People commonly use the term environment in the first, most narrow sense—to mean a nonhuman or “natural” world apart from human society. This is unfortunate, because it masks the vital fact that people exist within the environment and are part of nature. As one of many species on Earth, we share dependence on a healthy, functioning planet.
The limitations of language make it all too easy to speak of “people and nature” or “humans and the environment” as though they were separate and did not interact. However, the fundamental insight of environmental science is that we are part of the “natural” world and that our interactions with the rest of it matter a great deal. Understanding our relationship with the world around us is vital because we depend utterly on our environment for air, water, food, shelter, and everything else essential for life. Throughout human history, we have modified our environment.
By doing so, we have enriched our lives; improved our health; lengthened our life spans; and secured greater material wealth, mobility, and leisure time. Yet many of the changes we have made to our surroundings have degraded the natural systems that sustain us. Air and water pollution, soil erosion, species extinction, and other impacts compromise our wellbeing and jeopardize our ability to survive and thrive in the long term.