Margot Neyret

Andrea Larissa Boesing

Gaëtane Le Provost

Sophie Peter

Neema R Kinabo

G Dickson

Koggani D Mauki

Andreas Koggani

Berta Thiel

Peter Martín-López

Manning

Dickson G Mauki

Koggani D Koggani

Andreas Thiel

Berta Martín-López

Peter Manning

Expanding ecosystem multifunctionality measures to operationalize the IPBES framework

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

There is growing awareness that global environmental challenges cannot be solved by the natural sciences alone, leading to a surge in interdisciplinary research that addresses interlinked societal and environmental challenges [START_REF] Gain | Sustainability of complex social-ecological systems: methods, tools, and approaches[END_REF] . To enable this work, many frameworks that describe Social-Ecological Systems (SES) have been developed [START_REF] Colding | Exploring the social-ecological systems discourse 20 years later[END_REF][START_REF] Dee | Do Social-Ecological Syndromes Predict Outcomes for Ecosystem Services? -a Reply to Bodin et al[END_REF][START_REF] Mehring | Halting biodiversity loss: how social-ecological biodiversity research makes a difference[END_REF][START_REF] Ostrom | A General Framework for Analyzing Sustainability of Social-Ecological Systems[END_REF] , and there is a parallel trend in the increasing availability of ecological, socio-economic, and cultural data that allow their operationalization [START_REF] Neyret | Landscape management strategies for multifunctionality and social equity[END_REF][START_REF] Tucker Lima | A social-ecological database to advance research on infrastructure development impacts in the Brazilian Amazon[END_REF] .

A much-used SES framework is that of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) [START_REF] Díaz | Assessing nature's contributions to people[END_REF][START_REF] Díaz | The IPBES Conceptual Framework -connecting nature and people[END_REF] . This framework aims to integrate the full cycle of interactions from nature to human quality of life via nature's contributions to people (NCP), i.e. "all the contributions both positive and negative of living nature to people's quality of life" 1 ; but also the feedback from social and anthropogenic drivers onto nature [START_REF] Díaz | The IPBES Conceptual Framework -connecting nature and people[END_REF] .

The IPBES conceptual framework was designed primarily for the science-policy interface, and despite the widespread adoption of this framework within academic research, quantitative and integrated operationalization of the IPBES conceptual framework in real-world systems has, to date, been scarce [START_REF] Chaplin-Kramer | Scale matters in service supply[END_REF] . This is partly due to the conceptual and methodological challenges posed by the integration of social and ecological concepts and data.

Here, we present a new approach to quantifying the links between the different components of the IPBES conceptual framework, that considers both social and ecological concepts, and builds upon the ecosystem service multifunctionality framework (hereafter multifunctionality; [START_REF] Manning | Redefining ecosystem multifunctionality[END_REF] ). Multifunctionality is defined as the ability of ecosystems to simultaneously provide multiple NCP, relative to their prioritisation by stakeholders [START_REF] Linders | Stakeholder priorities determine the impact of an alien tree invasion on ecosystem multifunctionality[END_REF][START_REF] Manning | Redefining ecosystem multifunctionality[END_REF] . In this article, we present some of the current challenges to quantifying the interactions between SES components within the IPBES conceptual framework, before proposing some solutions, based on the multifunctionality approach.

Challenges in quantifying the IPBES conceptual framework

The great complexity of SES [START_REF] Brown | How can social-ecological system models simulate the emergence of social-ecological crises?[END_REF] is recognised by the IPBES conceptual framework, which is organised around six main components which interact and feedback into each other. Ecosystem structure and condition ("Nature", Fig. 1 box 1) determines the supply of NCP (Fig. 1, box 2), which in turn affects people's quality of life (Fig. 1, box 3). These relationships are modulated by several factors, including anthropogenic assets (Fig. 1, box 5) and institutional drivers (Fig. 1, box 6) that can mediate, for instance, the human contribution to NCP (NCP co-production), such as physical and social access [START_REF] Bruley | Nature's contributions to people: coproducing quality of life from multifunctional landscapes[END_REF] . These social components can also affect natural and anthropogenic drivers (Fig. 1, box 4), which feed back into ecosystems. The very comprehensive nature of this framework necessitates great simplification of the complexity of SES as adequate qualitative or quantitative description of each linkage is methodologically demanding [START_REF] Brown | How can social-ecological system models simulate the emergence of social-ecological crises?[END_REF] .

To date, quantification of the IPBES framework components has been mostly undertaken within the natural sciences, with most work concentrated on the relationships between Nature and NCP (Fig. 1; box 1 -> 2), and between Direct Drivers and Nature 24,25 (Fig. 1; box 4 -> 1). By contrast, most links involving anthropogenic and societal aspects have been studied qualitatively, e.g. the links between anthropogenic assets and NCP [START_REF] Fischer | Coproduction of ecosystem services as human-nature interactions-An analytical framework[END_REF][START_REF] Palliwoda | Zoning of UNESCO Biosphere Reserves: A Comprehensive Set of Geodata for Europe[END_REF] (Fig. 1; box 5 -> 2) and those between Institutions and Indirect Drivers to NCP 28 (Fig. 1; box 6 -> 2, 3). In addition, quantitative assessments of the relationships between Nature and NCP (e.g. Fig. 1; box 1 -> 2) or between Direct drivers and Nature (Fig. 1, box 4 -> 1) often only investigate individual NCP, rather than integrating multiple (but see [START_REF] Bennett | Understanding relationships among multiple ecosystem services[END_REF][START_REF] Giling | A niche for ecosystem multifunctionality in global change research[END_REF][START_REF] Raudsepp-Hearne | Ecosystem service bundles for analyzing tradeoffs in diverse landscapes[END_REF][START_REF] Spake | Unpacking ecosystem service bundles: Towards predictive mapping of synergies and trade-offs between ecosystem services[END_REF] ). As a result, they are unable to capture the complexity of ecosystem-NCP relationships, measure the synergies and trade-offs between multiple NCP, or quantify the overall impact of ecosystem changes on people's quality of life.

Besides, while NCP include both positive and negative contributions 1 , little work has considered detrimental NCP [START_REF] Shackleton | Unpacking Pandora's Box: Understanding and Categorising Ecosystem Disservices for Environmental Management and Human Wellbeing[END_REF] . Yet multiple studies have highlighted the impact of detrimental NCP, such as pests, diseases, and ecosystem greenhouse gas emissions on human quality of life [START_REF] Blanco | Ecosystem disservices matter: Towards their systematic integration within ecosystem service research and policy[END_REF][START_REF] Campagne | Looking into Pandora's Box: Ecosystem disservices assessment and correlations with ecosystem services[END_REF][START_REF] Larson | Subjective evaluations of ecosystem services and disservices: an approach to creating and analyzing robust survey scales[END_REF][START_REF] Speak | An ecosystem service-disservice ratio: Using composite indicators to assess the net benefits of urban trees[END_REF][START_REF] Pascual-Rico | Usually hated, sometimes loved: A review of wild ungulates' contributions to people[END_REF] . Thus, their integration is essential if we are to make NCP assessments representative of the overall relationship between nature and people.

At the interface of natural and social sciences lies another challenge: relating NCP supply to the benefits and detriments that humans experience. First, the benefits and detriments received depend on the ability of people to access NCP supply because of limits imposed by biophysical, social, economic and institutional factors [START_REF] Hicks | Social, institutional, and knowledge mechanisms mediate diverse ecosystem service benefits from coral reefs[END_REF][START_REF] Kachler | Coproduction of nature's contributions to people: What evidence is out there?[END_REF] . Access can vary widely across individuals and groups and can strongly affect the benefits that each perceives [START_REF] Lapointe | Urbanization alters ecosystem service preferences in a Small Island Developing State[END_REF] . Yet, access is rarely accounted for in NCP research.

