Here we describe several useful strategies to a variety of unusual α-amino acid derivatives and peptides based on “building block” approach. These building blocks are suitable for modification at an amino acid as well as at a peptide level. Moreover, these methods have embedded several points for diversification and are capable of producing a library of modified amino acids and peptides. We have employed highly atom-economic processes such as the Diels–Alder reaction, [2 + 2 + 2] cycloaddition, Suzuki–Miyaura cross-coupling, and olefin metathesis as key steps to assemble various unnatural amino acid derivatives and peptides. In some instances, we have used rongalite to generate Diels–Alder precursors.
In 1992, one unambiguous result of the UNCED conference was the need for changing consumption and production patterns, with affluent countries taking the lead. 20 years later, at the 2012 UNCSD, little is left over and instead the “green economy” has been the theme pursued by the OECD, the EU and other countries. So the question needs to be answered if this is finally an attempt to put into practice what was promised 20 years ago, or another diversion from what needs to be accomplished. Sustainable development is still a convincing concept, if the original definition is taken, avoiding the confusion caused by partisan interests reinterpreting the concept. Focussing on human needs fulfilment and respecting environmental limits, it can still guide strong sustainable consumption. Green economy/green growth, on the other hand, is a new terminology for what is known since 40 years as ecological modernisation. It is indeed overdue, but with its focus on efficiency and innovation it cannot guarantee to fulfil the Brundtland sustainability criteria. A factor analysis based on the I = P*A*T formula demonstrates how optimistic the assumptions regarding future technologies must be to support the green growth concept. Consequently, the authors pledge for a pragmatic, risk avoiding approach by slimming the physical size of the economy. This requires ‘strong sustainable consumption’ (including production as resource consumption), which in turn requires a change of the societies' institutional settings (formal and informal, mechanisms and orientations). Finally some elements of a strategy towards this end are pointed out, with special emphasis on the role of non-governmental organisations NGOs. Through networking and advocacy they can both stimulate bottom-up action and mobilise the pressure necessary for the institutional changes which are needed to mainstream strong sustainable consumption.
A 'circular economy' would turn goods that are at the end of their service life into resources for others, closing loops in industrial ecosystems and minimizing waste (see 'Closing loops'). It would change economic logic because it replaces production with sufficiency: reuse what you can, recycle what cannot be reused, repair what is broken, remanufacture what cannot be repaired. A study of seven European nations found that a shift to a circular economy would reduce each nation's greenhouse-gas emissions by up to 70% and grow its workforce by about 4% - the ultimate low carbon economy (see go.nature.com/biecsc).
While the terms Circular Economy and sustainability are increasingly gaining traction with academia, industry, and policymakers, the similarities and differences between both concepts remain ambiguous. The relationship between the concepts is not made explicit in literature, which is blurring their conceptual contours and constrains the efficacy of using the approaches in research and practice. This research addresses this gap and aims to provide conceptual clarity by distinguishing the terms and synthesising the different types of relationships between them. We conducted an extensive literature review, employing bibliometric analysis and snowballing techniques to investigate the state of the art in the field and synthesise the similarities, differences and relationships between both terms. We identified eight different relationship types in the literature and illustrated the most evident similarities and differences between both concepts.
In this paper, we take a political economy perspective on barriers that inhibit a transition beyond the growth-paradigm – that is, we frame transition barriers as looming conflicts of interest. Specifically, we investigate potential transition barriers within three case studies. First, unemployment represents the most commonly cited reason why economic growth is considered indispensable. Second, alternative indicators to Gross Domestic Product (GDP) have not succeeded in replacing GDP as a standard metric of economic welfare. Third, pension schemes rely on economic growth to offset demographic change. In each of these three examples, we identify actor-interest constellations that foster the status quo of a growth economy. We conclude that compensating some of those actors who would presumably be worse off in a post-growth economy may be necessary – though not sufficient – for a transition.
