The Guardian’s Political Science blog post by Alice Bell about the Memorandum of Understanding between the UK Natural Environment Research Council and Shell, reminded me of a nagging issue that has concerned me for a while: to what degree GIS contributed to anthropocentric climate change? and more importantly, what should GIS professionals do?
I’ll say from the start that the reason it concerns me is that I don’t have easy answers to these questions, especially not to the second one. While I personally would like to live in a society that moves very rapidly to renewable energy resources, I also take flights, drive to the supermarket and benefit from the use of fossil fuels – so I’m in the Hypocrites in The Air position, as Kevin Anderson defined it. At the same time, I feel that I do have responsibility as someone who teaches future generations of GIS professionals how they should use the tools and methods of GIScience responsibly. The easy way would be to tell myself that since, for the past 20 years, I’ve been working on ‘environmental applications’ of GIS, I’m on the ‘good’ side as far as sustainability is concerned. After all, the origins of the biggest player in our industry are environmental (environmental systems research, even!), we talk regularly about ‘Design With Nature’ as a core text that led to the overlays concept in GIS, and we praise the foresight of the designers of the UNEP Global Resource Information Database in the early 1980s. Even better, Google Earth brings Climate Change information and education to anyone who want to downloaded the information from the Met Office.
But technologies are not value-free, and do encapsulate certain values in them. That’s what critical cartography and critical GIS has highlighted since the late 1990s. Nadine Schuurman’s review is still a great starting point to this literature, but most of it analysed the link of the history of cartography and GIS to military applications, or, in the case of the volume ‘Ground Truth’, the use of GIS in marketing and classification of people. To the best of my knowledge, Critical GIScience has not focused its sight on oil exploration and extraction. Of course, issues such as pollution, environmental justice or environmental impacts of oil pipes are explored, but do we need to take a closer look at the way that GIS technology was shaped by the needs of the oil industry? For example, we use, without a second thought, the EPSG (European Petroleum Survey Group) definitions of co-ordinates reference systems in many tools. There are histories of products that are used widely, such as Oracle Spatial, where some features were developed specifically for the oil & gas industry. There are secretive and proprietary projections and datums, and GIS products that are unique to this industry. One of the most common spatial analysis methods, Kriging, was developed for the extractive industry. I’m sure that there is much more to explore.
So, what is the problem with that, you would say?
Fossil fuels – oil, coal, gas – are at the centre of the process that lead to climate change. Another important thing about them is that once they’ve been extracted, they are likely to be used. That’s why there are calls to leave them in the ground. When you look at the way explorations and production work, such as the image here from ‘Well Architect‘, you realise that geographical technologies are critical to the abilities to find and extract oil and gas. They must have played a role in the abilities of the industry to identify, drill and extract in places that were not feasible few decades ago. I remember my own amazement at the first time that I saw the complexity of the information that is being used and the routes that wells take underground, such as what is shown in the image (I’ll add that this was during an MSc project sponsored by Shell). In another project (sponsored by BP), it was just as fascinating to see how paleogeography is used for oil exploration. Therefore, within the complex process of finding and extracting fossil fuels, which involves many engineering aspects, geographical technologies do have an important role, but how important? Should Critical GIScientists or the emerging Critical Physical Geographers explore it?
This brings about the more thorny issue of the role of GIS professionals today and more so with people who are entering the field, such as the students who are studying for an MSc in GIS, and similar programmes. If we accept that most of the fossil fuels should stay underground and not be extracted, than what should we say to students? If the person that involved in working to help increasing oil production does not accept the science of climate change, or doesn’t accept that there is an imperative to leave fossil fuels in the ground, I may accept and respect their personal view. After all, as Mike Hulme noted, the political discussion is more important now than the science and we can disagree about it. On the other hand, we can take the point of view that we should deal with climate change urgently and go on the path towards reducing extraction rapidly. In terms of action, we see students joining campaigns for fossil free universities, with which I do have sympathy. However, we’re hitting another difficult point. We need to consider the personal cost of higher education and the opportunity for well paid jobs, which include tackling interesting and challenging problems. With the closure of many other jobs in GIS, what is the right thing to do?