Another major limitation in quantitative NCP evaluation is capturing the many values of nature 42 in comparable metrics. There is a need to acknowledge both the material and nonmaterial benefits derived from multiple NCP (as proposed in socio-cultural valuation techniques [START_REF] Peter | Cultural Worldviews Consistently Explain Bundles of Ecosystem Serivce Prioritisation Across Rural Germany[END_REF][START_REF] Iniesta-Arandia | Socio-cultural valuation of ecosystem services: uncovering the links between values, drivers of change, and human well-being[END_REF][START_REF] Schmidt | Testing socio-cultural valuation methods of ecosystem services to explain land use preferences[END_REF] ) to allow for the quantitative comparison and integration of the multiple values of nature [START_REF]Methodological assessment of the diverse values and valuation of nature of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services[END_REF] . Yet, most NCP studies use valuation methods that are hard to transfer across the multiple types of NCP. Economic assessments, which estimate the monetary benefits obtained at any given level of supply [START_REF] Newton | Ecological restoration of agricultural land can improve its contribution to economic development[END_REF][START_REF] Richter | A guide to assess and value ecosystem services of grasslands[END_REF] , are best-suited to value material NCP [START_REF] Martín-López | Tradeoffs across value-domains in ecosystem services assessment[END_REF] . For instance, benefits from agricultural production can be broadly estimated as the product of yield and market value, minus production, processing and marketing costs [START_REF] Scheper | Biodiversity and pollination benefits trade off against profit in an intensive farming system[END_REF] . Some studies have also proposed monetary valuation methods for non-material NCP, including the natural capital accounts, which estimate market prices for non-marketable NCP [START_REF] Bateman | The natural capital framework for sustainably efficient and equitable decision making[END_REF] . Examples include the medical costs avoided by obtaining physical and mental health benefits from being in contact with nature [START_REF] Bratman | Nature and mental health: An ecosystem service perspective[END_REF] and the travel costs incurred by people when visiting nature [START_REF] Martín-López | Effects of spatial and temporal scales on cultural services valuation[END_REF][START_REF] Riera Font | Mass Tourism and the Demand for Protected Natural Areas: A Travel Cost Approach[END_REF] . However, such approaches are considered contentious as they do not represent the diversity of values associated with NCP [START_REF] Gunton | Beyond Ecosystem Services: Valuing the Invaluable[END_REF] . For instance, they poorly represent the intangible benefits of non-material NCP [START_REF] Gunton | Beyond Ecosystem Services: Valuing the Invaluable[END_REF] , e.g. people's sense of place associated with a particular ecosystem [START_REF] Topp | Decision-making for nature's contributions to people in the Cape Floristic Region: the role of values, rules and knowledge[END_REF] .

Finally, perhaps the largest challenge is in quantitatively integrating the wider social system with that of the typically quantified natural components of the SES. Addressing this issue requires linking changes in NCP and quality of life to changes in the numerous components of the human social system, including economics, institutions, governance, values and technology. These can impact multiple of the above-mentioned components, including ecosystem management, via a range of pathways such as policy changes, access through e.g. legal rights, or valuation of different NCP. These aspects are rarely represented quantitatively, and thus often difficult to integrate with that of NCP research.

This list of challenges, while non-exhaustive, highlights the need for a quantitative approach that integrates aspects of NCP supply, access, and valuation. In the sections that follow, we introduce the current multifunctionality framework and describe its expansion to meet some of these challenges. The objective of the approach is to provide ways to better quantify some links between NCP and quality of life, anthropogenic assets and institutions/indirect drivers and NCP. The inset Goal box indicates the new degree of quantification if the suggested framework is implemented

Expanding the multifunctionality framework

Recently, interest in quantifying the simultaneous supply of multiple NCP has led to the adoption of multifunctionality metrics, originally devised for biodiversity research [START_REF] Byrnes | Investigating the relationship between biodiversity and ecosystem multifunctionality: challenges and solutions[END_REF][START_REF] Hölting | Measuring ecosystem multifunctionality across scales[END_REF] . One of these metrics, ecosystem service multifunctionality, integrates human and natural components by quantifying the simultaneous supply of multiple NCP, weighted by their prioritisation by people [START_REF] Linders | Stakeholder priorities determine the impact of an alien tree invasion on ecosystem multifunctionality[END_REF][START_REF] Manning | Redefining ecosystem multifunctionality[END_REF] , and accounting for the amount supplied relative to demand. In this context, prioritisation represents one element of valuation, which corresponds to the relative importance that people give to individual NCP (see below). As supply measures can be linked to ecosystem conditions, the overall impact of environmental and land-use changes on stakeholder groups can be assessed [START_REF] Linders | Stakeholder priorities determine the impact of an alien tree invasion on ecosystem multifunctionality[END_REF][START_REF] Provost | The supply of multiple ecosystem services requires biodiversity across spatial scales[END_REF][START_REF] Neyret | Assessing the impact of grassland management on landscape multifunctionality[END_REF] .

In its present form, the multifunctionality approach comprises several steps, which largely match the widely-used cascade model of ecosystem services research [START_REF] Haines-Young | The links between biodiversity, ecosystem services and human well-being[END_REF] (hereafter NCP cascade), taking into account environmental processes and conditions, as well as NCP, their societal value, and impact on quality of life (Fig. 2, box 1-3). First, all major beneficial NCP ("ecosystem services" in the original framework, here NCP terminology) in a region are identified and their supply is quantified across the considered environmental gradients (e.g. across land use types). Thereafter, the NCP prioritisation is obtained from stakeholders using a standardised scoring technique. NCP supply is then converted into benefits received by stakeholders through a 'supply-benefit' relationship. Finally, the benefit scores obtained through the supply-benefit relationship are standardised and multiplied by priority scores representing the relative priority of each NCP to each stakeholder group. This gives each group a measure ranging from 0-1, where 1 means all NCP are provided at their maximal levels. We propose that this multifunctionality approach can be extended to quantify the "net balance of NCP" (netNCP), thus making it consistent with the general IPBES conceptual framework (Fig. 2).

In the following sections, we show how to quantify the netNCP and link this measure and its underlying components to numerous aspects of the social system. To do this we show how the multifunctionality approach 13 can be adapted and expanded to integrate with the IPBES conceptual framework. Specifically, we expand the current multifunctionality approach in four directions:

1. Include detrimental NCP (previously excluded from multifunctionality assessments), thus deriving an overall measure of the net balance of both benefits and detriments: netNCP (Fig. 2, box 1).

2. Incorporate access to NCP supply, by adjusting the potential supply of a given NCP to the supply that is effectively experienced via an 'access filter', i.e. accessible supply (Fig. 2, Box 1). This supports more realistic assessments that consider the level of supply actually available to, or experienced by, stakeholders.

3. Provide a formal quantitative framework for linking the supply of benefits/detriments to material and non-material benefits and detriments: the supply-benefit/detriment relationship. This is a key bridging component in linking ecosystem NCP supply to human quality of life.

4. Finally, we highlight directions for further integration of netNCP metrics into SES studies. Specifically, we point towards the need to incorporate a wider range of co-production factors that alter the NCP cascade, and to quantify and represent the interface between the social system and the NCP cascade in greater detail, which is the first step towards assessing the impact of changes in the social system (such as in governance and economics). We also stress the need to incorporate temporal dynamics into the netNCP approach.

Since the most appropriate data acquisition methods are likely to differ depending on the scale of analysis, we present a framework that is tailored for relatively small SES scales, ranging from village to province. We also provide a worked-through example of this expansion (Box 1). The starting point in measuring netNCP is the identification of all NCP relevant to stakeholders (identified through stakeholder analyses), and their means of quantification using appropriate indicators (Fig 2 ,box 1). This can be done through focus group discussions, workshops or interviews in which relevant stakeholders list the different NCP that they demand [START_REF] Peter | Cultural Worldviews Consistently Explain Bundles of Ecosystem Serivce Prioritisation Across Rural Germany[END_REF][START_REF] Martín-López | A novel telecoupling framework to assess social relations across spatial scales for ecosystem services research[END_REF] . Particular attention should be given to non-material and detrimental NCP, which are often overlooked in NCP assessments [START_REF] Blanco | Ecosystem disservices matter: Towards their systematic integration within ecosystem service research and policy[END_REF][START_REF] Martín-López | A novel telecoupling framework to assess social relations across spatial scales for ecosystem services research[END_REF][START_REF] Daniel | Contributions of cultural services to the ecosystem services agenda[END_REF] . Omitting these risks misrepresenting the benefits provided by nature to society, and biassing the assessments towards certain NCP or stakeholders. The final list of NCP can rely on global NCP classifications such as the one proposed by IPBES 9 but should be tailored to local contexts, for instance by using interviews and focus group discussions to identify all context-specific detrimental and beneficial NCP that are prioritised by local stakeholders [START_REF] Topp | Decision-making for nature's contributions to people in the Cape Floristic Region: the role of values, rules and knowledge[END_REF][START_REF] Newman | The contributions of nature to people within the Yawuru Indigenous Protected Area[END_REF] . These should be restricted to NCP that directly affect stakeholders ("final benefits" 60 ) rather than those that underlie other NCP to avoid double-counting of some NCP. For instance, pollination usually does not benefit stakeholders directly, but indirectly by underpinning the production of many crops; it should not be included so as not to overemphasise the importance of this NCP to people.

