ScopeThe term encompasses more than the production and consumption of goods and services, including a shift from fossil fuels to the use of renewable energy, and the role of diversity as a characteristic of resilient and productive systems. It includes discussion of the role of money and finance as part of the wider debate, and some of its pioneers have called for a revamp of economic performance measurement tools.
 OriginsThe circular economy is grounded in the study of feedback rich (non-linear) systems, particularly living systems. A major outcome of this is the notion of optimising systems rather than components, or the notion of ‘design for fit’. As a generic notion it draws from a number of more specific approaches including cradle to cradle, biomimicry, industrial ecology, and the ‘blue economy’. Most frequently described as a framework for thinking, its supporters claim it is a coherent model that has value as part of a response to the end of the era of cheap oil and materials.
 Moving away from the linear modelLinear “Take, Make, Dispose” industrial processes and the lifestyles that feed on them deplete finite reserves to create products whose fate is, in the vast majority of cases, to end up in landfill or in incinerators.
This realisation triggered the thought process of a few scientists and thinkers, among whom was Walter R. Stahel, an architect, economist and one of the founding fathers of industrial sustainability. Credited with having coined the expression “Cradle to Cradle” (in contrast with “Cradle to Grave”, illustrating our “Resource to Waste” way of functioning) in the late 1970s, Stahel worked on developing a “closed loop” approach to production processes and created the Product Life Institute in Geneva more than 25 years ago.
 Creating the circular frameworkIn their 1976 research report to the European Commission in Brussels ‘The Potential for Substituting Manpower for Energy’, Walter Stahel and Genevieve Reday sketched the vision of an economy in loops (or circular economy) and its impact on job creation, economic competitiveness, resource savings and waste prevention. The report was published in 1982 as a book “Jobs for Tomorrow, the Potential for Substituting Manpower for Energy”.
Considered as one of the first pragmatic and credible sustainability think tanks, the main goals of Stahel's institute are product-life extension, long-life goods, reconditioning activities and waste prevention. It also insists on the importance of selling services rather than products, an idea referred to as the “Functional Service Economy” and sometimes put under the wider notion of “Performance Economy” which also advocates “more localisation of economic activity”.
In broader terms, the circular approach is a framework that takes insights from living systems. It considers that our systems should work like organisms, processing nutrients that can be fed back into the cycle – whether biological or technical - hence the “closed loop” or “regenerative” terms usually associated with it.
 Emergence of the ideaThe generic Circular Economy label can be applied to, and claimed by, several different schools of thought, that all gravitate around the same basic principles which they have refined in different ways. The idea itself, which is centred on taking insights from living systems, is hardly a new one and hence cannot be traced back to one precise date or author, yet its practical applications to modern economic systems and industrial processes have gained momentum since the late 1970s, giving birth to four prominent movements, detailed below.
 Founding principles
 Waste is FoodWaste does not exist… the biological and technical components (nutrients) of a product are designed by intention to fit within a materials cycle, designed for disassembly and re-purposing. The biological nutrients are non-toxic and can be simply composted. Technical nutrients – polymers, alloys and other man-made materials are designed to be used again with minimal energy.
 Diversity is strengthModularity, versatility and adaptiveness are to be prioritised in an uncertain and fast evolving world. Diverse systems, with many connections and scales are more resilient in the face of external shocks, than systems built simply for efficiency.
 Energy must come from renewable sourcesAs in life, any system should ultimately aim to run on ‘current sunshine’ and generate energy through renewable sources.
 Systems thinkingThe ability to understand how things influence one another within a whole. Elements are considered as ‘fitting in’ their infrastructure, environment and social context. Whilst a machine is also a system, systems thinking usually refers to non linear systems: systems where through feedback and imprecise starting conditions the outcome is not necessarily proportional to the input and where evolution of the system is possible : the system can display emergent properties. Examples of these systems are all living systems and any open system such as meteorological systems or ocean currents, even the orbits of the planets have non linear characteristics.