I don’t have an easy answer, nor can I say that categorically I will never work with the extractive sector. But when I was asked recently to provide a reference letter by a student in the oil and gas industry, I felt obliged to state that ‘I can completely understand why you have chosen this career, I just hope that you won’t regret it when you talk with your grandchildren one day in the future’
5 December, 2012
Recently, I attended a meeting with people from a community that is concerned with vibration and noise caused by a railway near their homes. We have discussed the potential of using citizen science to measure the vibrations that pass the sensory threshold and that people classify as unpleasant, together with other perceptions and feeling about these incidents. This can form the evidence to a discussion with the responsible authorities to see what can be done.
As a citizen science activity, this is not dissimilar from the work carried out around Heathrow to measure the level of noise nuisance or air pollution monitoring that ExCiteS and Mapping for Change carried out in other communities.
In the meetings, the participants felt that they need to emphasise that they are not against the use of the railway or the development of new railway links. Like other groups that I have net in the past, they felt that it is important to emphasise that their concern is not only about their locality – in other words, this is not a case of ‘Not In My Back Yard’ (NIMBY) which is the most common dismissal of local concerns. The concern over NIMBY and citizen science is obvious one, and frequently come up in questions about the value and validity of data collected through this type of citizen science.
During my masters studies, I was introduced to Maarten Wolsink (1994) analysis of NIMBY as a compulsory reading in one of the courses. It is one of the papers that I keep referring to from time to time, especially when complaints about participatory work and NIMBY come up.
Inherently, what Wolsink is demonstrating is that the conceptualisation of the people who are involved in the process as selfish and focusing on only their own area is wrong. Through the engagement with environmental and community concerns, people will explore issues at wider scales and many time will argue for ‘Not in Anyone’s Back Yard’ or for a balance between the needs of infrastructure development and their own quality of life. Studies on environmental justice also demonstrated that what the people who are involved in such activities ask for are not narrow, but many times mix aspects of need for recognition, expectations of respect, arguments of justice, and participation in decision-making (Schlosberg 2007).
In other words, the citizen science and systematic data collection are a way for the community to bring to the table evidence that can enhance arguments beyond NIMBY, and while it might be part of the story it is not the whole story.
For me, these interpretations are part of the reason that such ‘activism’-based citizen science should receive the same attention and respect as any other data collection, most notably by the authorities.
Wolsink, M. (1994) Entanglement of Interests and Motives: Assumptions Behind the NIMBY-Theory on Facility Siting, Urban Studies, 31(6), pp. 851-866.
Scholsberg, D. (2007) Defining Environmental Justice: Theories, Movements, and Nature. Oxford University Press, 2007
19 December, 2011
As noted in the previous post, which focused on the linkage between GIS and Environmental Information Systems, the Eye on Earth Summit took place in Abu Dhabi on the 12 to 15 December 2011, and focused on ‘the crucial importance of environmental and societal information and networking to decision-making’. Throughout the summit, two aspects of public were discussed extensively. On the one hand, Principle 10 of the Rio declaration from 1992 which call for public access to information, participation in decision making and access to justice was frequently mentioned including the need to continue and extend its implementation across the world. On the other, the growing importance of citizen science and crowdsourced environmental information was highlighted as a way to engage the wider public in environmental issues and contribute to the monitoring and understanding of the environment. They were not presented or discussed as mutually exclusive approaches to public involvement in environmental decision making, and yet, they do not fit together without a snag – so it is worth minding the gap.
As I have noted in several talks over the past 3 years (e.g. at the Oxford Transport Research Unit from which the slides above were taken), it is now possible to define 3 eras of public access to environmental information. During the first era, between the first UN environmental conference, held in Stockholm in 1972, were the UN Environmental Programme (UNEP) was established, and the Earth conference in Rio in 1992, environmental information was collected by experts, to be analysed by experts, and to be accessed by experts. The public was expected to accept the authoritative conclusions of the experts. The second period, between 1990s and until the mid 2000s and the emergence of Web 2.0, the focus turned to the provision of access to the information that was collected and processed by experts. This is top-down delivery of information that is at the centre of Principle 10:
‘Environmental issues are best handled with participation of all concerned citizens, at the relevant level. At the national level, each individual shall have appropriate access to information concerning the environment that is held by public authorities, including information on hazardous materials and activities in their communities, and the opportunity to participate in decision-making processes. States shall facilitate and encourage public awareness and participation by making information widely available. Effective access to judicial and administrative proceedings, including redress and remedy, shall be provided’
Notice the two emphasised sections which focus on passive provision of information to the public – there is no expectation that the public will be involved in creating it.
