The related terms, sustainable and sustainability, have become popular and are used to describe a wide variety of activities which are generally ecologically laudable. At the same time, the term compromise is heard more frequently because the needs of the environment often are in conflict with the needs of humans. A brief examination of the question of compromise shows that a series of ten compromises, each of which saves 70% of the remaining environment, results in the saving of only 3% of the environment. Judging from the ways in which the terms sustainable and sustainability are used, their definitions are not very precise, especially when compromises are involved. An attempt is made here to give firm definition to these terms and to translate the definition into a series of laws and hypotheses which, it is hoped, will clarify the implications of their use. These are followed by a series of observations and predictions that relate to sustainability.

The pervasiveness of metaphor in environmental discourse suggests important questions about the role of metaphor in environmental learning. A conception of environmental thinking and action is proposed, which identifies five analytically distinct ‘moments’ of ‘environmental sensemaking’: conceptualising, knowing about, knowing how to respond, responding and acting. The (much-criticised) ‘information deficit’ model of environmental learning requires that the second moment—knowing about the environment—is the only locus of environmental learning. On the information deficit model the only role of metaphor is didactic. On the proposed conception, all five moments of environmental sense-making may be independent moments of environmental learning. Metaphor can have a rhetorical role (encouraging responsiveness) and, more importantly, conceptual metaphors can frame our understanding of the environment. The development of new metaphors plays a key role in environmental learning. The ‘natural capital’ and ‘real options’ metaphors are considered as ‘case studies’ of conceptual (or first-moment) learning. It is argued that while they may be important innovations in environmental sense-making, our general discussion of the role of metaphor in environmental learning suggests that we need to look beyond economic metaphors to improve our understanding of the environment–human relationship.

This paper describes some of the insights gained by the authors in the development of an approach for systemic sustainability analysis to arrive at sustainability indicators (SIs) for development. The paper describes the problems of perspective and mindset which such research involves, and the necessity to rethink both the purpose and content of SIs as well as taking into account the perspective of the researcher. The result represents a new perspective on the classification of SIs that serves to highlight one of the central difficulties encountered so far with these tools, namely their limited use in management and the setting of policy. We argue that this is due in large part to the nature of the SI frameworks created to date, even if carried out in a 'participative' mode. The framework itself is representative of a mindset or paradigm of understanding which, when applied as the sole device, we find less than adequate in achieving useful SIs. SIs arising from this mindset tend to be quantitative and explicit (clearly stated and with a defined methodology), while in practice most people's and institutions' use of SIs tends to be more qualitative and implicit ('understood' to apply in vaguer terms, with no defined methodology). These two paradigms or mindsets are represented here as the reductionist and the conversational : the first is characterised by quantitative and explicit indicators (or QNE* indicators); and the second is characterised by qualitative and implicit indicators (QLI* indicators). We suggest that what is required is far more research on the evolution and use of QLI* SIs (and the mindset which is necessary to develop them), in order to best appreciate how they can be hybridised with the QNE* group. The result may be termed 'multiple perspective' SIs.

"The first edition of Sustainability Indicators reviewed the development and value of sustainability indicators and discussed the advantage of taking a holistic and qualitative approach rather than focusing on strictly quantitative measures. In the new edition the authors bring the literature up to date and show that the basic requirement for a systemic approach is now well grounded in the evidence."--Jacket.

This monograph introduces green infrastructure as a strategic approach to land conservation that is critical to the success of smart growth initiatives. Green infrastructure is “smart” conservation that addresses the ecological and social impacts of sprawl and the accelerated consumption and fragmentation of open land. This monograph describes the concept and values of green infrastructure and presents seven principles and associated strategies for successful green infrastructure initiatives.

While our methods for measuring progress are better, our application of the indicators as a tool for social change still needs to improve. The are intended to be used by citizens and policymakers to guide behavior changes that will steer our community on a more sustainable course. The Indicators are a call to action—to spur critical thinking, to inspire us to reconsider our priorities, and to leverage actions that will ensure our community’s long-term health. It is time we do much more as individual citizens, business people, and policy makers to create a truly Sustainable Seattle. Achieving this goal is the most important legacy we can leave for future generations.

In this chapter we identify some of the indicators that have been proposed for assessing sustainability and suggest those that we believe are the most important ones to track. Then we propose how one could use these in assessing the state of the system, whether the system is becoming more or less sustainable, and how different programs can be evaluated that seek to make the system more sustainable. Before we move on, it is important to recognize two problems that will get in the way.