Circular economy (CE) is currently a popular concept promoted by the EU, by several national governments and by many businesses around the world. However, the scientific and research content of the CE concept is superficial and unorganized. CE seems to be a collection of vague and separate ideas from several fields and semi-scientific concepts. The objective of this article is to contribute to the scientific research on CE. First, we will define the concept of CE from the perspective of WCED sustainable development and sustainability science. Second, we will conduct a critical analysis of the concept from the perspective of environmental sustainability. The analysis identifies six challenges, for example those of thermodynamics and system boundaries, that need to be resolved for CE to be able to contribute to global net sustainability. These six challenges also serve as research themes and objectives for scholars interested in making progress in sustainable development through the usage of circular economy. CE is important for its power to attract both the business community and policy-making community to sustainability work, but it needs scientific research to secure that the actual environmental impacts of CE work toward sustainability.
Summary The so‐called circular economy—the concept of closing material loops to preserve products, parts, and materials in the industrial system and extract their maximum utility—has recently started gaining momentum. The idea of substituting lower‐impact secondary production for environmentally intensive primary production gives the circular economy a strong intuitive environmental appeal. However, proponents of the circular economy have tended to look at the world purely as an engineering system and have overlooked the economic part of the circular economy. Recent research has started to question the core of the circular economy—namely, whether closing material and product loops does, in fact, prevent primary production. In this article, we argue that circular economy activities can increase overall production, which can partially or fully offset their benefits. Because there is a strong parallel in this respect to energy efficiency rebound, we have termed this effect “circular economy rebound.” Circular economy rebound occurs when circular economy activities, which have lower per‐unit‐production impacts, also cause increased levels of production, reducing their benefit. We describe the mechanisms that cause circular economy rebound, which include the limited ability of secondary products to substitute for primary products, and price effects. We then offer some potential strategies for avoiding circular economy rebound. However, these strategies are unlikely to be attractive to for‐profit firms, so we caution that simply encouraging private firms to find profitable opportunities in the circular economy is likely to cause rebound and lower or eliminate the potential environmental benefits.
Rethinking economy requires rethinking the relationship between economics and its object. The economy is a recent product of socio-technical practice, including the practice of academic economics. Previously, the term “economy” referred to ways of managing resources and exercising power. In the mid-twentieth century, it became an object of power and knowledge. Rival metrological projects brought the economy into being. The development of the modern electricity industry illustrates the kind of work involved. It required new technical processes, new forms of distribution, addressing, and monitoring, new forms of calculation that were simultaneously electrical, chemical, economic, and social. Analyses of how the economic is embedded in social ties or in cultural meanings cannot understand these intersecting projects. The projects that form the economy involve the work of economics. Economic knowledge does not represent the economy from some place outside. It participates in making sites where its facts can survive. The case of an economic research project on property rights in Peru illustrates how this happens. Economic facts were established in a world that was organized, through specific projects, such as the property titling programs of Hernando de Soto, to enable economic knowledge to be made. There is no simple divide between a virtual world of economic theory and a real world outside it. Every economic project involves multiple arrangements of the simulated and that to which it refers.
Over the last decade, the concept of the circular economy has regained attention, especially related to efforts to achieve a more sustainable society. The ‘revival’ of the circular economy has been accompanied by controversies and confusions across different actors in science and practice. With this article we attempt at contributing to advanced clarity in the field and providing a heuristic that is useful in practice. Initially, we take a focus on the historical development of the concept of circular economy and value retention options (ROs) for products and materials aiming for increased circularity. We propose to distinguish three phases in the evolution of the circular economy and argue that the concept – in its dominant framing – is not as new as frequently claimed. Having established this background knowledge, we give insights into ‘how far we are’ globally, with respect to the implementation of circularity, arguing that high levels of circularity have already been reached in different parts of the globe with regard to longer loop value retention options, such as energy recovery and recycling. Subsequently, we show that the confusion surrounding the circular economy is more far reaching. We summarize the divergent perspectives on retention options and unite the most common views a 10R typology. From our analyses, we conclude that policymakers and businesses should focus their efforts on realization of the more desirable, shorter loop retention options, like remanufacturing, refurbishing and repurposing – yet with a view on feasibility and overall system effects. Scholars, on the other hand, should assist the parties contributing to an increased circular economy in practice by taking up a more active role in attaining consensus in conceptualizing the circular economy.