This book is the result of collaborations by a network of researchers across Europe and beyond. As a group, we share the conviction that sustainability science needs public participation to be successful. We also think that in order to really work, such public participation requires not only an open mind on all sides, but also improved tools. How did we reach this conviction?

Sustainability is an elusive concept. One of the few things that can be said with certainty is that sustainable (as well as unsustainable) development depends on an intricate web of interactions in linked systems, both natural and social. This web cannot be steered by any simple action into a premeditated direction. There is no easy way to open this Gordian knot, and trying to do so with the proverbial sword would damage rather than enhance our chances of a sustainable future.

This situation implies two things. First, sustainability cannot be approached by a grand master plan with a precise mapping of the end point and the trajectory to get there. Rather, it is ‘our common journey’ as humankind; it consists of one tentative step after the other, with the need for continuous feedback about whether we are going roughly in the right direction or not (National Research Council 1999). Given the complex systems involved, there is not much hope of achieving such meaningful feedback without using the potential of modern information technology, especially computer modeling.

This book reports the results of a grand experiment in how lay publics might be more effectively engaged in linking science and technology to the quest for sustainable development.

The experiment integrates three long-established but usually isolated lines of thought. The first concerns the appropriate role of science and technology in a transition toward sustainability. Early thinking on sustainability – such as that articulated in the World Conservation Strategy of 1980 – relied heavily on scientific studies of renewable resource management, carrying capacities, and environmental limits. The Brundtland Commission's 1987 report “Our Common Future” properly stressed the importance for any sustainable development strategy of targeted investments in knowledge creation and application. Over the subsequent decade, however, such investments generally lagged far behind needs. It has only been in the context of discussions surrounding the 2002 World Summit on Sustainable Development that widespread attention has begun to return to securing the scientific and technological foundations for a transition toward sustainability. One of the exceptions to this general trend has been in the relatively well-supported problem of climate change addressed in the study reported here. Climate change is, of course, only one aspect of the overall sustainability challenge. It none the less incorporates many of the most formidable elements of that challenge: tight coupling between social and environmental systems across multiple spatial scales; complexity in the resulting interactions that makes counterintuitive surprise the norm; and sufficiently long time lags between interventions and consequences to make wait-and-see management an option only for ostriches.

Sometimes I am astonished when taking a “sustainability” look at energy relevant news. The continued operation of smaller hydroelectric power plants, which are producing electricity with extremely low life-cycle carbon dioxide emissions, is questioned due to the availability of cheap electricity from fossil fuels. Heat insulation of buildings is progressing, yet the energy management of new buildings is considered clearly less important than aesthetic design and other factors. Small, light-weight fuel efficient vehicles are available on the market, yet the trend of current sales favors heavier and ever more powerful cars. Energy efficient appliances stay on the shelf as less efficient devices are offered at lower prices.

These facts show that ecologically favorable technical solutions are presently not being chosen, as sustainability arguments are not ranked high within the set of preferences of public and individual actors. This is why Public Participation in Sustainability Science, the subject of this book, is of utmost importance. Unless we succeed in engaging those stakeholders who ultimately decide on energy relevant investments and purchases better in sustainability debates, the market penetration of energy efficient or ecologically benign technology will be impeded or severely delayed. Such delays could have far-reaching consequences for our planet. Hence, it is necessary that not only Sustainability Policy but also Sustainability Science starts to involve the public in its discussions.

The approach of Integrated Assessment Focus Groups presented in this book combines two important aspects.

