The rapid rise and success of environmental law and regulation has come with the price that the content and legitimacy of the underlying concepts and principles of environmental protection and governance have been given insufficient attention and time to evolve. Consequently, environmental law could not ‘expand organically’ in view of the rapidity, urgency and its political content and context. Yet it is the presence or absence of such legal conceptual underpinnings that will condition whether environmental law develops into a fully fledged and permanent body of law, or whether environmental protection is to be merely a factor in a problem-specific context that will be taken into account in a diversity of established substantive contexts. This chapter describes how corpus linguistics and concordances-based methodologies were used to examines specific terms typically associated with the impact of human activities on the environment, and in order to reveal how conceptual meanings have shifted throughout the twentieth century and from one decade to the other since the 1960s.