With the growth of the interactive web (or Web 2.0), and the increase awareness to citizen or community science , new modes of data collection started to emerge, in which the information is being produced by the public. Air pollution monitoring, noise samples or traffic surveys – all been carried out independently by communities using available cheap sensors or in collaboration with scientists and experts. This is a third era of access to environmental information: produced by experts and the public, to be used by both.
Thus, we can identify 3 eras of access to environmental information: authoritative (1970s-1990s), top-down (1990s-2005) and collaborative (2005 onward).
The collaborative era presents new challenges. As in previous periods, the information needs to be at the required standards, reliable and valid. This can be challenging for citizen science information. It also need to be analysed, and many communities don’t have access to the required expertise (see my presentation from the Open Knowledge Foundation Conference in 2008 that deals with this issue). Merging information from citizen science studies with official information is challenging. These and other issues must be explored, and – as shown above – the language of Principle 10 might need revision to account for this new era of environmental information.
17 December, 2011
The Eye on Earth Summit took place in Abu Dhabi on the 12 to 15 December 2011, and focused on ‘the crucial importance of environmental and societal information and networking to decision-making’. The summit was an opportunity to evaluate the development of Principle 10 from Rio declaration in 1992 as well as Chapter 40 of Agenda 21 both of which focus on environmental information and decision making. The summit’s many speakers gave inspirational talks – with an impressive list including Jane Goodall highlighting the importance of information for education; Mathis Wackernagel updating on the developments in Ecological Footprint; Rob Swan on the importance of Antarctica; Sylvia Earle on how we should protect the oceans; Mark Plotkin, Rebecca Moore and Chief Almir Surui on indigenous mapping in the Amazon and man others. The white papers that accompany the summit can be found in the Working Groups section of the website, and are very helpful updates on the development of environmental information issues over the past 20 years and emerging issues.
Interestingly, Working Group 2 on Content and User Needs is mentioning the conceptual framework of Environmental Information Systems (EIS) which I started developing in 1999 and after discussing it in the GIS and Environmental Modelling conference in 2000, I have published it as the paper ‘Public access to environmental information: past, present and future’ in the journal Computers, Environment and Urban Systems in 2003.
Discussing environmental information for a week made me to revisit the framework and review the changes that occurred over the past decade.
First, I’ll present the conceptual framework, which is based on 6 assertions. The framework was developed on the basis of a lengthy review in early 1999 of the available information on environmental information systems (the review was published as CASA working paper 7). While synthesising all the information that I have found, some underlying assumptions started to emerge, and by articulating them and putting them together and showing how they were linked, I could make more sense of the information that I found. This helped in answering questions such as ‘Why do environmental information systems receive so much attention from policy makers?’ and ‘Why are GIS appearing in so many environmental information systems ?’. I have used the word ‘assertions’ as the underlying principles seem to be universally accepted and taken for granted. This is especially true for the 3 core assumptions (assertions 1-3 below).
- Sound knowledge, reliable information and accurate data are vital for good environmental decision making.
- Within the framework of sustainable development, all stakeholders should take part in the decision making processes. A direct result of this is a call for improved public participation in environmental decision making.
- Environmental information is exceptionally well suited to GIS (and vice versa). GIS development is closely related to developments in environmental research, and GIS output is considered to be highly advantageous in understanding and interpreting environmental data.
- (Notice that this is emerging from combining 1 and 2) To achieve public participation in environmental decision making, the public must gain access to environmental information, data and knowledge.
- (Based on 1 and 3) GIS use and output is essential for good environmental decision making.
- (Based on all the others) Public Environmental Information Systems should be based on GIS technologies. Such systems are vital for public participation in environmental decision making.
Intriguingly, the Eye on Earth White Paper notes ‘This is a very “Geospatial” centric view; however it does summarise the broader principles of Environmental Information and its use’. Yet, my intention was not to develop a ‘Geospatial’ centric view – I was synthesising what I have found, and the keywords that I have used in the search did not include GIS. Therefore, the framework should be seen as an attempt to explain the reason that GIS is so prominent.
