Humans make artifacts (production) and can give their time and labor (services). Humans do not make natural resources, which are unrelated to either human time or human production. Humans may only modify natural resources. Natural resources are made by Nature and the energy to make them comes from geochemical, geophysical and solar energy. Humans cannot make petroleum, which once was living plants that have been processed for millions of years before humans existed, slowly becoming petroleum. Petroleum is a natural resource that we consider to be "nonrenewable" because it takes too long to make by the time scale that we can experience. But we can change where petroleum is located, and we can process it into components parts.