The ways in which humans affect and are affected by their environments have been studied from many different perspectives over the past decades. However, it was not until the 1970s that the discussion of the ethical relationship between humankind and the environment formalized as an academic discipline with the emergence of environmental ethics. A few decades later, environmental health emerged as a discipline focused on the assessment and regulation of environmental factors that affect living beings. Our goal here is to begin a discussion specifically about the impact of modern environmental change on biomedical and social understandings of brain and mental health, and to align this with ethical considerations. We refer to this focus as Environmental Neuroethics, offer a case study to illustrate key themes and issues, and conclude by offering a five-tier framework as a starting point of analysis.