It should be apparent from this discussion that the definitions have moved from the academic realm to more practical constructs that can be implemented. There is considerable interest in using the concept of sustainable transport to help guide future policies and to evaluate activities and programs in measurable ways. We have identified many of the elements of a sustainable transport system, but let us see if we can go further and conceptualize something that is substantive enough to be measured.

This paper explores the use of metaphor in public policy and learning as a context for a reflective discussion of a nationally funded initiative focusing on the dissemination of good practice in education for sustainable development in the UK's post-16 sector. Learning to Last was the first, and so far only, project of its kind. Its conception and management epitomised the use of the toolkit metaphor, and reinforced and reproduced the instrumental rationality characterising educational governance and public management in the UK. The potential for metaphor or metaphorical concepts such as natural capital to articulate and stimulate new ways of thinking and behaving or even possibly offering a glimpse of a paradigmatic shift in institutional policy and practice relating to education and sustainability was not fully realised.

"This book examines how GIS applications can improve collaboration in decision making among those involved in promoting sustainable development. This volume reviews leading GIScience, providing an overview of research topics and applications that enable GIS newcomers and professionals to apply GIScience methods to sustainable spatial planning."--Jacket.

Green infrastructure’s value as a municipal or private investment depends in part on its effects beyond water management and thus upon a community’s ability to model and measure these additional values. Short of conducting an intensive study and calculation of actions in a specific community, municipalities have generally lacked the tools to determine green infrastructure’s multiple benefits. As such, defining or measuring the extent of green infrastructure’s multiple benefits has remained a challenge. While a number of cities have begun to explore GI within their own municipal infrastructure programs, no general method for estimating or documenting such benefits has yet emerged.

The services of ecological systems and the natural capital stocks that produce them are critical to the functioning of the Earth's life-support system. They contribute to human welfare, both directly and indirectly, and therefore represent part of the total economic value of the planet. We have estimated the current economic value of 17 ecosystem services for 16 biomes, based on published studies and a few original calculations. For the entire biosphere, the value (most of which is outside the market) is estimated to be in the range of US$16-54 trillion (1012) per year, with an average of US$33 trillion per year. Because of the nature of the uncertainties, this must be considered a minimum estimate. Global gross national product total is around US$18 trillion per year.

"In this chapter we explore the idea of environmental symmetry and its converse, environmental asymmetry. We start by defining what we mean by symmetry and demonstrating how symmetry concepts in a variety of guises have been widely applied in the biological and social sciences. We then consider the mechanisms that produce environmental asymmetry, the consequences of asymmetry, and the potential for interactions between different kinds of asymmetries in landscapes. We argue throughout that asymmetries are integral to self-organization in complex systems and are consequently of high importance for understanding complex system dynamics"

Suburban sprawl fans out from every major American city, and, in most places, it will continue to eat into fringe areas. At the same time, scattered low-density residential and commercial sprawl will consume bits and pieces of the outer-fringe countryside. Sprawl does not further the national goals of racial integration, energy efficiency, affordable housing, environmental quality, or economic competitiveness. Yet the federal government has given state and local governments little direction about how to control sprawl. Instead, federal tax policies, regulations, and spending programs have been powerful contributors to sprawl.

Green Infrastructure (GI) is what might be termed a developing concept. It might also be defined a contested concept i.e. it means different things to different people. It is for this reason that any project to move forward on GI planning needs to ensure that the key interest and stakeholder groups are effectively engaged with the project and that their differing priorities and appreciations of GI as a concept and as environments on the ground are accounted for. This project was primarily exploratory to try to understand the concept and contribute to discussion with regard to methodologies by which the practice of GI planning can be developed.

At the dawn of the 21st century, a new revolution is gaining strength - the Sustainability Revolution. The purpose of this work is to help those inside this revolution, as well as those presently outside, better understand where sustainability is coming from and where it might be going. (first paragraph)

If the most powerful growth engine driving America’s economy is run by psychopaths, America’s in deep trouble. We must ask: Is the Big Oil cartel acting in the best interests of America or merely in the short-term interests of shareholders and insiders like Tillerson, who makes $40 million a year? And are they killing our future?

