understand the long run demand for energy-related environmental quality, its influence on legislation and on transitions to low polluting energy sources. It starts by presenting a simple framework of the relationship between the demand for and supply of environmental quality, environmental legislation and energy. This forms the structure for presenting a series of episodes in British history where a demand for improvements in energy-related environmental quality existed. This analysis proposes that markets can drive transitions to low polluting energy sources, in specific economic conditions. However, most probably, governments will need to push them, and this cannot be expected without strong and sustained demand for environmental improvements. Yet, while demand is a prerequisite, it is not enough. It must also be spearheaded by strong, creative and sustained pressure groups (i.e., powerful lobbying and the weakening of the counter-lobby) to introduce legislation, to enforce it and to avoid it being over-turned by future governments.