Once a list of all NCP is produced, reliable and context-relevant indicators should be identified for each NCP. While there has been significant progress in identifying indicators for beneficial NCP in the past years [START_REF] Richter | A guide to assess and value ecosystem services of grasslands[END_REF] , such assessments are lacking for non-material and detrimental NCP (but see [START_REF] Tribot | Integrating the aesthetic value of landscapes and biological diversity[END_REF] ). For non-material NCP, participatory approaches such as photo-elicitation 65 can be used to identify appropriate indicators, e.g. ecosystem components that are culturally valued [START_REF] Bieling | Recording Manifestations of Cultural Ecosystem Services in the Landscape[END_REF][START_REF] Darvill | The inclusion of stakeholders and cultural ecosystem services in land management trade-off decisions using an ecosystem services approach[END_REF] . Meanwhile, suitable data may already be available for many detrimental NCP, though in literature that are often not included in the SES discourse, such as human-wildlife conflicts [START_REF] Pascual-Rico | Usually hated, sometimes loved: A review of wild ungulates' contributions to people[END_REF][START_REF] Lozano | Human-carnivore relations: A systematic review[END_REF] , zoonotic diseases [START_REF] Combs | Socio-ecological drivers of multiple zoonotic hazards in highly urbanized cities[END_REF] or agricultural pests [START_REF] Qiu | Effects of Landscape Pattern on Pollination, Pest Control, Water Quality, Flood Regulation, and Cultural Ecosystem Services: a Literature Review and Future Research Prospects[END_REF] . While as many NCP as possible should be included for a complete and representative assessment, efforts should particularly be concentrated to obtain reliable indicators for the NCP identified by stakeholders as having the highest impact on their well-being [START_REF] Ausseil | A Novel Approach to Identify and Prioritize the Connections Between Nature and People's Well-Being in New Zealand[END_REF] and/or highest priorities, as these will have the largest impact on netNCP. When site-level data is unavailable, values can be estimated from processbased, phenomenological or proxy-based models [START_REF] Lavorel | Pathways to bridge the biophysical realism gap in ecosystem services mapping approaches[END_REF] , especially for less prioritised NCP.

Finally, these indicators or proxies are converted into supply estimates. If only one indicator per NCP is available, this can be as simple as equating NCP supply to the value of the indicator. When multiple indicators are available for a single NCP (e.g. taxonomic and functional diversity for the aesthetic value of coral reefs [START_REF] Tribot | Taxonomic and functional diversity increase the aesthetic value of coralligenous reefs[END_REF] ), they can be scaled, weighted by their importance, and averaged into an estimate of overall supply.

3.2 From NCP supply to benefits (Fig. 2

box 2)

Accounting for access to NCP

The NCP supply estimated from the above-mentioned indicators usually corresponds to potential supply, i.e. the maximum NCP supply produced by the ecosystem that could potentially be used ("supply potential" 7 (Spangenberg et al., 2014b). In reality, while the potential NCP supply depends on ecosystem condition, the accessible supply, i.e. that which is actually usable, depends on the ability of stakeholders to access NCP supply (Fig. 2 box 2).

Access can be broadly defined as "the ability to derive benefits from things" 8 . In addition to physical limitations (e.g. absence of roads or steep slopes), access can thus also be affected by knowledge (e.g. ability to identify useable species), socio-cultural factors such as traditions (e.g. prevention of use by cultural taboos), and economic and institutional factors (e.g. lack of financial capital to fund resource extraction, legal rights to access an area for recreation). Any of these dimensions of access can be shaped by power relations among stakeholders [START_REF] Berbés-Blázquez | Towards an ecosystem services approach that addresses social power relations[END_REF][START_REF] Berbés-Blázquez | Understanding how access shapes the transformation of ecosystem services to human well-being with an example from Costa Rica[END_REF][START_REF] Felipe-Lucia | Ecosystem Services Flows: Why Stakeholders' Power Relationships Matter[END_REF][START_REF] Vallet | Linking equity, power, and stakeholders: roles in relation to ecosystem services[END_REF] . When access can be an issue, we therefore suggest applying an "access filter" into netNCP assessments. This adjusts the potential supply of a NCP (e.g. aesthetic value of a whole landscape) by that which is accessible (e.g. proportion of the landscape that is open to visitors) to represent the accessible proportion of the potential supply (e.g. the proportion of aesthetically beautiful land that is viewable) (Box 2, step 2).

While we present the access filter as a simple proportion here (Box 1), effort may be required to estimate stakeholder-and context-specific access filters in practice, e.g. by only considering socially known species from supply measures of medicinal plants production, or estimating the proportion of supply that falls within geographic boundaries. Access drivers, such as enforcement and security of property rights, are often complex and expansion is required to link these aspects to our framework.

Linking NCP supply to material and non-material benefits

Once accessible supply has been estimated, the next key challenge in evaluating netNCP is to determine the benefit, or detriment, that stakeholders derive from a particular level of supply. This is described by supply-benefit relationships, which mathematically describe how rising supply levels of beneficial NCP are related to benefit experienced by people [START_REF] Manning | Redefining ecosystem multifunctionality[END_REF] . These can be extended to detrimental NCP, by allowing the relationship to be negative, or to become negative at certain levels (i.e., benefits decrease as supply increases, or decrease beyond an optimum). The latter approach allows us to go beyond the false dichotomy of beneficial and detrimental NCP 78 by allowing some NCP to switch between being detrimental or beneficial at certain levels. For instance, ecosystem carbon fluxes can be either beneficial (positive sequestration rates) or detrimental (negative sequestration rates, i.e. emission, Fig. 3). This can be represented by a supply-benefit relationship that gives negative and detrimental scores when ecosystems emit carbon, and positive benefit scores as the system switches to sequestration.

In addition to the direction and sign of the supply-benefit relationship, a robust estimation of the form of this relationship is important to accurately describe the actual benefits and detriments experienced. In practice, previous multifunctionality studies have usually assumed a positive and linear relationship between supply and benefits, usually due to a lack of data on the real relationship [START_REF] Linders | Stakeholder priorities determine the impact of an alien tree invasion on ecosystem multifunctionality[END_REF][START_REF] Neyret | Assessing the impact of grassland management on landscape multifunctionality[END_REF] . While the assumption that benefits increase linearly with supply is probably safe for NCP that operate at large scales (e.g., climate regulation via carbon storage [START_REF] Manning | Redefining ecosystem multifunctionality[END_REF] ), other NCP are more likely to display non-linear supply-benefit relationships. These include NCP with direct economic benefits: for instance, under a certain level of wood production, exploitation of a forest parcel might not be economically viable and will be discontinued resulting in null benefits; while above the threshold increasing production could deliver increasingly large returns due to economies of scale (Fig. 3a). Similarly, benefits from regulating NCP could saturate (e.g. water supply exceeding consumption) or become detrimental (e.g. excess rainfall turning into floods) beyond a certain threshold. Such thresholds can help assess how NCP supply relates to the overall NCP demand, i.e. how much of a NCP is needed to fully meet stakeholders' needs.

A range of methods to assess the shape of supply-benefit relationships have been described, e.g. within the natural capital approach [START_REF] Mace | Towards a risk register for natural capital[END_REF] . At its simplest, the shape of the relationship can be based on expert knowledge: for instance, using a threshold relationship to describe that benefits derived from tree-provided shade stop increasing after 50% 4 . More quantitative estimations are likely to require complementary methods depending on the considered NCP, ranging from economic assessments [START_REF] Bateman | The natural capital framework for sustainably efficient and equitable decision making[END_REF][START_REF] Mace | Towards a risk register for natural capital[END_REF] to socio-cultural valuation approaches [START_REF] Martín-López | Uncovering Ecosystem Service Bundles through Social Preferences[END_REF][START_REF] Schmitt | Plural valuation in space: mapping values of grasslands and their ecosystem services[END_REF] . These may be advanced if required by conducting additional surveys or relying on NCP use patterns [START_REF] Wolff | Mapping ecosystem services demand: A review of current research and future perspectives[END_REF] to assess how different groups may appreciate different NCP levels, or how demand shifts in response to supply. Whenever possible, complementary methods should be used to assess both the material (e.g. financial benefits from selling crop yield) and non-material (e.g. physical and mental health, social status) benefits related to each individual NCP. Further advances could involve a better representation of the costs of accessing NCP or competition for NCP, such that one person's benefit from an NCP limits the benefit received by others (as often true for provisioning services, e.g. limited amounts of timber) to link this framework to issues of resource management. Another extension would be better representation of interdependencies between the benefit provided by different NCP: for instance, the benefit level of non-essential NCP might only manifest when levels of essential NCP exceed critical levels.

The NCP accessible supply can then be transformed through the corresponding supplybenefit/detriment relationship, with final benefit and detriment scores ranging from -1 (maximum detriments) to 1 (maximum benefits) for each NCP. Combining material and non-material benefits and detriments into standardised supplybenefit/detriments relationships. Here we provide examples for two stakeholder groups (locals and foresters) for three NCP (timber production, aesthetic value, and disease prevalence). Material benefits/detriments can be assessed for each value of NCP supply through a range of methods including economic assessments [START_REF] Bateman | The natural capital framework for sustainably efficient and equitable decision making[END_REF] and should ideally be complemented by additional approaches [START_REF] Iniesta-Arandia | Socio-cultural valuation of ecosystem services: uncovering the links between values, drivers of change, and human well-being[END_REF] to assess the non-material benefits/detriments accompanying these benefits. Both material and non-material benefits will differ across stakeholders either qualitatively (e.g. local inhabitants receive no direct material benefit from the timber produced in their local environment) or quantitatively (e.g. slope and thresholds of the relationships can be income-dependent).

