Permaculture is a form of whole systems design based on the sustainability of natural systems, seeking to reproduce that sustainability in our living environment. Permaculture designs differ based on climatic factors, bioregion, organizational goals, personal preferences and other factors. They integrate "land, resources, people and the environment through mutually beneficial synergies – imitating the no waste, closed loop systems seen in diverse natural systems". It can hence be said that permaculture is, at its core, a set of thinking tools, in particular towards awareness of context, threats and opportunities. The holistic approach of permaculture integrates "agriculture, water harvesting and hydrology, energy, natural building, forestry, waste management, animal systems, aquaculture, appropriate technology, economics and community development". Permaculture was initially conceptualized by Bill Mollison and David Holmgren in Australia during the 1970’s. Mollison and Holmgren sought to reverse the environmental degradation that seemed to follow closely on the heels of modern development while simultaneously increasing the sustainability of food production systems by promoting localized self-reliance. Though it was developed out of sustainable agriculture, permaculture design is hypothetically applicable to any field of human endeavor. The very term "permaculture" itself was first used to mean "permanent agriculture," it is now applicable to all realms of design and is now considered to mean "permanent culture". In recent years, social and economic permaculture have been receiving more attention. In a strict sense, "permaculture" refers to the system developed by Mollison, Holmgren, and their successors. However, some use the term "permaculture" in a broader sense to refer to practices of indigenous and traditional peoples around the world, such as chinampas from Mexico or zai from West Africa. Contemporary innovators are often also included under the permaculture umbrella such as Masanobu Fukuoka and Sepp Holzer.