This paper sketches the fundamental characteristics of metaphorical language which enable it to subserve not only the shaping of particular discourses, but also crucial aspects of our powers of enquiry and understanding. It argues that without metaphorical creativity we cannot make adequate sense of the more complex and open-ended aspects of our experience. This is illustrated from the way in which we deploy the closely related key environmental metaphors of ‘stewardship’ and ‘natural capital’, including the more specific ‘real option’ sub-version of the latter idea reported on by other contributions to this Special Issue. But a condition of making such thinking operational and socially productive is the development of a genuine learning society.

This paper examines the implications for sustainability policy of environmental uncertainty and indeterminacy, and relates the associated problems with a conventional understanding of sustainable development to Hayek's critique of collective planning. It suggests that the appropriate recourse is not, however, a Hayekian endorsement of the free market, but an extension of his key idea of spontaneous order to characterise the learning society. The argument is illustrated by a practical application: the analysis of natural capital explored in this Special Issue is shown to be directly relevant to the improvement of the UK's headline sustainability indicators package.

One way in which the concept of sustainable development has been understood is through the metaphor of natural capital. This sees that the natural world has performing functions similar to those of economic capital. This metaphor is usually developed by applying to Nature standard economic techniques for capital valuation. However, where valuation of economic capital is complex, additional techniques are often used. One such technique is 'real options' analysis. Applying this technique to the concept of natural capital tends to lead to its revaluation, and has particular implications for the role of learning. Learning opportunities arising from the real options metaphor are explored through a number of examples.

The chapter addresses sustainable development as a theoretical concept rather than a political ideal (see Chapter 1). Eowever, it takes both a descriptive approach, by assessing the sustainability of development in the real world in relation to an ideal sustainable path, and a prescriptive approach, by examining the various strategies which are, or could be, used to make development more sustainable. A key broad underlying question is whether existing theories, largely conceived from an aspatial perspective, have limitations when applied spatially.

This note puts the research project which led to this Special Issue in the context of developments in and around environmental policy over the past two decades, from the perspective of someone closely involved. It links political and institutional problems over sustainable development to the changing role and authority of science in contemporary society, and to the new kind of emphasis on social learning to be found in the papers that follow.

This chapter will present an overview of the potential uses of census data, provide examples of the use of census data in particular countries and highlight the potential of such data to provide evidence in still unexplored areas. It aims to call attention to the need to act now in order to better position environmental statistics in censuses, through the inclusion of questions and the development of methods for processing and analysing geo-referencing population data. The potential of population and housing censuses is indisputable. However, their use will largely be affected by the availability of the data, the degree of their dissemination, the extent of the analysis based on the information collected, the quality of the data and, most important, the relevance that is given to the census data as key inputs for policy design. In the particular case of environmental analysis, in addition to the areas mentioned above, use of the data will depend on the availability of geo-referenced maps as well as on having census enumeration areas that are small enough to allow for linking population data to environmental-geographic data.

This book broadens and deepens understanding of a wide range of population-climate change linkages. Combining climate change and Incorporating population dynamics into research, policymaking and advocacy is critical for understanding the trajectory of global greenhouse gas emissions, for developing and implementing adaptation plans and thus for global and national efforts to curtail this threat. Substantial resources are being dedicated to research and policy efforts to mitigate climate change and support adaptation to the current and future impacts of greenhouse gas emissions. Yet the lack of consideration of population dynamics hampers the development of stronger, more effective solutions to the challenges climate change poses. The papers in this volume provide a substantive and methodological guide to the current state of knowledge on issues such as population growth and size and emissions; population vulnerability and adaptation linked to health, gender disparities and children; migration and urbanization; and the data and analytical needs for the next stages of policy-relevant research.

Tools that support public engagement with sustainability are essential for local sustainability planning. This research investigates the ability of two geographic information system (GIS)-based tools to promote discussion of sustainability in a suburban context. A local ecological footprint tool and a community environmental atlas (an environmentally themed online mapping system) were created for seven suburban boroughs of Montreal. Variations of both tools have been used to support sustainability efforts, but their use has not been widely evaluated. Working from a public participation GIS (PPGIS) framework that recognizes the powerful influence of data representation, this research uses focus groups to evaluate how well these tools address three criteria that have emerged from the literature on public engagement in sustainability: interdependency across systems, reflexivity about personal and social decision making, and interactions across spatial scales. Whereas the atlas remains advantageous for discussing local spatial specifics, it was found that the ecological footprint helped people see the interconnections among systems, integrate local and global aspects of sustainability, and reflect on the values and assumptions underlying current social and economic structures.

