Environ 201- chapter 1: science and sustainability: an introduction to environmental. Environment: the sum total of our surroundings, including all living and nonliving things with which we interact. Environmental science: the scientific study of how the natural world functions, how our environment affects us, and how we affect our environment. Natural resources: any of the various substances and energy sources that we take from our environment and that we need in order to survive. Renewable natural resources: natural resources that are virtually unlimited or that are replenished by the environment over relatively short periods (hours to weeks to years) Nonrenewable natural resources: natural resources that are in limited supply and are formed much more slowly than we use them. Ecosystem services: an essential service an ecosystem provides that supports life and makes economic activity possible. Ecosystems naturally purify air and water, cycle nutrients, provide plants to be pollinated by animals, and receive and recycle the waste we generate.