With this framework in mind, I have noticed a change over the past decade. Throughout the summit, GIS and ‘Geospatial’ systems were central – and they were mentioned and demonstrated many times. I was somewhat surprised how prominent they were in Sha Zukang speech (He is the Undersecretary General, United Nations, and Secretary General Rio +20 Summit). They are much more central than they were when I carried out the survey, and I left the summit feeling that for many speakers, presenters and delegates, it is now expected that GIS will be at the centre of any EIS. The wide acceptance does mean that initiatives such as the ‘Eye on Earth Network’ that is based on geographic information sharing is now possible. In the past, because of the very differing data structures and conceptual frameworks, it was more difficult to suggest such integration. The use of GIS as a lingua franca for people who are dealing with environmental information is surely helpful in creating an integrative picture of the situation at a specific place, across multiple domains of knowledge.
However, I see a cause for concern for the equivalence of GIS with EIS. As the literature in GIScience discussed over the years, GIS is good at providing snapshots, but less effective in modelling processes, or interpolating in both time and space, and most importantly, is having a specific way of creating and processing information. For example, while GIS can be coupled with system dynamic modelling (which was used extensively in environmental studies – most notably in ‘Limits to Growth’) it is also possible to run such models and simulations in packages that don’t use geographic information – For example, in the STELLA package for system dynamics or in bespoke models that were created with dedicated data models and algorithms. Importantly, the issue is not about the technical issues of coupling different software packages such as STELLA or agent-based modelling with GIS. Some EIS and environmental challenge might benefit from different people thinking in different ways about various problems and solutions, and not always forced to consider how a GIS play a part in them.
Following successful funding for the European Union FP7 EveryAware and the EPSRC Extreme Citizen Science activities, the department of Civil, Environmental and Geomatic Engineering at UCL is inviting applications for a postdoctoral position and 3 PhD studentships. Please note that these positions are open to students from any EU country.
These positions are in the ‘Extreme Citizen Science’ (ExCiteS) research group. The group’s activities focus on the theory, methodologies, techniques and tools that are needed to allow any community to start its own bottom-up citizen science activity, regardless of the level of literacy of the users. Importantly, Citizen Science is understood in the widest sense, including perceptions and views – so participatory mapping and participatory geographic information are integral parts of the activities.
The research themes that the group explores include Citizen Science and Citizen Cyberscience; Community and participatory mapping/GIS; Volunteered Geographic Information (OpenStreetMap, Green Mapping, Participatory GeoWeb); Usability of geographic information and geographic information technology, especially with non-expert users; GeoWeb and mobile GeoWeb technologies that facilitate Extreme Citizen Science; and identifying scientific models and visualisations that are suitable for Citizen Science.
Research Associate in Extreme Citizen Science – a 2-year, postdoctoral research associate position commencing 1 May 2011.
The research associate will lead the development of an ‘Intelligent Map’ that allows non-literate users to upload data securely; and the system should allow the users to visualise their information with data from other users. Permissions need to be developed in accordance with cultural sensitivities. As uploaded data from multiple users sharing the same system increase over time, repeating patterns will begin to emerge that indicate particular environmental trends.
The role will also include some general project-management duties, guiding the PhD students who are working on the project. Travel to Cameroon to the forest communities that we are working with is necessary.
Complete details about this post and application procedure are available on the UCL jobs website.
PhD Studentship – understanding citizen scientists’ motivations, incentives and group organisation – a 3.5-year fully funded studentship. We are looking for applicants with a good honours degree (1st Class or 2:1 minimum), and an MA or MSc in anthropology, geography, sociology, psychology or related discipline. The applicant needs to be familiar with quantitative and qualitative research methods, and be able to work with a team that will include programmers and human-computer interaction experts who will design systems to be used in citizen science projects. Travel will be required as part of the project. A willingness to live for short periods in remote forest locations in simple lodgings, eating local food, will be necessary. French language skills are desirable.
The research itself will focus on motivations, incentives and understanding of the needs and wishes of participants in citizen science projects. We will specifically focus on engagement of non-literate people in such projects and need to understand how the process – from data collection to analysis – can be made meaningful and useful for their everyday life. The research will involve using quantitative methods to analyse large-scale patterns of engagement in existing projects, as well as ethnographic and qualitative study of participants. The project will include working with non-literate forest communities in Cameroon as well as marginalised communities in London.
Complete details about this post and application procedure are available on the UCL jobs website.
PhD Studentship in geographic visualisation for non-literate citizen scientists - a 3.5-year fully funded studentship. The applicant should possess a good honours degree (1st Class or 2:1 minimum), and an MSc in computer science, human-computer interaction, electronic engineering or related discipline. In addition, they need to be familiar with geographic information and software development, and be able to work with a team that will include anthropologists and human-computer interaction experts who will design systems to be used in citizen science projects. Travel will be required as part of the project. A willingness to live for short periods in remote forest locations in simple lodgings, eating local food, will be necessary. French language skills are desirable.