Ecosystem services have been researched and promoted widely as a tool to address biodiversity conservation and as an approach to tackle climate change mitigation/adaptation. This paper explores the potential for delivering ecosystem services through spatial planning, proposing an ecological turn in planning theory and practice. Specifically, we examine the emerging literature surrounding green infrastructure to: (1) identify ecological principles to inform planning policies and processes; (2) propose a re-scoping of spatial planning practices to place ecology, ecosystem services and environmental risks as central concerns of planning practice; and (3) examine effective procedures to ensure more ecologically sound outcomes in the planning process.

This report provides guidance on the use of indicators for sustainable and livable transportation planning. It defines sustainability and livability, discusses sustainable development and sustainable transport concepts, and how sustainability indicators can be applied in transport evaluation and planning. It describes factors to consider when selecting sustainable transportation indicators, identifies examples of indicators and indicator sets, and provides recommendations for selecting sustainable transport indicators for use in a particular situation.

This book is the work ofa skeptical environmentalist. Environmentalist, because I - like most others - care for our Earth and care for the future health and wellbeing ofits succeeding generations. Skeptical, because I care enough to want us not just to act on the myths of both optimists and pessimists. Instead, we need to use the best available information to join others in the common goal of making a better tomorrow.

McKibben's earliest warnings about global warming went largely unheeded. In this book, he argues that we can meet the challenges of a new "Eaarth"--Still recognizable but suddenly and violently out of balance--by building the kind of societies and economies that can hunker down, concentrate on essentials, and create the type of community that will allow us to weather trouble on an unprecedented scale.

The main objective of this paper is to outline a tentative agenda for building disaggregated models that infer urban land use distributions and therefore can be used to inform classified imagery of urban areas. The disaggregated models are based on digital postal records of every delivery address in a city; both residential and commercial properties (Figure 1). Knowing the spatial distribution of postal addresses introduces a number of key indicators of density (compactness versus sparseness) and arrangement (linearity versus randomness). These are measured using standard and linear readjusted nearest neighbor statistics. By establishing a relationship between image pixels and building distributions, the long-term research goal is to facilitate reliable and accurate spatial pattern recognition and multispectral classification methodologies to a level that renders resulting output irresistible to planners and policy makers (Donnay, 1999). Such work may even deflect criticism and restore flagging confidence in the applicability of urban remote sensing in the developed world (Mesev, 2003).

Ecovillages, co-housing communities, and other types of intentional communities (ICs) have proliferated in recent years. There are currently several thousands of these communities worldwide and their numbers are increasing rapidly. We surveyed a subset of these communities to learn more about their characteristics, including their world view or vision, the status of four basic types of capital (built, human, social, and natural), and the quality of life (QoL) they provide for their residents. Survey results indicate that ICs have a better balance between built, human, social, and natural capital than unintentional communities (based on a parallel survey of neighborhoods in Burlington, VT, USA) and that this results in a higher QoL among residents. It is difficult to assess the sustainability of ICs, but the data indicates that within ICs, social capital is substituted for built capital thereby reducing the level of material throughput.

Recovery of the Puget Sound is more than a scientific and technological endeavor. Sustainable solutions require attention to human factors that contributed to the current situation and that may slow or accelerate efforts to achieve a balanced and healthy ecosystem. Various behaviors, structures, processes, and practices in local governments, for example, may impede the implementation of the Puget Sound Action Agenda. Developed by the Puget Sound Partnership, a Washington state agency charged with coordinating Puget Sound recovery efforts, the Action Agenda sets priorities for Puget Sound recovery at local and regional levels. This rapid ethnographic assessment uses a literature review, participant observation, interviews, focus groups, mapping exercises, public document analysis, and an online survey to reveal an insider’s view of barriers within municipal governments to the implementation of Action Agenda priorities related to green infrastructure in the twelve county Puget Sound region in Washington State.

This chapter argues that a meaningful concept of equity has not, in fact, been seriously integrated into most sustainable development scholarship and practice. Constantly bandied about, but rarely defined or made operational, equity is at best a subsidiary concern in the sustainable development discourse and at worst a politically correct totem to be bowed to when advancing the main agenda. Different ideas of simple economic equity have, by and large, been embroidered onto the broader economic growth/environmental sustainability tapestry.