Measuring the net balance of NCP

To evaluate the overall balance of NCP (netNCP), final benefits and detriments must be weighted by their relative priority to people. This information can be obtained from quantitative surveys, in which respondents are asked to distribute a fixed total number of points across all NCP identified during the initial expert interviews or focus group discussions (section 3.1), according to how much they prioritise each single NCP 2 . While this can be done alongside the initial NCP identification process (section 3.1) it may be better performed as a second step, once the list is finalised and indicators identified. These priorities can be averaged across social groups, either predetermined (e.g. stakeholder groups) or data-driven (people with similar priority patterns) 2 . The relative priority of each NCP is then measured as the proportion of points attributed to it by each group, and is multiplied by the corresponding final benefits/detriments value to obtain weighted NCP scores. The weighted scores are then summed to obtain a net balance of NCP for each group, scaled between -1 (maximum supply of detrimental NCP, no beneficial NCP) and 1 (maximum supply of beneficial NCP, no detrimental NCP).

The resulting scores can be used to assess how well an ecosystem or landscape serves the needs of various stakeholder groups, incorporating multiple values. Comparative and modelling studies can also be used to estimate the effects of changes to ecosystem condition and societal priorities on the netNCP, as has been done for multifunctionality metrics [START_REF] Neyret | Assessing the impact of grassland management on landscape multifunctionality[END_REF][START_REF] Hölting | Including stakeholders' perspectives on ecosystem services in multifunctionality assessments[END_REF] . Stakeholder-level netNCP scores can be averaged across stakeholders to estimate community-level netNCP or compared across groups to evaluate how equitably NCP are distributed across groups [START_REF] Neyret | Landscape management strategies for multifunctionality and social equity[END_REF] .

Description of the hypothetical system

The hypothetical focus area is composed of coniferous, intensively managed tree plantations, mixed, extensively-managed forests and a swamp. We focus on three beneficial NCP (aesthetic value, carbon sequestration, building materials (timber) production) and one detrimental NCP (health risks, e.g. presence of disease vectors); and three stakeholder groups: foresters, landowners, and local residents. NCP differ in their degree of prioritisation by the different stakeholder groups (a) and supply by the three land use types (c). We assume different forms of supply-benefit/detriment relationships (b). Benefits from aesthetic value increase linearly with supply. Carbon sequestration leads to benefits when positive, and detriments when negative (i.e. carbon emissions). Detriments from health risks decrease linearly with supply, and benefits from timber production increase exponentially after a certain threshold of economic viability for harvest is reached (before which the benefits are null).

Scenarios and results (d, e)

We explore four different scenarios. In scenario 1, the forest area is composed of 60% coniferous forests and 40% deciduous forest. Part of the area, covering the swamp and half the forests, is privately owned, which means local residents cannot access the NCP supplied there, except for carbon sequestration, which does not require access. Foresters and landowners can access the whole area. Because most of the area is covered with coniferous forests providing the high timber production prioritised by foresters, this scenario leads to a relatively high netNCP for foresters compared to other groups.

In scenario 2, the relative proportion of the two forest types change (to 60% deciduous and 40% coniferous; the access conditions remain the same as in scenario 1. The reduction of coniferous forest cover leads to lower netNCP for foresters, and slightly higher for locals, than scenario 1.

In scenario 3, the proportion of forest types is the same as scenario 1 but the access restrictions are lifted meaning local residents now access a larger supply of beneficial NCP, such as aesthetics. However, they can also access the swamp, which hosts disease vectors. The resulting increase in health risks compensate for the obtained benefits, resulting in a close-to-null change in netNCP.

In scenario 4, the proportion of forest types is the same as in 1 and 3 and the access restrictions are also lifted. However, the netNCP calculation does not include detrimental NCP, i.e. health risks. This results in much higher netNCP values, and a change in the repartition of netNCP values across groups.

This example provides a clear demonstration of the need to consider access, detrimental NCP and a wide range of stakeholder groups in NCP assessment and corresponding environmental decision making.

Future expansion of the netNCP approach

So far, we have shown how the netNCP approach can be used to quantify and formalise several interactions between the natural and human components of the IPBES conceptual framework.

The impact of environmental drivers on netNCP (e.g. land-use, biodiversity and climate change; Fig. 1 box 4) is usually relatively well understood and represented [START_REF] Neyret | Assessing the impact of grassland management on landscape multifunctionality[END_REF][START_REF] Hölting | Including stakeholders' perspectives on ecosystem services in multifunctionality assessments[END_REF] . However, changes in the social system, including those involving technologies, institutions, socioeconomic variables, knowledge and values (Fig. 1 box 5, 6) have received less attention (but see [START_REF] Falk | Identifying governance challenges in ecosystem services management -Conceptual considerations and comparison of global forest cases[END_REF] ). A full discussion of the challenges in incorporating the social system into the netNCP approach is beyond the scope of this article, but here we discuss some potential first steps and present directions for further development.

Our first suggestion is to add a well-defined description of the interface between the natural and social systems. This allows us to see where changes in the social system can influence the netNCP cascade. Clues as to how this interface could be defined can be found in work describing ecosystem service co-production. In the IPBES conceptual framework coproduction is the modification of natural ecosystem benefits by people's interactions with them, and by inputs from anthropogenic assets 9 . Co-production includes actions related to land-use change, which alters ecosystem condition; land condition and management, which alters potential supply via co-production; and also knowledge and legal or physical access, which could affect the access filter [START_REF] Bruley | Nature's contributions to people: coproducing quality of life from multifunctional landscapes[END_REF][START_REF] Lavorel | Co-producing ecosystem services for adapting to climate change[END_REF] . Such actions can thus be seen to form an interface with multiple components of the netNCP cascade (Fig 5). Other actions might affect the supplybenefit/detriment relationship, such as increased subsidies for sustainable forest management shifting the threshold of economic viability for wood production shown in Fig. 3. Once defined, the impact of different actions along this interface can be investigated via modelling simulations or experiments. This could be an insightful means of determining how different changes to human actions would alter netNCP. For example, it would be possible to assess the sensitivity of overall netNCP to each action along the cascade by sequentially changing each netNCP parameter by a fixed proportion (e.g. +/-10%) to simulate change in this factor. This could reveal which actions affect the final netNCP score most strongly, and how much any given change, e.g. to supply or access, would affect netNCP.

As a further extension, the system governing the actions at the interface could be defined. Depending on the action, this may take the form of economic or legal systems and/or social values and preferences [START_REF] Kachler | Coproduction of nature's contributions to people: What evidence is out there?[END_REF][START_REF] Isaac | Chapter Ten -Governance to manage the complexity of nature's contributions to people co-production[END_REF] . For example, changes in income levels, market value, subsidies, or human demography could affect supply-benefit relationships, and campaigning and advertising could all alter prioritisation scores. (Fig 4). Such aspects of the social system are traditionally studied by disciplines with less established links to the environmental sciences, such as economics, psychology, political science and sociology. Quantitatively formalising the links between these social drivers and the netNCP framework requires collaboration and integration of these fields with each other and the natural sciences [START_REF] Spangenberg | Provision of ecosystem services is determined by human agency, not ecosystem functions. Four case studies[END_REF] . Connecting the NCP cascade to these disparate fields would also require the formulation of an agreed language and terminology.

Given the complexity of this issue and to avoid the development of many parallel terminologies we suggest this is best done as part of a broad consensus building exercise, e.g. via IPBES itself.

To give a more specific example of how these expansions to the netNCP approach may operate in practice, consider a change in large-scale agri-environment policy, such as the European Union's common agricultural policy [START_REF] Pe'er | Action needed for the EU Common Agricultural Policy to address sustainability challenges[END_REF]87 (Fig 5). Expert knowledge from across disciplines could define the actions at the interface (e.g. farm management practices, access to land or market) and qualitative research could identify how a policy change might cascade from written policy to the actions of legislative bodies, farmers, and conservation groups to then impact actions along the cascade, including the abundance of different land cover types, fertiliser and pesticide use, and subsidy payments. This could provide estimates of the potential change for quantitative scenarios. These could then be implemented in the NCP cascade as changes in land cover and in NCP supply in the natural part of the cascade, and as change to the supply-benefit relationship for the subsidies (red arrows Fig. 5).

