Multivariate sensitivity analysis for a large-scale climate impact and adaptation model

We develop a new efficient methodology for Bayesian global sensitivity analysis for large-scale multivariate data. The focus is on computationally demanding models with correlated variables. A multivariate Gaussian process is used as a surrogate model to replace the expensive computer model. To improve the computational efficiency and performance of the model, compactly supported correlation functions are used. The goal is to generate sparse matrices, which give crucial advantages when dealing with large datasets, where we use cross-validation to determine the optimal degree of sparsity. This method was combined with a robust adaptive Metropolis algorithm coupled with a parallel implementation to speed up the convergence to the target distribution. The method was applied to a multivariate dataset from the IMPRESSIONS Integrated Assessment Platform (IAP2), an extension of the CLIMSAVE IAP, which has been widely applied in climate change impact, adaptation and vulnerability assessments. Our empirical results on synthetic and IAP2 data show that the proposed methods are efficient and accurate for global sensitivity analysis of complex models

Differences between low-end and high-end climate change impacts in Europe across multiple sectors

The Paris Agreement established the 1.5 and 2 °C targets based on the recognition “that this would significantly reduce the risks and impacts of climate change”. We tested this assertion by comparing impacts at the regional scale between low-end ( 4 °C; RCP8.5) climate change scenarios accounting for interactions across six sectors (agriculture, forestry, biodiversity, water, coasts and urban) using an integrated assessment model. Results show that there are only minor differences in most impact indicators for the 2020s time slice, but impacts are considerably greater under high-end than low-end climate change in the 2050s and 2080s. For example, for the 2080s, mitigation consistent with the Paris Agreement would reduce aggregate Europe-wide impacts on the area of intensive agriculture by 21% (on average across climate models), on the area of managed forests by 34%, on water stress by 14%, on people flooded by 10% and on biodiversity vulnerability by 16%. Including socio-economic scenarios (SSPs 1, 3, 4, 5) results in considerably greater variation in the magnitude, range and direction of change of the majority of impact indicators than climate change alone. In particular, socio-economic factors much more strongly drive changes in land use and food production than changes in climate, sometimes overriding the differences due to low-end and high-end climate change. Such impacts pose significant challenges for adaptation and highlight the importance of searching for synergies between adaptation and mitigation and linking them to sustainable development goals

Future projections of biodiversity and ecosystem services in Europe with two integrated assessment models

Projections of future changes in biodiversity and ecosystem services (BES) are of increasing importance to inform policy and decision-making on options for conservation and sustainable use of BES. Scenario-based modelling is a powerful tool to assess these future changes. This study assesses the consequences for BES in Europe under four socio-environmental scenarios designed from a BES perspective. We evaluated these scenarios using two integrated assessment models (IMAGE-GLOBIO and CLIMSAVE IAP, respectively). Our results showed that (i) climate and land use change will continue to pose significant threats to biodiversity and some ecosystem services, even in the most optimistic scenario; (ii) none of the four scenarios achieved overall preservation of BES in Europe; and (iii) targeted policies (e.g. on climate change, biodiversity conservation and sustainable land management) and behavioural change (e.g. reducing meat consumption, water-saving behaviour) reduced the magnitude of BES loss. These findings stress the necessity of more ambitious policies and actions if BES in Europe are to be safeguarded. We further found that the multi-modelling approach was critical to account for complementary BES dimensions and highlighted different sources of uncertainties (e.g. related to land use allocation, driving forces behind BES changes, trade assumptions), which facilitated nuanced and contextualised insights with respect to possible BES futures

Advancing the use of scenarios to understand society’s capacity to achieve the 1.5 degree target

With a range of potential pathways to a sustainable future compatible with the Paris Agreement 1.5 °C target, scenario analysis has emerged as a key tool in studies of climate change mitigation and adaptation. A wide range of alternative scenarios have been created, and core amongst these are five socio-economic scenarios (Shared Socio-economic Pathways or SSPs) and four emission scenarios (Representative Concentration Pathways or RCPs). Whilst mitigation scenarios (the Shared Policy Assumptions, or SPAs) have been developed for each SSP-RCP combination, describing the actions necessary to match the climate pathway of the RCP, there has not yet been a systematic approach to address whether and how these actions can be enabled in practice. We present a novel and transferable framework to understand society’s capacity to achieve the 1.5 °C target, based on four participatory case studies using the SSP-RCP scenarios. The methodology builds on a framework for categorising different types of societal capitals and capacities and assessing their impact on the potential to implement different types of mitigation actions. All four case studies show that SSP1 has the highest potential to reach the target. Although environmental awareness is high in both SSP1 and SSP4, continued social inequalities in SSP4 restrict society’s capacity to transform, despite economic growth. In the two least environmentally-aware SSPs, SSP3 and SSP5, the transformation potential is low, but the view on capitals and capacities nonetheless helps identify opportunities for actors to develop and implement mitigation actions. The study highlights that techno-economic assessments of climate strategies need to be complemented by consideration of the critical role played by social and human capital, and by societal capacity to mobilise and create these capitals despite different socio-economic trends. These capitals and capacities are essential to enable the rapid innovation, behavioural change and international co-ordination needed to achieve the 1.5 °C target

Combining policy analyses, exploratory scenarios, and integrated modelling to assess land use policy options