This Handbook is a guide for constructing and using composite indicators for policy makers, academics, the media and other interested parties. While there are several types of composite indicators, this Handbook is concerned with those which compare and rank country performance in areas such as industrial competitiveness, sustainable development, globalization and innovation. The Handbook aims to contribute to a better understanding of the complexity of composite indicators and to an improvement of the techniques currently used to build them. In particular, it contains a set of technical guidelines that can help constructors of composite indicators to improve the quality of their outputs.It has been prepared jointly by the OECD (the Statistics Directorate and the Directorate for Science, Technology and Industry) and the Applied Statistics and Econometrics Unit of the Joint Research Centre (JRC) of the European Commission in Ispra, Italy.

Urban sprawl has become the catch phrase for everything that is bad about urban growth today--congestion, blight, monotony, endless development, and ecological destruction. Beneath the hoopla, however, is a serious debate about how to manage urban growth effectively. This paper provides a framework for decomposing sprawl into its component parts. The paper's objective is to distinguish those aspects associated with sprawl that are truly bad from those that are not. It identifies fourteen outcomes that are associated with or blamed on sprawl, and then discusses which ones are truly deleterious and which ones are not. The paper concludes that sprawl is a complex, multi-faceted problem requiring multi-faceted solutions.

The chapter begins by comparing geography's long-standing interest in both society and nature, and the links that unite them, with the new agenda of sustainable development. This is followed by a brief review of the attention given to sustainable development in the geographical literature, and to the themes of place and space in discussions of sustainable development. The chapter then moves on to consider the potential for applying geographical skills in planning for more sustainable develop- ment. Arguably more important, however, is a greater geographical contribution to critical reviews of current thinking about sustainable development, both in practice and in theory.

Four Steps to an Ecology of the Economy: Map, List, Incentives, People Economics and politics are actually one seamless continuum - the engine of productivity together with the rules of its functioning, including who benefits and who pays. Those rules are called natural laws and human policies. This whole system is made up of plants and animals recycling and rearranging the raw elements of solar and mineral wealth, eating one another and evolving on behalf of each individual, each species, and all of life. As if this weren't complicated enough, human beings work on behalf of families, religions, ethnic groups, professions, cities, nations, alliances of nations, and the United Nations as well as self, species, and the one and all of life in the universe. We seem to be so diverse in our deeper selves that each of us works for a different mix of those constituencies, some times forgetting one or more altogether. Yet we are always building that edifice that supports us all, our civilization, which is made up ofall our cities and physical systems functioning according to rules we made up ourselves, based in turn on the rules of nature. Given the order, with the human edifice built upon the natural one, it is clear that ifour rules differ markedly from nature's, we are likely to run into problems.

Tools suited to the taks of reshaping cities for a far healthier future than the one we are fabricating now - greenbelt laws, for example - have existed for a long time and will remain important far into the future. Some of them, such as the transfer ofdevelopment rights (TDR), are being used effectively in many places but should be used much more widely and may require redesigning to work better and replicate themselves more quickly. In addition, completely new tools need to be designed to fill out a whole toolbox for ecocities. One of my own inventions, building on Ian McHarg's mapping system in Design with Nature, is the e~ocity zoningoverlay map. There are many more. When Jaime Lerner told the people of Curitiba that environmentally healthy policies and practices were important and that they, the people, were important, he helped create a culture of acceptance and support for very substantial urban transformations from the foundation in land uses on up. Given a culture ofsupport in which people take problems and solurions of the sort addressed in this book seriously, these tools can be used to change the world profoundly. Some of them, in fact, can be used effectively by a small number of people right away, and this can build momentum toward more general public support. Then healthy cities and a vital biosphere become possible.

Introduces articles related to environmental education, published in the February 2005 issue of the journal "Environmental Education Research."

Moving toward sustainable communities is a long-term goal, so it is important that the incremental steps we take in the short-term are leading us in the right direction. This chapter surveys some of the many tools available to citizens and their governments for managing community sustainability, and then discusses one of these tools, sustainability indicators, in more detail.