Finally, another important aspect missing from the existing netNCP approach is temporal dynamics and feedbacks between its components. The approach currently takes a 'snapshot' approach, with netNCP calculated for an existing state, and future states as a new equilibrium under scenarios of change. This may fail to capture real changes in NCP supply over a range of time scales, from instant to decadal and longer, due to ecological time-lags and/or legacy effects [START_REF] Provost | Land-use history impacts functional diversity across multiple trophic groups[END_REF] , for example in the case of extinction debts [START_REF] Isbell | The biodiversity-dependent ecosystem service debt[END_REF] . As the drivers of change (either natural or anthropogenic) are currently considered as external to the system, feedback between the different components are also not considered. In real SES, feedbacks may take a range of forms, such as alteration of NCP supply following extraction and use, changes to land management as a result of current benefit levels [START_REF] Synes | Coupled land use and ecological models reveal emergence and feedbacks in socio-ecological systems[END_REF] , variation in demand following supply change, or even feedbacks between climate, biodiversity and NCP [START_REF] Pörtner | Scientific outcome of the IPBES-IPCC co-sponsored workshop on biodiversity and climate change[END_REF] . Implementing these temporal dynamics and feedbacks would bring additional insight and realism but requires careful consideration of the multiple mechanisms involved.

Conclusion

Quantitative assessments of the relationships between humans and nature are needed to reliably inform decision makers of the impact of actions, and effectively support decision-making. While the ecosystem service multifunctionality approach allowed for the impacts of biodiversity and land-use change on overall NCP supply, numerous aspects, such as access, and detrimental NCP were not represented. The netNCP approach presented here has the potential to advance human-nature relationship assessments more broadly, by allowing for a wider quantitative integration of multiple different components of the IPBES conceptual framework. In comparison to multifunctionality approaches, the netNCP framework by including detrimental NCP proposes a more representative picture of the human-nature relationship, that may shed new light on conservation and ecosystem management conflicts. Further, it allows the role of a far greater range of factors, both biophysical and societal, to be assessed, and for the impact of changes in these factors to be investigated. The modular nature of the framework allows users to invest as much effort as required by the research question into each component -making it adaptable to a range of issues and approaches. The netNCP thus provides a more robust and complete basis for the integration of ecological and social sciences that is needed to quantify SES and identify options for their more sustainable management.

Figure 1 .

 1 Figure 1. Structure of the IPBES conceptual framework, adapted from Diaz et al. 2015, showing some of the major challenges in quantifying each component. The framework recognises six main components that interact and feedback into each other. Ecosystem structure and condition determine the supply of NCP, which in turn affects quality of life. These relationships are modulated by the combination of anthropogenic assets and institutional drivers. These human components impact natural and anthropogenic drivers of nature, which feed back into ecosystem functioning. Challenges are shown in bullet points under the title of each component. The challenges specifically addressed in this paper are shown in orange type. The colour of the arrows indicates the current research underlying each of the links between components, from mostly qualitative to more quantitative. The objective of the approach is to provide ways to better quantify some links between NCP and quality of life, anthropogenic assets and institutions/indirect drivers and NCP. The inset Goal box indicates the new degree of quantification if the suggested framework is implemented

Figure 2 .

 2 Figure 2. Integration of the netNCP approach within the IPBES conceptual framework. Each component of the IPBES conceptual framework (Fig 1) relates to one or more netNCP components. Altogether, boxes 1-3 provide the overall quantification of netNCP, which can help identify key direct and indirect drivers of change (boxes 4-6).

3. 1

 1 Selection of NCP and their indicators (Fig. 2 box 1)

Figure 3 .

 3 Figure 3.Combining material and non-material benefits and detriments into standardised supplybenefit/detriments relationships. Here we provide examples for two stakeholder groups (locals and foresters) for three NCP (timber production, aesthetic value, and disease prevalence). Material benefits/detriments can be assessed for each value of NCP supply through a range of methods including economic assessments[START_REF] Bateman | The natural capital framework for sustainably efficient and equitable decision making[END_REF] and should ideally be complemented by additional approaches[START_REF] Iniesta-Arandia | Socio-cultural valuation of ecosystem services: uncovering the links between values, drivers of change, and human well-being[END_REF] to assess the non-material benefits/detriments accompanying

Figure 4 :Box 1 .

 41 Figure 4: Calculating netNCP step by step. The workflow integrates all components of netNCP from NCP potential and accessible supply, supply-benefit/detriment relationships, and priorities. Stakeholder scores shown represent averaged group values.

Figure 5 .

 5 Figure 5. Identifying the impact of social change on the netNCP cascade. In the top part of the figure, the netNCP approach follows the cascade model 60 from nature to NCP and their value to society. This interfaces with the social system as various forms of NCP co-production. The case shown in red illustrates examples of large-scale agri-environmental policy change that impacts several actions at the social-natural system interface (see text for details).

Acknowledgements

The work was partly funded by the DFG Priority Program 1374 "Infrastructure-Biodiversity-Exploratories", and by Senckenberg biodiversity and Climate Research Center.

We thank Dominic Martin for constructive feedback on a previous version of this manuscript.

Author contributions

MN, ALB, GLP, SP, NRK, DGM, KDK, PM participated in early discussions to design the framework. MN, PM led the writing of the manuscript. All authors contributed critically to the manuscript.


Aurélie Bugeau

Anne-Laure Ligozat

How digital will the future be? Analysis of prospective scenarios

HAL is

INTRODUCTION

In the context of climate change, many prospective studies have been proposed in the past years to envision possible futures. They describe the future in very different formats: some are purely narratives, while others rely on quantitative models. These studies help cope with uncertainties and challenges by expanding the available ideas and options 1. Most prospective studies present multiple scenarios (see Figure 1) resulting from different societal or technical hypotheses, each shaped by many variables, such as economic growth, well-being, sobriety, low-carbon energy, population, or uncertain events. Prospective scenarios are neither predictions nor forecasts but overviews of possible future paths [START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF]. Studies often include a baseline business-as-usual scenario used as a reference. As computer scientists, we wanted to question the place of digital technologies in these studies. Through a preliminary analysis of several scenarios, we observed that they always consider information and communication technologies (ICT) to be present in the future. However, the evolution of the ICT sector and its role in other sectors vary between scenarios. In this paper, we propose to dig further into a set of prospective studies to summarize the future of ICT they envision. More specifically, the objective of this work is to answer the following questions:

• What ICT is present in the scenarios? i.e., which infrastructure, amount of data, and technologies?

• To what extent does ICT vary among scenarios?

• What applications relying on ICT are described?

• How do the scenarios envision the role of ICT for the environmental transition?

To answer these questions, we analyzed 14 studies and their corresponding 35 scenarios, and we focused on the evolution of digital technologies and their areas of applications. We do not pretend to make an exhaustive review of existing scenarios. However, we tried to cover various scenario types, from narrations only to mainly quantitative ones, with positive or negative visions. We identified a limitation of our study, namely the selection of OECD countries-centered studies, which we discuss in Section 5.

Our contributions are to:

• Analyze digital technologies within scenarios according to a proposed set of variables organized in a comprehensive typology.

• Highlight common points and differences between scenarios.

• Identify challenges that should be addressed as research questions to enable or avoid these scenarios.

• Identify some missing aspects regarding ICT in prospective scenarios.

Section 2 presents existing work on ICT in future scenarios. Section 3, explains how we selected the studies, and discusses the variables we used to analyze the scenarios. The chosen variables are those that may influence the role of ICT in scenarios. Section 4 more specifically presents what digital technologies look like in the prospective scenarios and their area of applications. Finally, in section 5, we discuss the observations made and identify what we believe are omitted features in the studies.

RELATED WORKS

Only very few works exist regarding the place of digital technologies in prospective scenarios. In this section, we describe the works that are related to ours.

Several authors estimate future ICT energy consumption and carbon footprint [Andrae, 2019, Malmodin and[START_REF] Malmodin | [END_REF]. The projections depend on two main variables: ICT equipment and services efficiency, and demand for ICT (via possible rebound effects) [START_REF] Freitag | The real climate and transformative impact of ICT: A critique of estimates, trends, and regulations[END_REF]. Our goal here is not to quantify the future consumption of ICT but rather to analyze the possible places of ICT in the future and to explicitly state the implications it could have on its direct and indirect impacts [START_REF] Hilty | The relevance of information and communication technologies for environmental sustainability-a prospective simulation study[END_REF] of the sector.

