Sustainable living describes a lifestyle that attempts to reduce the use of Earth's natural resources by an individual or society. Its practitioners often attempt to reduce their ecological footprint (including their carbon footprint) by altering their home designs and methods of transportation, energy consumption and diet. Its proponents aim to conduct their lives in ways that are consistent with sustainability, naturally balanced, and respectful of humanity's symbiotic relationship with the Earth's natural ecology. The practice and general philosophy of ecological living closely follows the overall principles of sustainable development. One approach to sustainable living, exemplified by small-scale urban transition towns and rural ecovillages, seeks to create self-reliant communities based on principles of simple living, which maximize self-sufficiency, particularly in food production. These principles, on a broader scale, underpin the concept of a bioregional economy. Sustainable living is fundamentally the application of sustainability to lifestyle choices and decisions. One conception of sustainable living expresses what it means in triple-bottom-line terms as meeting present ecological, societal, and economical needs without compromising these factors for future generations. Another broader conception describes sustainable living in terms of four interconnected social domains: economics, ecology, politics, and culture. In the first conception, sustainable living can be described as living within the innate carrying capacities defined by these factors. In the second or Circles of Sustainability conception, sustainable living can be described as negotiating the relationships of needs within limits across all the interconnected domains of social life, including consequences for future human generations and non-human species. Sustainable design and sustainable development are critical factors to sustainable living. Sustainable design encompasses the development of appropriate technology, which is a staple of sustainable living practices.