What is a sustainable community? The concept does not describe just one type of neighborhood, town, city or region. Activities that the environment can sustain and that citizens want and can afford may b~ quite different from community to community. Rather than being a fixed thing, a sustainable community is continually adjusting to meet the social and economic needs of its residents while preserving the environment's ability to support it. This chapter examines sustainability at the community level. It begins with a look at communities in developed and developing parts of the world, proceeds to investigate some of the reasons why our North American communities are presently unsustainable, explores some characteristics and images of more sustainable communities, and concludes with the role of citizens and their governments in moving us toward sustainable communities.

Unsustainable transport systems not only are a major contributor to atmosphere change, but also lead to increasing congestion, longer commuting times, increasing demands for shorter work hours to compensate for longer travel hours, and higher prices due to reduced worker productivity. In fact, the primary objective of conventional traffic management has been to move vehicles in and around communities as rapidly and efficiently as possible using strategies such as designation of one way streets, synchronization of traffic signals, road widening, and construction ofleft-hand turn bays.

Assessing and mapping neighborhood quality has a long legacy toward enhancing the vitality and quality of life in cities in the United States. This study utilized factor analysis and GIS-weighted overlay techniques for assessing neighborhood quality in Milwaukee, Wisconsin. The study integrates several objective neighborhood parameters that address important neighborhood tenets. First, a data-reduction tool was invoked to reduce a large number of variables into several comprehensive indicators that relate to established socioeconomic and contextual paradigms. These factors then were ranked and aggregated using GIS overlay techniques to produce a map depicting neighborhood integrity. The approach shown here demonstrates how several types of administrative datasets can easily be utilized in a GIS-based modeling environment to reach neighborhood quality indices. The results show promise for persons involved in neighborhood planning or defining neighborhoods where objectivity and often multiple competing criteria are present.

Today most of these schools and thousands of other campuses are surrounded by urban development. In some cases such as the University of Chicago, Carnegie Mellon, the Massachusetts Institute ofTechnology, San Jose State University, Wayne State University, or Georgetown University-not only has there been an "engulfment" of urbanization but also there have been substantial increases of population density in close proximity to the typical urban campus. These two forces, the urban swallowing of the campus and the densification of the contiguous neighborhoods, set the stage for land-use problems. Many school administrators believe the institution needs to grow in order to survive or stay competitive with other schools while the town struggles with added housing demands and traffic congestion and overspill into the community (Gurwitt 2003).

All of these questions relate to resilience, the ability of a system to absorb disturbance and still retain its basic function and structure. They also relate to concepts of sustainability and the challenge of servicing current system demands without eroding the potential to meet future needs. We live in a time of growing population coupled with a declining resource base and great uncertainty about a range of environmental issues such as climate change. How can we make the systems that we depend upon resilient? But before we address issues of resilience, stop and consider for a moment our current practices of resource management.

Because of the geographical nature of the application, most users of geodemographics recognize the need for the investment in some form of information system for manipulating the geographical information they hold regarding the home locations of their customers, the postal, administrative, media, and sales geographies used in their business, and the locational information they hold about their outlets and those of their competitors. However, many geographers have found it more difficult to recognize the differences between conventional GIS and geodemographic information systems than their similarities. This has often led to a failure to recognize the bespoke investments that are needed in software solutions as well as in data and visualization tools in order to sustain effective returns from this form of analysis.

In this chapter we examine static attributes of landscapes which may be used both as indicators of landscape processes (dynamics) and of likely response to human action. For example, a soil type may indicate both vulnerability to the erosion process and suitability for agriculture development. We also consider how such landscape characteristic can be mapped, using field and remotely sensed data, computerized data storage and retrieval, and graphical presentation. Finally, we examine how the predicted landscape alterations from development proposals. can be evaluated using economic, ecological, or aesthetic criteria.

This paper views the concept of natural capital from an economist's perspective. It begins by drawing on historical debates in economics on the nature of capital. These serve to identify central issues to do with the relationship between theory, empirics and method in the way in which the concept of capital is deployed in economic discourse. It is suggested that these have resonance for current discussions of the concept of natural capital. Against this background, the paper then discusses the way in which natural capital figures in the analysis of sustainability, and pinpoints various incoherencies. Finally, it draws on recent analyses of technical innovation as a possible solution to the problem of sustainability. It is suggested that there may be a conflict between narrow path-dependent solutions to the alleged problem, and more open learning-based approaches. The latter are exemplified by building on and reinterpreting the environmental economist's concept of a quasi-option.