In [START_REF] Erdmann | Scenario analysis: exploring the macroeconomic impacts of information and communication technologies on greenhouse gas emissions[END_REF], the authors propose a scenario analysis of the future impacts of ICT applications on GHG emissions. ICT being a driver of new lifestyles, structural changes, and economic growth, studying its effects is complex. The authors start by reviewing existing macroeconomics on ICT and GHG emissions and conclude that, apart from a few studies, previous works show unambiguous overall reductions of GHG emissions due to ICT. The second part focuses on building specific macroeconomic ICT impact assessment models by looking at ICT's first-, second-, and third-order effects on the environment. It extends a previous study [START_REF] Erdmann | The future impact of icts on environmental sustainability[END_REF] by focusing on data uncertainty, requiring further research, and future uncertainty indicating a need for political action. The proposed macroeconomic ICT impact assessment model is applied to the three scenarios from [START_REF] Erdmann | The future impact of icts on environmental sustainability[END_REF]. These scenarios designed in 2003 describe alternative future courses of ICT until 2020. The scenario analysis from [START_REF] Erdmann | Scenario analysis: exploring the macroeconomic impacts of information and communication technologies on greenhouse gas emissions[END_REF] concludes with the necessity of incorporating ICT in a general macroeconomic model to quantify rebound effects of energy efficiency measures and the need for a large geographical scope for a complete impact assessment of future scenarios.

Also focusing on assessing future scenarios, authors in [START_REF] Fauré | Methods for assessing future scenarios from a sustainability perspective[END_REF]] review methods for assessing future scenarios' environmental and social sustainability impacts. They consider three types of scenarios according to the classification of [START_REF] Börjeson | Scenario types and techniques: towards a user's guide[END_REF], i.e., predictive, explorative, and normative scenarios. A particular focus is put on sustainability assessments of scenarios in the ICT sector, an example of a rapidly developing sector. The study concludes that the topic of assessment requires further attention if scenarios are to be used to support policy and guide action towards sustainability. In this paper, we do not question the environmental and societal impacts assessment of the scenarios but rather compare scenarios based on the imaginaries and research questions they may drive. [Andok, 2022] proposes an analysis of the evolution of digital futures in European Union reports. The author reviews three EU reports on digital futures. The first one, [European Commission, 2014], published in 2014, is very techno-optimistic in every aspect of the society. The second (post-COVID pandemic) report [European Commission, 2021] from 2021 is slightly less optimistic and mentions vulnerabilities and disinformation. It also discusses sustainability, mentioning how digital technologies can contribute to EU Green Deal objectives. The third report [START_REF] Polona | EU cyber-resilience act[END_REF] gives short-term objectives regarding cyber-security after the beginning of the Russian-Ukrainian war. From this analysis, Andok highlights the shift from opportunities only to dangers and threats, and from 40 years perspective visions to shorter ones (10 years or even less).

METHODOLOGY

This section describes the 14 studies (section 3.2) we chose to analyze. We also present the features we use to classify them, which can influence on the evolution of ICT within the different scenarios (section 3.1).

Typologies describing the studies and scenarios

Each study has its way of designing possible futures, so capturing the diversity of the scenarios is complex [Van Notten et al., 2003]. Several works have proposed scenario typologies (e.g. [START_REF] Ducot | A typology for scenarios[END_REF], Van Notten et al., 2003, Crawford, 2019]) to capture this diversity. These typologies aim to categorize scenarios by answering the questions of why (project goal), how (process design), and what (scenario content) [Van Notten et al., 2003]. However, more analysis is needed to understand more deeply why scenarios end up being so similar or different. Scenarios result from hypotheses and parameters evolutions regarding economy, lifestyles and governance, which are not always explicit.

In this work, we focus on the place and role of ICT in future perspectives. We are therefore interested in comparing the different scenarios according to features that influence the place of ICT. Authors [START_REF] Erdmann | The future impact of icts on environmental sustainability[END_REF]Hilty, 2010] distinguish external variables that include GDP, population, labor demand, electricity prices, and other variables that may influence first-, second-, and third-order impacts of ICT. Examples of variables impacting first-order impacts are technological trends from large to small devices, household internet penetration, or energy efficiency. Variables for second-order impacts include energy efficiency or materials potentials for other sectors of activity. Finally, variables for third-order impacts are elasticity of demand, average personal transport time, or some economic behavior. The authors use all these variables to analyze the three scenarios from [START_REF] Erdmann | The future impact of icts on environmental sustainability[END_REF].

Following these works, we propose our own typology and variables to analyze ICT in prospective scenarios. We differentiate three levels of features to characterize every scenario (Table 1). The first one is the general typology from [Van Notten et al., 2003]. It enables to view how the study was conducted and its perimeter quickly. The second one is Societal variables, which concern hypotheses for society pathways regarding lifestyle, economy, governance, demography, and equality. We propose variables freely adapted from [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF]. When analyzing the scenarios, we observed that the variables of economic growth, sobriety, the importance of the state, and the collaboration between countries were discussed in all general studies and drive scenarios. We here refer to general studies as the ones that regard all areas of society. These societal variables impact the kind of ICT envisioned; for example, a scenario with solid states implies centralization of digital infrastructure and services.

Finally, we considered ICT-specific variables to characterize the ICT infrastructure and usage types. We distinguished three types of ICT-specific variables, the first being general ICT characteristics, with variables about the evolution of usages, about equipment (lifetimes, quantity of equipment, data center locations, use of cloud,...), and about usage (energy efficiency, data flows and data center consumption). All these characteristics directly impact equipment and infrastructures, and we call them infrastructure variables. The second type, called applications, addresses the kind of applications of ICT considered in the scenarios (teleworking, smart mobility, robots for manufacturing in industry,...), and the third type, technologies, the digital technologies present in the scenario (data analytics, AI, cloud and edge computing,...).

Even if digital technologies exist in all scenarios, the studies rarely mention these variables. We observed that they are only discussed explicitly in quantitative studies that calculate energy consumption and greenhouse gas emissions (e.g., [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], négaWatt, 2021[START_REF] Rte | Energy pathways to 2050[END_REF]) and in prospective studies specifically targetting ICT as main topic (e.g., [START_REF] Creutzig | Digitalization and the anthropocene[END_REF], CNIL, 2021, Deron and McDonald, 2022]). In fact, as previously observed by [START_REF] Creutzig | Digitalization and the anthropocene[END_REF], no current conceptualization of decarbonization pathways explicitly accounts for the impacts of digitalization in the Anthropocene.

Figure 3 gives the complete list of variables.

Studies selection

In this section, we present how we chose the 14 studies and how we categorized them according to a subset of features that we found to be relevant. We give a short overview of the considered studies in Appendix A. We also provide a complete classification of all scenarios according to the typology and variables described in the previous section in the supplementary material.

We first selected studies we already knew, then searched for others online. We tried to find studies with various: spatial perimeters (which countries are considered), domains considered (ICT -specific or not), and methodologies (narratives vs quantitative studies). Other variables, such as those of the typology (section 3.1), also help differentiate scenarios but were not our main starting points. The last criterion we used, which is not part of the typology from [Van Notten et al., 2003], is the publication year.

Publication year

We limited ourselves to recent studies. The oldest one in our deep analysis was published in 2018. We found very few notions of digital technologies in the oldest general scenarios. For example, in [OECD, 2011], we found only one mention of data access, smart metering, and a suggestion to make chemical information widely available through the Internet thanks to the development of new and innovative computer models. Another example of a scenario that we purposely did not include in this work is the ICT-specific from [START_REF] Erdmann | The future impact of icts on environmental sustainability[END_REF]. It aims to explore (qualitatively) and assess (quantitatively) how ICT will influence environmental sustainability between 2003 and 2020.

Spatial scale As we are located in France, we naturally started our review with the most recent prospective works made in this country: [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], négaWatt, 2021, Ministère de la Transition écologique et solidaire, 2020[START_REF] Rte | Energy pathways to 2050[END_REF], The Shift Project, 2020, Millot et al., 2018, CNIL, 2021]. We then opened to studies targeting the future of EU: [European Commission, 2019, European Environment Agency, 2021]. Finally, we selected studies for the entire world: [IPCC, 2022[START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], Danish Design Center, 2020, Creutzig et al., 2022]. One ICT-specific study focuses on Quebec [START_REF] Deron | Comment faire converger la transition numérique et la transition écologique au québec dans un horizon de 20 ans?[END_REF]. The studies chosen thus mostly target OECD countries, which is a limitation of our work.

Data With this criterion, we differentiate qualitative only from more quantitative studies. Within qualitative, we include some entirely narrative studies: [European Environment Agency, 2021[START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], Danish Design Center, 2020]. They include stories of people living in 2050 enabling us to look at what life could more concretely look like, and resemble science fiction. The study [Danish Design Center, 2020] is in the form of a future scenario toolkit. Many other toolkits2 exist but were not studied here as none are ICT-centered, and we considered these toolkits to be redundant with the ones already studied. Conversely, some studies are much more quantitative and try to estimate GHG emissions by 2050 (e.g., [START_REF] Rte | Energy pathways to 2050[END_REF] is mainly based on numerical models).

Topic All studies build upon climate change context. General prospective studies concern all societal areas (e.g. [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], IPCC, 2022, The Shift Project, 2020[START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF]. Additionally, we selected two studies focusing on energy in France in 2050 [START_REF] Rte | Energy pathways to 2050[END_REF], Millot et al., 2018]. Finally, obviously, we have included in our work studies that specifically target information and communication technologies: [START_REF] Creutzig | Digitalization and the anthropocene[END_REF], CNIL, 2021, Deron and McDonald, 2022].

