From	Wolfgang Cramer	Date	Fri, 16 Mar 2001 22:17:24 +0100
To	F. Ian Woodward, Nigel W. Arnell, Alberte Bondeau, Almut Arneth, Anabel Sanchez, Andreas Schuck, Anne de la Vega-Leinert, Ari Pussinen, Bärbel Zierl, Ben Smith, Bruce Beck, Carlo Jaeger, Carlos Gracia, Colin Prentice, Denis Peter, Eduard Pla, Frits Mohren, Fritz Reusswig, Harald Bugmann, Jari Liski, Jo House, Jordi Vayreda, José Manuel Moreno, Juanjo Ibañez, Mark Rounsevell, Martin Sykes, Miguel B Araujo, Mike Hulme, Pete Smith, Pierre Friedlingstein, Riccardo Valentini, Richard Klein, Rik Leemans, Sandra Lavorel, Santi Sabaté, Sergey Venevski, Stephen Sitch, Timothy Carter, Timo Karjalainen, Torben Christensen, Wolfgang Knorr, Wolfgang Lucht
Subject	Vulnerability in ATEAM
Content-Type: text/plain; charset=ISO-8859-1 X-MIME-Autoconverted: from 8bit to quoted-printable by spdmraac.compuserve.com id QAA21095 Dear everybody, I am still busy compiling the report from the kickoff meeting (and I also still await some input pieces from some of you...). For those of you who could not be there, let me just say that I enjoyed very much to see the group here, and to witness the really lively and productive discussions. Let's keep it that way. While U wait for the report - I would like to get you thinking about the project again by circulating the second draft of a small piece which is edging towards a working definition of vulnerability, mostly written by Richard and with input from Pete, Miguel and myself. All comments are welcome. This is not intended for publication of course, but it could be a start of something more substantial in due course. So please send me the elements still missing for the overall report, and comment to the four authors about the vulnerability piece. Best regards, Wolfgang -- Wolfgang Cramer Department of Global Change and Natural Systems Potsdam Institute for Climate Impact Research PO Box 60 12 03, D-14412 Potsdam, Germany Tel.: +49-331-288-2521, Fax: +49-331-288-2600 mailto:Wolfgang.Cramer@pik-potsdam.de http://www.pik-potsdam.de/~cramer ---------------------------------------------------------------------- NOTE: IF YOU NEED TO SEND ATTACHMENTS TO ME, PLEASE: 1) avoid sending MS-Word *.doc files (send rtf instead) 2) if the attachments exceed 500kB, contact me before sending anything ---------------------------------------------------------------------- PS: Sticking to my promise to avoid attachments, I send the plain ascii text here. Some time Monday you should find the pdf of it on the web site. Internal ATEAM document “Towards a definition of vulnerability…” – do not cite Draft version 2.0 (16/3/01) TOWARDS A DEFINITION OF VULNERABILITY OF ECOSYSTEM FUNCTIONING TO GLOBAL CHANGE Richard J.T. Klein, Pete Smith, Miguel B. Araújo and Wolfgang Cramer This document aims to stimulate the discussion of vulnerability to global change, which is a key feature of the EU project Advanced Terrestrial Ecosystem Analysis and Modelling (ATEAM). The goal of ATEAM is to develop an operational quantitative assessment of vulnerability across European ecosystems. The rationale for this assessment and its initial elements are also found in this document. Common features in present definitions of vulnerability Vulnerability is a multi-dimensional concept that has been a topic of study in many different scientific disciplines, ranging from anthropology and psychology to economics and ecology. As such, it has been defined and assessed in many different ways for many different purposes. The scientific literature provides many examples of vulnerability assessments, each with their own explicit or (more often) implicit interpretations of what vulnerability means to the object of study. In spite of this diversity the various interpretations of vulnerability have a number of things in common: 1. Vulnerability is always an attribute of a system, in the broadest meaning of the term. Systems that may be vulnerable include individual people, communities, countries, economic sectors, landscapes, resources, ecosystems and so on. Importantly, in ATEAM the system of interest is not ecosystems per se but the set of functions that ecosystems perform in providing goods and services to human society. 2. Vulnerability always refers to some potential of or exposure to harm or damage. It is therefore meaningful to specify exactly to which forcing a system is thought to be vulnerable. In ATEAM multiple forcings are considered, all related in some way to global change. In response to needs expressed by the European Commission these forcings are the increasing atmospheric concentration of CO2, the climate change that is the result of this increasing concentration, as well as the effects of changing land use and land-use policies. 3. Definitions of vulnerability tend to capture some notion of the extent to which the system would be unable to avoid, defend itself against, cope with, adjust to or otherwise prevent or minimise potential harm or damage. This mechanism of damage prevention or minimisation (termed adaptation in the context of climate change) is important because it defines the difference between the potential harm or damage and the actual or residual impacts that will occur. It can be argued that if a stress-exposed system has the ability to avert the potentially severe impacts that could ensue from this stress, then it is not vulnerable (footnote 1). The first assessments of vulnerability to climate change (such as the First and Second Assessment Reports of the IPCC and many national vulnerability studies) were carried out without considering adaptation as an important aspect of vulnerability. These assessments implicitly assumed present- day behaviour and activities to continue unchanged in the future, irrespective of how they would be affected by climate change. By ignoring adaptation these studies did not distinguish between potential and residual impacts and thus their results represented serious overestimates of the system’s vulnerability. On the other hand, the studies served to generate awareness of the potential magnitude of impacts and of the need for adaptation. A recent discussion of vulnerability: the IPCC Working Group II Each of the aforementioned features of vulnerability was incorporated in the proposed definition of vulnerability in the IPCC Working Group II Third Assessment Report, which was as follows: The degree to which a system is sensitive to and unable to cope with adverse impacts of climatic stimuli. Vulnerability is a function of