Complete details about this post and application procedure are available on the UCL jobs website.
In addition, we offer a PhD Studentship on How interaction design and mobile mapping influences participation in Citizen Science, which is part of the EveryAware project and is also open to any EU citizen.
7 March, 2011
Challenging Engineering is an EPSRC programme aimed at supporting individuals in building a research group and to ‘establish themselves as the future leaders of research’. As can be imagined, this is a both prestigious and well-funded programme – it provides enough resources to establish a group, recruit postdoctoral and PhD researchers, visit external laboratories and run innovative research activities.
The process of selecting the UCL candidates started in mid-May 2010, with the final interviews at the end of December, just before the Christmas break. Therefore, it was very satisfying to open the email from EPSRC while at a visit to the Technion and see that my application will be funded.
The proposal itself focused on Citizen Science – the participation of amateurs, volunteers and enthusiasts in scientific projects – which is not new, given activities such as the Christmas Bird Count or the British Trust for Ornithology Survey, in which volunteers observe birds and report to a national repository. Such projects date back to the early 20th century, and many of the temperature records used in climate modelling today have been collected by amateur enthusiasts operating their own weather stations.
Over the past decade, Web 2.0 technologies have led to the proliferation of Citizen Science activities, from SETI@Home, where people volunteer their unused computer processing power, to Galaxy Zoo, where amateur astronomers suggest interpretations of images from the Hubble telescope, to the Pepys Estate in Deptford, London, where residents carried out community noise monitoring for six weeks to challenge the activities of a local scrapyard operator.
However, the current range of Citizen Science projects is limited in several respects. First, in most instances the participants are trusted only as passive participants (by donating CPU cycles), or as active participants but limited to basic observation and data collection. They do not participate in problem definition or in the scientific analysis itself. Second, there is an implicit assumption that participants will have a relatively advanced level of education. Third, and largely because of the educational requirements, Citizen Science occurs mostly in affluent places, and therefore most of the places that are critical for encouraging biodiversity conservation, and where population growth is most rapid, are effectively excluded.
The new research group will challenge this current mode of Citizen Science by suggesting the establishment of an interdisciplinary team that will focus on ‘Extreme’ Citizen Science (ExCiteS). ExCiteS is extreme in three ways: first, it aims to develop the theories and methodologies to allow any community to start a Citizen Science project that will deal with the issues that concern them – from biodiversity to food production; second, it will provide a set of tools that can be used by any user, regardless of their level of literacy, to collect, analyse and act on information by using established scientific methods; finally, it aims to use the methodologies of Citizen Science around the globe, by developing a technology, through collaborative activities, that can involve communities from housing estates in London to hunter-gatherers and forest villagers in the Congo Basin. The underlying technology is intended to be universal and to provide the foundations for many other projects and activities.
The technology that will be developed will rely on spatial and geographical representations of information. The reason for focusing on this mode of representation is that, as a form of human communication, geographical representations predate text, and are likely to be accessible by many people with limited reading and technology literacy.
ExCiteS has the transformative potential to deal with some of the major sustainability challenges involved in using science and Information and Communication Technologies in a hot (due to climate change), flat (due to globalisation) and crowded (due to population increase) world, by creating tools that will help communities understand their environment as it changes, and manage it by using scientific modelling and management methods.
The proposal focuses not only on the development of ExCiteS as a practice, but, significantly, on developing a fundamental understanding of Citizen Science by studying the motivation of participants and their incentives, identifying patterns of data collection, and dealing with the uncertainty and validity of data collected in this way.
The activities of the ExCiteS group will officially start in May, and I will be working closely with Dr Jerome Lewis, at UCL Anthropology, to develop the area of Extreme Citizen Science. We are going to start by recruiting a postdoctoral fellow and 2 PhD students – so if you are interested in this type of challenge, get in touch.
10 February, 2011
In 2009, Ud Doron, who studied on our MSc in Environmental Systems Engineering developed a research project together with Tse-Hui Teh, who is doing her PhD on urban water issues. The project was co-supervised by Sarah Bell.