RESULTS

We now present which digital technologies (section 4.1) can be found in prospective studies (section 4.2). All studies consider that ICT will be present in 2050 at different scales. In some scenarios, digital technologies are central in every aspect of society, but not in all of them. Here, we only present more frequent or surprising findings and refer the reader to supplementary material for complete details. Figure 2 presents a summary of our findings.

Digital technologies and ICT characteristics

Digital technologies that are the most present in scenarios are artificial intelligence (AI), robotics and automation, the Internet of Things (IoT), drones, and data analytics. Most studies explicitly mention AI and robotics for at least one scenario. On the opposite, virtual and mix reality for working remotely and leisure can only be read in the stories of some narrative scenarios. Remark that technologies are not always directly named; we can only assume that this technology is used in a given application. For example, precise agriculture might be mentioned as an application but with no mention of AI and robotics within the scenario. In the complete table given in the supplementary material, we have tried to avoid making our assumptions. A technology is marked as present in a scenario only if explicitly mentioned.

As a consequence of the use of data by digital technologies, 5 scenarios mention open data in four studies: (in studies [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF][START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], European Commission, 2019, Creutzig et al., 2022]). Open data is essential in the "Deliberate for the good" scenario of the ICT-specific study [START_REF] Creutzig | Digitalization and the anthropocene[END_REF]. It comes with the idea that sustainable ICT requires more equity and collective data management.

Concerning the environmental impacts of digital technologies, four scenarios specifically mention mandatory life-cycle assessments of all new services and equipment (in studies [START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], The Shift Project, 2020, European Commission, 2019, Deron and McDonald, 2022]).

Applications of digital technologies

As already said, digital technologies are present in every scenario we have read. Here, we present the applications for which these technologies are deployed. These applications are driven by general variables such as economic growth, demography, or lifestyles.

Note that scenarios are not entirely exhaustive regarding applications. It is not because an application is not explicitly mentioned that it does not exist in the future that is described. Similar to what we did for technologies, we avoided making assumptions about omissions in the paper and supplementary material.

Main applications

Almost all studies consider remote working, precise medicine and smart transports to be natural ICT applications. To a lesser extent, applications in farming, economy, and buildings are widely present. These applications are a natural extension of today's current development and funding of ICT.

ICT is also considered in several scenarios for ecological, economic, and social monitoring. In particular, it enables tracking the state of the planet for forecasting and information on extreme events.

Applications only discussed in a few scenarios

Some applications that already exist today are not discussed in all scenarios:

• e-commerce: We only saw e-commerce in four studies ( [The Shift Project, 2020[START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], Danish Design Center, 2020]) with an increase (in particular for business-as-usual scenarios) or a decrease (for more sober scenarios). Supply chain management is mentioned in [IPCC, 2022] but not specifically for e-commerce. • Social media: ICT is also still used for communication and social media and explicitly mentioned as such in the Regional Cooperations scenario of [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], in the Ecotopia and Technocracy scenarios of [European Environment Agency, 2021], and in [CNIL, 2021]. In these scenarios, digital technologies enable citizens to interact continuously.

• Leisure: Leisure relying on digital technologies is discussed in several studies, with different visions in different scenarios. In [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], the frugal scenario assumes less digital leisure, while the Restauration Gamble one assumes more and more digital leisure. Conversely, the [négaWatt, 2021] scenario, which is a relatively sober scenario, supposes that digitalization continues for leisure activities.

Even more surprising, the Ecotopia scenario of the study [European Environment Agency, 2021] scenario, which is, in essence, closer to nature, considers an increased presence of the digital sphere.

Digital technologies can also be used to improve the living environment, as in the Humans Inc. scenario of [START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], which mentions digital walls displaying images of a clean waterfront to protect residents from unpleasant views.

• Surveillance: In general studies, surveillance was only found in the Extinction express scenario of [START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF] with the use of micro-drones by the police and in centralized scenarios from [Danish Design Center, 2020], with AI or autonomous units. Naturally, it is discussed more deeply in [CNIL, 2021], the main topic being data protection and individual privacy. As such, data surveillance is a central variable of this study.

Furthermore, while digital technologies are widely used in scientific domains (e.g., biology or physics) today, they are only mentioned in one study.

Sobriety in digital technologies

Some scenarios call for sobriety and therefore, bring sobriety within the digital sector inherently. This is visible, for instance, in the sufficiency scenario of [START_REF] Rte | Energy pathways to 2050[END_REF] with less digital leisure and less digital advertising. In the Frugal Generation scenario from [START_REF] Ademe | Transition (s) 2050. choisir maintenant, agir pour le climat[END_REF], digital sobriety implies no new data center development and a stop of data growth. Another aspect of this sobriety concerns equipment repairability by users, which is discussed in many scenarios to increase equipment lifetime. In [START_REF] Deron | Comment faire converger la transition numérique et la transition écologique au québec dans un horizon de 20 ans?[END_REF], a reduction of the number of pieces of equipment is also possible with the development of equipment sharing in companies.

Some sober scenarios [négaWatt, 2021, The Shift Project, 2020] consider digital sobriety from a digital technologies usage angle. The proposal is to control usage and limit data flows. In the scenario from [The Shift Project, 2020], digital sobriety includes reducing video resolutions or cloud gaming, or bounding equipment rate per person. But, on the contrary, this same scenario assumes an increase in the use of ICT in many sectors (such as higher education or defense). [START_REF] Creutzig | Digitalization and the anthropocene[END_REF]propose an extensive application of ICT to match sustainable development goals.

DISCUSSIONS

The first observation of our survey was that there is no scenario little or no ICT. Due to the increasing environmental impacts of digital technologies [START_REF] Freitag | The real climate and transformative impact of ICT: A critique of estimates, trends, and regulations[END_REF], it is essential to think about their place in an environmentally-constrained world. The role of digitalization in the anthropocene was also the starting point of [START_REF] Creutzig | Digitalization and the anthropocene[END_REF]. In addition, ICT is related to significant physical, resilience, and environmental challenges that should drive its future developments.

In the following, we discuss how the studies considered these challenges and what is currently missing when considering ICT in prospective studies.

Lack of systemic view of ICT All scenarios admit a digital world quite similar to that of today. It can be more minimalistic or developed, sometimes with sobriety and efficiency, but no significant change exists. Many scenarios give a central place to IT for Green applications (smart farming, smart building, ecological monitoring). Some structural changes come from innovations in ICT, such as teleworking or autonomous driving.

As our goal was to study the place of digital technologies in future scenarios, we defined general ICT-specific variables to analyze if some scenarios consider them as the starting point. These variables encompass the growth of data, location of data centers, or sobriety usage. ICT variables (section 3.1) can be seen as parameters that can be changed to achieve different scenarios. They could indeed serve as central hypotheses to design general scenarios, i.e. being one of the causes in the scenario. An example is the following: because there will be much efficiency in digital technologies in the future, these technologies will be more deployed. Or, because of a limitation on the number of data centers, digital technologies have stopped being applied to some sectors of society. However, no general study has built upon these considerations. ICT variables remain only consequences of other aspects of these scenarios. While ICT-centered studies [START_REF] Creutzig | Digitalization and the anthropocene[END_REF], CNIL, 2021, Deron and McDonald, 2022] build upon these ICT variables, their scenarios hardly mention the application of ICT in various areas of society.

Scenarios rarely look at ICT with a comprehensive perspective. The studies often provide a citizen's point of view on ICT more than companies, organizations, or society one. Not having a more systemic view of society implies that ICT is very application-oriented, omitting all the interconnection with infrastructures and technologies. For example, [The Shift Project, 2020] offers a specific plan for the future of digital technologies, but separated from other sectors of activities and with few interactions. While digital sobriety is encouraged, ICT's place in other sectors is hardly discussed, even when it is already deployed.

Resilience and missing applications

In addition, ICT is related to significant physical, resilience, and environmental challenges: ICT infrastructures, for example, are very vulnerable to extreme climate events. This vulnerability is only very rarely evoked in the scenarios. Only [The Shift Project, 2020] states that "The ubiquity of digital technology makes its resilience crucial to many aspects of society", and this variable is absent from all scenarios. Not considering the interaction of digital technologies with other sectors of activities may lead to inconsistent scenarios. Furthermore, digital technologies are often seen as crucial for decarbonization. Its central place in some decarbonization strategies with regard to its vulnerability is never discussed.

Of course, it is difficult for a prospective study to cover all areas of society. Nevertheless, those that serve essential needs such as drinking, eating, housing, or health care might be the ones that are the most important to develop imaginaries and make the right decisions. Many of these essential areas already depend on ICT today. But no study mentions them all. We can think for example, about all supply chains or water supply and management. We can, therefore, only guess that these areas may also follow business-as-usual or sobriety tendencies. This lack of details raises questions regarding the transformations that an increase or decrease in digital technologies may imply for these applications and people working in these fields. No study questions the resilience of society towards these digital technologies.