a system’s exposure and its adaptive capacity. However, the IPCC Working Group II Plenary meeting in Geneva (13–16 February 2001) adopted a somewhat modified and expanded definition in the final, government-approved version of the Summary for Policymakers. The adopted definition no longer captures the important notion that vulnerability depends on both potential impacts and the inability to cope with these impacts, as was indicated by the word “and” in the first sentence of the above definition: The degree to which a system is susceptible to, or unable to cope with, adverse effects of climatic change, including climate variability and extremes. Vulnerability is a function of the character, magnitude and rate of climate variation to which a system is exposed, its sensitivity, and its adaptive capacity. Building blocks for a definition to be used in ATEAM The former definition of vulnerability captures the various aspects of vulnerability discussed above but it is likely to be too broad to be made operational in ATEAM. ATEAM addresses the interaction between ecosystems and society and in particular the provision of goods and services by ecosystems for human use. Of relevance to ATEAM are therefore not only the exposure and adaptive capacity of ecosystems to climate change but also the adaptive capacity of human systems in relation to a change in the provision of ecosystem goods and services. To develop a meaningful definition of vulnerability for ATEAM it could be useful to explore a number of related concepts: risk, sustainability and resilience. A relatively widely accepted interpretation of risk is that it is a function of the probability of occurrence of an event combined with an estimate of the magnitude of its impact. For example, in the context of species conservation risk can be seen as a measure of the probability that a negative event (i.e., a threat) combined with the individual species’ response to these events (i.e., an indicator of species’ vulnerability) would lead a species to extinction (Araújo and Williams, 2000). Amongst the many definitions of sustainability, a useful one is based on the conservation and substitutability of different types of capital: human-made capital, natural capital, human capital and social capital (Serageldin and Steer, 1994). Sustainable development, of which the most widely used definition is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (WCED, 1987), prescribes that the total stock of capital does not decrease over time. Whether or not substitution and compensation of different types of capital are allowed depends on the preferred level of sustainability (cf. weak versus strong sustainability). The relationship between sustainability and ecosystem vulnerability is based on the extent to which external forcings lead to a decrease in natural capital and thus in the potential of ecosystems to provide goods and services for human use. A possible (anthropocentric) definition of sustainability in the context of ATEAM could therefore be: The ability of an ecosystem to provide humans with goods and services in the present, without compromising the ability of future human generations to obtain these ecosystem goods and services in the future. The concept of resilience is well known in ecology, although two distinct interpretations of the term exist. As defined by Holling (1973), resilience determines the persistence of relationships within a system and is a measure of the ability of these systems to absorb changes and still persist. According to Pimm (1984), however, resilience describes the speed with which a system returns to its original state following a perturbation. Holling (1973), on the other hand, considered this to be the stability of a system, whilst Pimm (1984) referred to stability as the combination of resilience, resistance, persistence and variability. In an attempt to define the resilience of the Dutch coast, Klein et al. (1998) distinguished between a morphological, an ecological and a socio-economic component of coastal resilience, each of which represents another aspect of the coastal system’s capacity to cope with perturbations. They described coastal resilience as a measure of the extent to which a coast is able to respond to external pressures without losing actual or potential functions: The resilience of the coast is its self-organising capacity to preserve actual and potential functions of coastal systems under the influence of changing hydraulic and morphological conditions. This capacity is based on the (potential) dynamics of morphological, ecological and socio- economic processes in relation to the demands that are made by the functions to be preserved. Given the focus of ATEAM on ecosystem services, we might want to work towards a similar type of definition of vulnerability, whereby vulnerability could be described in terms of the likelihood that an ecosystem loses a significant amount of its capacity to provide goods and services that are important to society. A definition that includes the temporal dimension of global change and sustainability could describe vulnerability in terms of the risk of ecosystem sustainability being compromised. Before suggesting a “final” definition, however, we would like to invite views and suggestions from the entire ATEAM consortium. References Araújo, M.B. and Williams, P.H., 2000: Selecting areas for species persistence using occurrence data. Biological Conservation, 96(3), 331–345. Holling, C.S., 1973: Resilience and stability of ecological systems. Annual Review of Ecology and Systematics, 4, 1–24. Klein, R.J.T., M.J. Smit, H. Goosen and C.H. Hulsbergen, 1998: Resilience and vulnerability: coastal dynamics or Dutch dikes? The Geographical Journal, 164(3), 259–268. Pimm, S.L., 1984: The complexity and stability of ecosystems. Nature, 307, 321–326. Serageldin, I. and A. Steer (eds.), 1994: Making Development Sustainable: From Concepts to Action. Environmentally Sustainable Development Occasional Paper Series No. 2, World Bank, Washington DC, iii+40 pp. (WCED) World Commission on Environment and Development, 1987: Our Common Future, Oxford University Press, Oxford, UK, xv+383 pp. _______________________________ 1 In this document we do not elaborate on the possible different interpretations of adaptation. Adaptation will be the subject of more detailed discussion at a later stage, aimed at an appropriate (semi-) quantitative operationalisation. Attachment Converted: "c:\eudora\attach\vCard.vcf"