bitte übersetzten:            1. Introduction
Irresponsible and unethical consumption has disharmonized the exchange of resources between the economy and the environment. It would not be wrong to say that our overconsumption of resources has pulled us into a state of resource deficit with an alarming ramification across the social, economic, cultural, and environmental frontiers. The circular economy (CE) has appeared as an innovative approach to resource utilization with an emphasis on the ethical and more rational use of these resources. Focusing on factors like extending the life of resources and maximizing the value of resources would help to keep resources within the loop of production and consumption (P&C) and could reduce the pressure on the existing stock of resources. A shift from this contemporary and prevalent linear economy (LE) mode of consumption, which focuses on take–make–dispose, to the circular concept of take–make–reuse methodology is a mandate to achieve sustainable development.
Even though the CE concept is gaining traction in the national as well as global arenas, the domain still has not diffused well; [1] conducted a comparative analysis of the perception and awareness regarding the CE between Nepal and the USA, which concluded that respondents across the sampled countries were unaware of the CE and its implications for their organization. Similarly, a survey by Liu et al. [2] in China concluded that the respondents thought of CE as a waste-management approach which defines their limited awareness of the CE philosophy; and in the Netherlands, only 9% of the respondents claimed to have exact knowledge of the CE [3].
1.1. Origin of the Circular Economy Concept
The literature has not precisely stated the origin of the CE concept; the circular domain was inspired with the manifesto of preserving natural resources and focuses on the concept of a cyclical closed-loop system [4]. Though the term circular economy was not precisely coined in early ages, enough literature could be found which focused on resource conservation, and these could have been the building blocks for the evolution of circular economy principles.
Winans et al. [5] writes that the U.S. professor John Lyle, William McDonough, German chemist Michael Braungart, and Walter Stahel were the originators of the concept. Luis and Celma [6] stated that Walter R. Stahel and Geneviave Ready were the first to establish the concept of CE in 1976. Pearce and Turner [7] formally introduced the CE concept in their economic model, where they stated the three economic functions of CE, those were, environment-resource supplier, waste assimilator, and source of utility [8]. The world expressed its concern for environmentalism when the Brundtland Report WCED (1987) stressed the sustainable development and emphasized the need to work globally on eliminating unsustainable practices so that we can take care of our future generations. Winans et al. [5]) noted that Silent Spring by Rachel Carson, the thesis of the Club of Rome entitled The limits to growth, and Barbara Ward and Kenneth Boulding’s metaphor of spaceship earth had inspired the bringing of the concept of CE. Cautisanu et al. [9] wrote that whereas the concept of sustainability was initiated during the 1990s, the evolution of circular philosophy has been just a decade in discussion.
Murray et al. [4] claimed that in 1996 Kenneth Boulding was the first to shed light on circular ecology. In China, the concept of the CE was first proposed in 1998 and was formally accepted by the central government as a new development strategy in 2002 [10]. Mas-Tur et al. [11]) also echoed that the CE was first proposed in 1998 by Chinese academicians and adopted by the government in 2002. China has integrated the concept of the CE for the sustainability in their 11th and 12th “Five Year Plan” [4]. Homrich et al. [12] describes China to be dominating CE-related publications globally. China significantly used circular philosophy to reduce the pressure of its economic developmental polices on natural resources [13].
1.2. Academic and Non-Academic Developments in a Circular Economy
A paper by Homrich et al. [12] to assess the trends and gaps on integrating pathway of circular economy listed six journals that most published CE-related papers, to name some: The Journal of Cleaner Production, Resources Conservation and Recycling, The Sustainability Journal, and Journal of Industrial Ecology, and it was noted that the number of publications related to CE has increased since 2013. The count of research papers related to CE is on rise, in comparison to 30 in 2014, the published papers reached more than 100 in 2016 [14]. Mas-Tur et al. [11] adds that the annual publication related to CE increased from 4 in 2006 to 809 in 2018. A Scopus search on CE terminology shows a 50% increase in academic publication over past five years and significant growth was observed between 2015 and 2017 [15].
Though the concept of the CE was initially introduced by the Western scholars, later the Chinese scholars profoundly worked on the CE domain after gaining support from their government [16]. The Delft University of Technology (Delft, The Netherlands) and Chinese Academy of Sciences (Beijing, China), respectively, are the most productive and influential institutions in conducting CE-related publications; meanwhile, China tops the position of being the most productive and influential country in CE related publications followed by the UK, Italy, Spain, the Netherlands, and the USA [11]. The period of 2004–2015 was dominated by Chinese scholars [16].
Winans et al. [5] noted multiple incentives and models that would foster the inclusion of the CE, while countries like Japan and Singapore focused on the creation of the eco-city. Germany in the early 1990s aimed the management of resources and raw materials through CE principles, and China in the late 1990s promoted the concept of eco-industrial parks. In the context of North America, the CE philosophy was used to perform reduce, reuse, and recycle programs and to conduct product lifecycle studies. In North America, corporate houses were found to be taking active approaches to incorporate the circular philosophy in their operations and strategy while the regulatory institutions have been inactive to the CE.