While the first two parts of this volume have focused on the IA Focus Group approach to public participation in sustainability science, the third part relates this research to further forms of participation explored in recent projects and programs. It starts from one of the central findings of the focus group work discussed earlier, namely that citizens throughout Europe tend to be in favor of climate change mitigation by reducing overall energy use in the future. In Chapter 7, Kasemir et al. discuss a participatory exercise with representatives from venture capital and young technology companies and from the European Commission, that explored options of how to initiate significant reductions of fossil fuel use by early-stage investments into ecologically sound energy innovation. The participants considered changes in tax exemptions, subsidies and government guarantee schemes to be at least as important as carbon taxes. Taking a long-term perspective, Tuinstra et al. then describe in Chapter 8 how the Dutch COOL project studied options for drastic (50–80 per cent) reduction of carbon dioxide emissions in the long run. Central to this project were participatory processes at three different scales: the Dutch national context, the European, and the global scale. Common lessons from the research discussed in the earlier parts of this volume and from the COOL project are discussed. In Chapter 9 Downing et al. then change the focus of the discussion from climate change mitigation to regional adaptation.

This final part of the present volume looks at the research described in the earlier parts, especially the work on IA Focus Group procedures, from a bird's-eye perspective, and explores its meaning for the future development of integrated assessment and sustainability science. In Chapter 11, van Asselt and Rotmans discuss the role of this research for the development of a broader research program of integrated assessment. As an example, they describe how this research has helped them build a bridge between earlier work on integrated modeling and uncertainty, and more recent research on “integrated visions for a sustainable Europe” that combines stakeholder participation with modeling work. While their work, like the bulk of the research on public participation in sustainability science discussed in this volume, has been conducted in Europe, in Chapter 12 Ramakrishna discusses what role citizens of developing countries can play in sustainability debates. He explores similarities and differences between the research discussed throughout this volume and experiences in the developing world, and from this draws conclusions on how increasing public participation could support understanding and collective action toward sustainability, particularly in developing countries. Finally, in the concluding Chapter 13, Stoll-Kleemann, O'Riordan and Burns assess the general potential of increasing the role of citizens in shaping a sustainable future. They argue that interactive, multilevel governance is essential in tackling the sustainability challenge, and that the experiences discussed in this book can help us understand how this might be achieved.

This first part summarizes underlying concepts and major insights of the research on public participation in sustainability science discussed in this book. In Chapter 1, Kasemir et al. argue that currently decision-making on sustainability issues in general, and climate policy in particular, is in a transition from taking first careful steps of analysis to preparing major shifts in socio-economic activities. This transition needs an improved integration of citizens' and stakeholders' views into policy making to be successful. Documented and tested participatory procedures, which integrate expert knowledge with views held by the public, are necessary. The IA Focus Group methodology, developed to address this need, is discussed, and major results concerning citizen views on climate change and energy use are summarized. In Chapter 2, Gough et al. then focus specifically on conditions for meaningful participation in such procedures. Their findings include that open-ended settings, in which both participants and moderation team steer the process together, may initially even increase scepticism, but in the longer run support the establishment of mutual trust and understanding. Also, the medium of interaction between lay publics and expertise in participatory procedures was found to be crucial. In most IA Focus Groups conducted in the research discussed in this book, computer models were an essential medium of this interaction. In Chapter 3, Jerry Ravetz suggests that such integrated models on global change issues face such high uncertainties that they can be understood to have a metaphorical rather than a predictive function.

The second part of this book concerns procedures for citizen participation in sustainability science, and results obtained from such participatory procedures. As in Part I on Concepts and Insights, also in the research discussed in Part II, the issue of climate change and its relation to urban lifestyles is used as a case study to examine the possible roles of public participation in sustainability science. In order to allow a meaningful interaction between lay and expert perspectives in participatory procedures on this issue, these IA Focus Groups with citizens consisted of three distinct phases. Experiences with collage processes in the first phase of IA Focus Groups, allowing participants to express their spontaneous feelings on the focal topic of climate change and energy use, are discussed in Chapter 4 by Kasemir et al., and illustrated with examples of collage pictures. Findings include the fact that citizens across Europe saw a future with strongly reduced energy use rather positively, more so than might be found, for example, in a US context. In making collages, the citizens were found to be rather sophisticated in dealing with ambiguity and uncertainty. In Chapter 5, Dahinden et al. discuss the use of computer models in the second phase of IA Focus Group procedures. These models were found to be powerful tools for promoting insights about complex sustainability issues like climate change, but future models could be improved, in particular with regard to accessibility to lay audiences.