The focus of the project was on a series of participatory workshops to understand the relationships between urban residents and water technology. The workshops explored the perceptions and actions of environmentally aware citizens. Ud also explored the use of environmental information by the participants of the workshops. The output of this work is now written and published in the Water and Environment Journal.
The paper is titled Public engagement with water conservation in London
The abstract is:
Understanding water demand and consumers’ capacity for change is essential in underpinning water demand management and water efficiency programmes. This paper presents the outcomes of a qualitative study, which used discussion groups relating to water infrastructure with environmentally aware citizens in five London boroughs in the Lower Lea River Basin. The results showed a subtle interaction between users, water and technology. Users are generally unaware of their own water consumption. Individual perceptions of changes in water behaviour are constrained by habit and lack of knowledge about what changes can be made and how. Knowledge of environmental information was described as the inspiration behind making any changes. The paper concludes that access to information about water resources, infrastructure and conservation measures should be enhanced because although information sources are abundant, participants claimed they were inaccessible without considerable effort. Finally, an emphasis should also be put on helping the public form a more substantial part in environmental decisions.
and the paper is accessible in the early view section of the Water and Environment Journal http://onlinelibrary.wiley.com/doi/10.1111/j.1747-6593.2011.00256.x/full
7 January, 2011
EveryAware is a three-year research project, funded under the European Union Seventh Framework Programme (FP7).
The project’s focus is on the development of Citizen Science techniques to allow people to find out about their local environmental conditions, and then to see if the provision of this information leads to behaviour change.
The abstract of the project highlights the core topics that will be covered:
‘The enforcement of novel policies may be triggered by a grassroots approach, with a key contribution from information and communication technology (ICT). Current low-cost sensing technologies allow the citizens to directly assess the state of the environment; social networking tools allow effective data and opinion collection and real-time information-spreading processes. Moreover theoretical and modelling tools developed by physicists, computer scientists and sociologists allow citizens to analyse, interpret and visualise complex data sets.
‘The proposed project intends to integrate all crucial phases (environmental monitoring, awareness enhancement, behavioural change) in the management of the environment in a unified framework, by creating a new technological platform combining sensing technologies, networking applications and data-processing
tools; the Internet and the existing mobile communication networks will provide the infrastructure hosting this platform, allowing its replication in different times and places. Case studies concerning different numbers of participants will test the scalability of the platform, aiming to involve as many citizens as possible thanks to
low cost and high usability. The integration of participatory sensing with the monitoring of subjective opinions is novel and crucial, as it exposes the mechanisms by which the local perception of an environmental issue, corroborated by quantitative data, evolves into socially-shared opinions, and how the latter, eventually, drives behavioural changes. Enabling this level of transparency critically allows an effective communication of desirable environmental strategies to the general public and to institutional agencies.’
The project will be coordinated by Fondazione ISI (Institute for Scientific Interchange) and the Physics department at Sapienza Università di Roma. Other participants include the L3S Research Center at the Gottfried Wilhelm Leibniz Universität, Hannover, and finally the Environmental Risk and Health unit at the Flemish Institute of Technological Research (VITO).
At UCL, I will run the project together with Dr Claire Ellul. We will focus on Citizen Science, the interaction with mobile phones for data collection and understanding behaviour change. We are looking for a PhD student to work on this project so, if this type of activity is of interest, get it touch.
22 November, 2009
One of the best read that I had over the summer was David MacKay’s Sustainable Energy – without the hot air. The book (which you can download for free from his website) is easy to follow, clear and a very interesting analysis of the options open to the UK in terms of energy provision in a way that is sustainable and without reliance on fossil fuel.
David MacKay’s analysis covers the issue of energy both on the consumption and generation sides. It runs through a whole series of options by using lots of very intelligent and elegant ‘back of envelope’ calculations that show what the reasonable assumptions are for each source of energy and for its use.
What is especially fantastic with this book is the way in which a fairly complex environmental issue is made accessible through several means.
Firstly, the whole book is based on a single measure (kWh/day per person), which is explained clearly up front and then used throughout the book. This makes it easy to compare the different options.
Secondly, the book uses a clear visualisation of stack-bars to show how the different options of consumption and production add up.
Thirdly, the book is made of two parts – an easy–to-access first part, without the detailed scientific references and backing material that would make it difficult to understand, but with enough information to understand how each assertion is made. For interested readers there are technical chapters that provide all the scientific details towards the end of the book.
Altogether, it is a masterpiece of environmental information communication, which is very rare, unfortunately.