Though the circular concept came to existence before 1990, it was popularized by think-tanks like the Ellen MacArthur Foundation (EMF) [17]. The EMF (2013) [18] has played a crucial role in the development of the CE in the global platform. NGOs and INGOs across the globe like the World Economic Forum (WEF), United Nations, and business consulting firms like Mckinsey & Company, Circular Economy, Accenture, KPMG, and Deloitte are also producing with numerous research works in the field of the CE to support the transition from the LE to the CE. In 2018, the EMF in collaboration with various government and non-governmental agencies initiated the platform for Accelerating the Circular Economy [19]; the sole purpose of the collaboration was to bring the governmental, non-governmental, and big business houses together for a commitment towards the implementation of the CE.
1.3. Conceptual Development in Circular Economy
Numerous scholars and practitioners were found using terminologies that infer a CE. Pauliuk [20] writes, over the last decade, the CE has gained significant traction to decouple economic development with natural resources. The CE has become a hot topic of discussion amongst the businesses, governments, academicians, and NGOs [21]. With the passage of time, the domain of the CE has proliferated, it started with the environmental concern, then incorporated economic domains and now has encapsulated the social aspects [4].
In fact, Kirchherr et al. [22] writes, the meaning and the use of the CE could be different to different people and this circular economy babble often creates confusion in materializing the precise definition of the CE. The CE has been evolving throughout time and is based on multiple domains and schools of thought [23]; with the passage of time, numerous scholars across different disciplines have written literature on the circular economy which has influenced our understanding of the CE [24]. Garces-Ayerbe et al. [25] stated that the CE concept is novel and is emerging.
The concept of the CE which started with waste management and the end of life cycle (EOL) has now incorporated a diverse field; numerous scholars have focused on managing the resources life cycle extension (RLES) and circular design strategies. A CE helps to bridge the gap between the waste and the resource management. Contrary to the LE, which focuses on cradle-to-grave, CE emphasizes on cradle-to-cradle [26]. Braungart and his team came up with the philosophy from “cradle-to-grave” to “cradle-to-cradle”, and Stahel put forth the concept of a closed-loop strategy [27]. The CE promotes cyclical thinking, instead of having an open-ended conception of value-added chain, CE focuses on the minimization of the use of the virgin materials [28]. Ghisellini et al. [29] asserts that the increasing attention the CE is gaining globally by promoting a closed-loop strategy can achieve resource efficiency.
Yuan et al. [10] wrote, CE is beyond ecological orientation and also precisely stresses economic opportunities that could be achieved from the CE. It is a transdisciplinary domain which has evolved through and envelopes numerous supporting ideas. The CE focuses on the restorative and regenerative cycle in contrary to an LE which is defined as a cowboy economy by Boulding [30] which emphasizes on the take–make–dispose. Waste is seen as a resource and no waste exists in a circular concept [31].
The CE is based on three principles: (a) design out waste and pollution, (b) keep products and materials in use, and (c) regenerate natural systems (EMF, 2013). [32] described the CE as a cyclic system where the goods after their end of life are turned into resources for others. Murray et al. [4] alerts us to the infancy of the CE domain and stresses the requirement of definitions which incorporate ecological and social benefits. Since the time of inception, the domain of the CE has been diversifying and cocooning numerous concepts from diverse domains, often creating confusion.
The circular economy is a multidisciplinary domain which is inspired by and evolving through incorporating numerous schools of thought [33,34]. Antikainen et al. [35] asserts ecological economics, environmental economics, and industrial economics have been antecedent to the development of the CE concept. Concepts like The Natural Step in 2020 by Karl-Henrik Robèrt, Product-service systems in 2006 by Arnold Tukker and Ursula Tiscnher and Cleaner Production in 2004 by Richard S Stevenson and J. Warren Evans were cited in Borrello et al. [33] to highlight their importance in the development to the CE. Along with the passage of time, numerous scholars have provided CE definitions and it could be inferred that the dimension of the CE has been diversifying and inclusive since then.
1.4. Studies Related to the Concept and Taxonomies of the Circular Economy
With traction increasing in the CE field, the research related to CE is gaining momentum [33,36] The number of publications related to the CE has increased significantly since 2017 [37]. An online search of the CE produced 20,570 results in 2008, which as of now extracted 5.74 million results [38]. Most of the academic research follows bibliometric analysis [6,16,37,39,40] whereas the researchers Alhawari et al. [41] and Friant et al. [38] carried systematic literature reviews with critical content analysis. Further, the number count of peer-reviewed paper in the databases (Scopus, WoS, Google Scholar, ScienceDirect) is also increasing significantly. A time-range categorization of CE concept development has been carried out along with the incorporation of the umbrella concept to assess the growth and proliferation of CE concepts across time ([6,16,37,38,39,40]).