Another aspect that is rarely tackled in scenarios is cybersecurity. Another aspect that scenarios rarely tackle is cybersecurity. The capacity of the technologies to resist cyber-attacks is essential, especially in scenarios with more fragmentation of the world.

Questions related to ICT materiality Developing ICT in many sectors of activities, as proposed in some scenarios, would likely necessitate the installation of a significant amount of new digital infrastructures. Only some scenarios mention the availability or criticity of resources, pure water, energy, or land (e.g., with resource colonies on the moon and deep sea mining in Extinction express of [START_REF] Arup | 2050 Scenarios: four plausible futures[END_REF], or in [START_REF] Rte | Energy pathways to 2050[END_REF] scenarios for energy production). This physical reality behind digital technologies is most often forgotten.

Relying on ICT in the future requires looking at energy and resources supply, which geopolitical tensions, collaborations between countries, or changes in governance may hinder. These tensions are discussed in French National studies (e.g. RTE and negaWatt) and in the narrative study Arup, but do not seem to influence their integration of ICT. The Extinction express scenario of the latter describes resource colonies on the moon and in the deep sea.

To the best of our knowledge, no study, however, mentions the geopolitical aspects related to the location of data centers and the installation of ICT infrastructures (e.g., underwater cables or satellites).

New technologies Surprisingly, many technologies that have started to receive attention and funding today are not mentioned in any of the studies, which build upon existing technologies only. For example, there is very little about 6G, and nothing on quantum informatics, intermittent computing, or DNA data storage. It is difficult to imagine how these innovations in ICT could be integrated in the scenarios. An example of studies where disruptive technologies (e.g., cyborg botany or olfactory notifications) are considered in scenarios has been presented by French designers3. Note that we did not include this work in our analysis because of a lack of details on the methodology. Significant changes in the use of technology, by using low-tech solutions for example, are also mostly absent from scenarios.

In [START_REF] Erdmann | Scenario analysis: exploring the macroeconomic impacts of information and communication technologies on greenhouse gas emissions[END_REF], the authors argued that forthcoming macroeconomic studies on ICT should account for first-, second-, and third-order effects, reflect error 3https://b-com.com/actualite/immersion-dans-le-numerique-responsable-de-2040 margins resulting from data uncertainty and use scenario techniques to explore future uncertainty. However, the studies we analyzed generally do not, even when ICT-centered. Some studies point to possible rebound effects of digital technologies, but indirect effects of ICT and their assessment are never included in the scenarios.

Disruption

In continuity with the previous point, very few general scenarios are peripheral, i.e., include unlikely and extreme events and consider a discontinuous path to the future. Generally, disruptive scenarios are narratives. When looking specifically at ICT in general scenarios, it is pretty similar to today's. Our relationship to digital technologies is not deeply questioned, which may be why ICT is present in all scenarios without breakthrough innovations.

Other environmental aspects

The studies were all made from a climate change perspective, omitting biodiversity losses and other planetary boundaries and focusing on human futures only without considering other species. These environmental problems may have other consequences on future scenarios. One that is directly related to ICT is water scarcity. Indeed, the manufacturing of ICT equipment and data center cooling have a substantial ecological footprint in terms of water use. Prospective studies on ICT should, therefore, broaden their narrations.

Global North centered Most innovations in the ICT sector and major industries of the domain are from Global North countries. As a consequence, the studies we have chosen were made in OECD countries, and this clearly has an influence on scenarios. Some studies (e.g., Arup) provide visions within the world and have been designed with people from several countries worldwide. Nevertheless, our work is more likely not representative of visions from Global South studies, and future works should consider how to imagine ICT for the future in Global South countries.

CONCLUSION

In this paper, we have analyzed the place of ICT in prospective scenarios. We have highlighted some variables that influence the development of digital technologies and the areas of applications where ICT might be essential in the future. Our analysis demonstrates that the feasibility and consequences of the increasing development of digital technologies are not sufficiently considered. Through our discussions, we have shown that the studies hardly question our relationships to digital technologies or the applications of ICT in the context of the Anthropocene. This shortcoming limits the possibility of imagining more diverse plausible futures for the ICT sector. There is, therefore, a need to design prospective studies that could offer this more diverse and systemic view of ICT and highlight which undone science [Hess, 2015] should receive more attention. Prospective studies with a sustainability perspective for ICT can i) offer a more diverse and systemic view of the future of digital technologies; ii) highlight the need for discussing, structuring, or funding. As an example, [START_REF] Deron | Comment faire converger la transition numérique et la transition écologique au québec dans un horizon de 20 ans?[END_REF] indeed demonstrate that, from prospective co-design workshops, it is possible to find milestones to reach a desirable future of digital technologies. The milestones show samples of undone sciences [Hess, 2015] for which social and industrial movements, funding, and research are needed for a desirable and sustainable ICT. Study made by an international multi-disciplinary team of consultants, designers and scientists. In the study, Climate considerations come third, subordinate to economic development and societal wellbeing. Scenarios are narratives and accompanied by a story told from the perspective of a person within that world, a timeline of events, and the achievement of the 17 UN SDGs.

A SUMMARY OF STUDIES REVIEWED FOR THIS PAPER

Greentocracy; Post Anthropocene; Extinction Express; Humans Inc. DDC 2020

The Danish Design Center (DDC) designed the Living Futures: Scenario Kit for understanding, discussing, and shaping the future. The kit is built around a set of four alternative futures set in the year 2050 explored through narrated stories by fictive people living in them. Centralised Market-driven;Centralised Society-driven;Distributed Market-driven;Distributed Society-driven . SNBC 2020 The National Low Carbon Strategy (SNBC) describes a roadmap for France on how to steer its climate change mitigation policy. The SNBC is based on a reference scenario developed through a modelling exercise also used in the Multi-annual Energy Programming. The scenario details the public policy measures, in addition to those already in place, which will allow France to meet its short-, medium-and long-term climate and energy objectives as best it can.

Baseline RTE 2022

Study on the technical conditions necessary for a power system with a High Share of Renewables in France Towards 2050, under the RCP 4.5 trajectory from IPCC 5th report. Baseline; Extensive Reindustrialisation; Sufficiency; Acceleration 2030 Shift 2020

The Shift Project published a plan for transforming French economy in 2022 for each sector of the economy. A preliminary report was published in end 2020 and this is the one we review here. The Université de Montréal and Espace pour la vie propose Chemins de transition ("Paths for transition"). This project combines a participative approach with major systemic challenges on a provincial scale. It combines different methodologies (backcasting, change-oriented approaches, transition management, etc.) and addresses 3 challenges: food, digital, territory. We here focus on digital challenge only.

Quebec 2040

Table 2: Summary of studies reviewed for this paper

Figure 1 :

 1 Figure 1: Each study may include several scenarios, representing alternative futures

  Figure 2: Summary of our scenario analysis for ICT. a),c),e): Number of scenarios among the 35 explicitly mentioning an ICT variable. b),d),f): Number of prospective studies among the 14 explicitly mentioning an ICT variable. For complete details, we refer the readers to our complementary material.

  models two contrasting lifestyles for France in 2072,to answer the question: To what extent do lifestyles influence the energy system's capacity to achieve carbon neutrality?; And amongs other, is a digital world compatible with the need to decarbonize the energy system, as usually thought? Digital society; Collective society D&A 2022 This Digitalization & Anthropocene research study presents the past, present, and future of digitalization. It presents three illustrative future pathways that span the possibility space for digitalization and decarbonization in the Anthropocene. The authors conclude by identifying leverage points that shift human-digital-Earth interactions toward sustainability Planetary destabilization;Green but inhumane; Deliberate for the good CNIL 2021 This study proposes new narratives and imaginaries regarding the protection of personal data in 2030 to help thinking regulatory practices. Throughout the process, highlights have been made on the use of technology in different social groups and at different times of digital life, as well as the resulting risks to individual and collective freedoms. Renowed; Meddling; Home Sour Home Digit. Challenge 2022

Table 1 :

 1 Overview of typology and parametric variables used to compare scenarios

		Level:	Study
	Typology	Objective: Features overview:	General overview of the study Project goal, content and complexity
		Reference:	[Van Notten et al., 2003]
		Level:	Scenario
	Societal variables	Objective:	non ICT-specific variables that influence scenarios
		Features overview:	Economy, lifestyle, demography, governance
		Level	Scenario
	ICT variables	Objective Features overview	ICT-specific variables present in scenarios Infrastructure, Applications, Technologies

2https://oecd-opsi.org/toolkits/?_toolkit_discipline_or_practice= futures-and-foresight

B SCENARIO VARIABLES