 The circular economy frameworkThe circular economy is a framework that draws upon and encompasses principles from:
 BiomimicryJanine Benyus, author of “Biomimicry: Innovation Inspired by Nature”, defines her approach as “a new discipline that studies nature's best ideas and then imitates these designs and processes to solve human problems. Studying a leaf to invent a better solar cell is an example. I think of it as "innovation inspired by nature. Biomimicry relies on three key principles:
- Nature as model: Biomimicry studies nature’s models and emulates these forms, processes, systems, and strategies to solve human problems.
- Nature as measure: Biomimicry uses an ecological standard to judge the sustainability of our innovations.
- Nature as mentor: Biomimicry is a way of viewing and valuing nature. It introduces an era based not on what we can extract from the natural world, but what we can learn from it.
 Industrial EcologyIndustrial Ecology is the study of material and energy flows through industrial systems. Focusing on connections between operators within the “industrial ecosystem”, this approach aims at creating closed loop processes in which waste is seen as input, thus eliminating the notion of undesirable by-product. Industrial ecology adopts a systemic - or holistic - point of view, designing production processes according to local ecological constraints whilst looking at their global impact from the outset, and attempting to shape them so they perform as close to living systems as possible. This framework is sometimes referred to as the “science of sustainability”, given its interdisciplinary nature, and its principles can also be applied in the services sector. With an emphasis on natural capital restoration, Industrial Ecology also focuses on social wellbeing.
 Cradle to CradleCreated by German chemist Michael Braungart and American architect Bill McDonough, the Cradle to Cradle Design model considers that all material involved in industrial and commercial processes can be seen as nutrients, of which there are two main categories: technical and biological. Technical nutrients should include only materials that do not have a negative impact on the environment (so non-harmful synthetic ones are accepted), while Biological nutrients are organic and can be returned to the soil without specific treatment to decompose and eventually become food for the ecosystem. What we need are “completely healthful products that are either returned to the soil or flow back to industry forever”, say McDonough and Braungart.
- Waste = food
- Use current sunshine income
- Celebrate diversity
 Blue EconomyInitiated by former Ecover CEO and Belgian businessman Gunter Pauli, the Blue Economy is an open-source movement bringing together concrete case studies, initially compiled in an eponymous report handed over to the Club of Rome. As the official manifesto states, “using the resources available in cascading systems, (...) the waste of one product becomes the input to create a new cash flow”. Based on 21 founding principles, the Blue Economy insists on solutions being determined by their local environment and physical / ecological characteristics, putting the emphasis on gravity as the primary source of energy - a point that differentiates this school of thought from the others within the Circular Economy. The report - which doubles as the movement’s manifesto - describes “100 innovations which can create 100 million jobs within the next 10 years”, and provides many example of winning South-South collaborative projects, another original feature of this approach intent on promoting its hands-on focus.
 Towards the Circular EconomyIn January 2012, a report was released entitled Towards the Circular Economy: Economic and business rationale for an accelerated transition. The report, commissioned by the Ellen MacArthur Foundation and developed by McKinsey & Company, was the first of its kind to consider the economic and business opportunity for the transition to a restorative, circular model. Using product case studies and economy-wide analysis, the report details the potential for significant benefits across the EU. It argues that a subset of the EU manufacturing sector could realise net materials cost savings worth up to $ 630 billion p.a. towards 2025--stimulating economic activity in the areas of product development, remanufacturing and refurbishment.
 See also
- Appropriate technology
- Cradle to Cradle
- Life cycle assessment
- List of environment topics
- Regenerative Design
- Sustainable Development
- The Blue Economy
- Walter Stahel, “How to Measure it”, The Performance Economy second edition - Palgrave MacMillan, page 84
- Clift & Allwood, “Rethinking the economy”, The Chemical Engineer, March 2011
- International Society For Industrial Ecology http://www.is4ie.org/