Scenario-based approaches provide decision makers with accessible storylines of potential future changes. The parameterisation of such storylines as input variables for integrated assessment models allows using models as a test bed for assessing the effects of alternative land use policy options in different scenarios. However, the potential of this kind of policy-screening analysis can be further improved by assessing the institutional compatibility of the policy options under review. The aim of this paper is to explore the added value of combining institutions-oriented policy analyses with scenario-modelling approaches for improved assessments of EU land use policy options. We describe an expert-based, stepwise process to combine four scenario storylines and two integrated assessment model approaches (CLIMSAVE & IMAGE-GLOBIO) with a procedure for institutional compatibility assessment. Among the subsidies we assessed were those for technology-driven intensification of agricultural production, which would contribute to decreasing demand for cropland across a range of scenarios. In regionalised policy designs, they also contribute to ecological effectiveness, and higher costs of governing. Subsidies to promote biomass production can have negative effects on ecosystems including land conversion, conversion of grassland into cropland as well as conversion of natural forests into managed forests. These effects can to some extent be mitigated by careful policy design which considers the institutional context and features cross-sectoral coordination. An integrated Ecosystem Services Framework policy could accommodate regionalised policy designs and cross-sectoral coordination, however, it can operate only under specific circumstances and needs particular efforts. Rural development approaches are another alternative which feature expansion of cropland by means of a large-scale, bottom-up transformation based on voluntary changes in behaviour, flexibility, participation, and local and regional collaboration. Apart from a vast number of interdisciplinary lessons learned, we also gained insights from the science-policy interface. A weak EU appeared as a plausible scenario from a scientific perspective, given the current political environment. However, it appreaded to be unacceptable at EU level policy making. We decided to maintain scientific independence and looked at policy options also in the context of a weak EU yielding environmentally beneficial opportunities for regional decision making at the expense of relevance of our scenarios to EU level policy makers

Selecting methods for ecosystem service assessment: a decision tree approach

A range of methods are available for assessing ecosystem services. Methods differ in their aims; from mapping and modelling the supply and demand of ecosystem services to appraising their economic and non-economic importance through valuation techniques. Comprehensive guidance for the selection of appropriate ecosystem service assessment methods that address the requirements of different decision-making contexts is lacking. This paper tackles this gap using the experience from 27 case studies which applied different biophysical, socio-cultural and monetary valuation methods to operationalise the ecosystem service concept towards sustainable land, water and urban management. A survey of the reasons why the case study teams selected particular methods revealed that stakeholder-oriented reasons, such as stakeholder participation, inclusion of local knowledge and ease of communication, and decision-oriented reasons, such as the purpose of the case study and the ecosystem services at stake, were key considerations in selecting a method. Pragmatic reasons such as available data, resources and expertise were also important factors. This information was used to develop a set of linked decision trees, which aim to provide guidance to researchers and practitioners in choosing ecosystem service assessment methods that are suitable for their context

New EU-scale environmental scenarios until 2050 – scenario process and initial scenario applications

Understanding uncertainties and risks can be considered to be the main motivation behind environmental scenario studies to assess potential economic, environmental, social or technical developments and their expected consequences for society and environment. The scenario study presented in this paper was designed to contribute to the question of how natural capital and ecosystem services may evolve in Europe under different socio-environmental conditions. The study was conducted as part of OpenNESS, an on-going EU FP7 research project. We present the iterative participatory scenario process, the storylines and drivers, examples for regional applications, as well as initial feedback from stakeholders. In a participatory iterative approach four scenarios were developed for the period to 2050, involving regional and EU-level users and stakeholders. Subsequently, scenarios were successfully contextualised and applied in regional place-based studies under widely differing socio-environmental conditions. Regional teams used different approaches to adapt storylines and drivers to the regional contexts. In an internal evaluation process among regional stakeholders some participants expressed concerns about the scenario method. Suggestions are made how to overcome these limitations. However, most participants approved the scenario method, especially in terms of provoking discussions, and confirmed the usefulness and applicability of the approach

(Dis) integrated valuation - Assessing the information gaps in ecosystem service appraisals for governance support

The operational challenges of integrated ecosystem service (ES) appraisals are determined by study purpose, system complexity and uncertainty, decision-makers' requirements for reliability and accuracy of methods, and approaches to stakeholder-science interaction in different decision contexts. To explore these factors we defined an information gap hypothesis, based on a theory of cumulative uncertainty in ES appraisals. When decision context requirements for accuracy and reliability increase, and the expected uncertainty of the ES appraisal methods also increases, the likelihood of methods being used is expected to drop, creating a potential information gap in governance. In order to test this information gap hypothesis, we evaluate 26 case studies and 80 ecosystem services appraisals in a large integrated EU research project. We find some support for a decreasing likelihood of ES appraisal methods coinciding with increasing accuracy and reliability requirements of the decision-support context, and with increasing uncertainty. We do not find that information costs are the explanation for this information gap, but rather that the research project interacted mostly with stakeholders outside the most decision-relevant contexts. The paper discusses how alternative definitions of integrated valuation can lead to different interpretations of decision-support information, and different governance approaches to dealing with uncertainty. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Integrating methods for ecosystem service assessment: Experiences from real world situations

The Ecosystem Services (ES) concept highlights the varied contributions the environment provides to humans and there are a wide range of methods/tools available to assess ES. However, in real-world decision contexts a single tool is rarely sufficient and methods must be combined to meet practitioner needs. Here, results from the OpenNESS project are presented to illustrate the methods selected to meet the needs of 24 real-world case studies and better understand why and how methods are combined to meet practical needs. Results showed that within the cases methods were combined to: i) address a range of ES; ii) assess both supply and demand of ES; iii) assess a range of value types; iv) reach different stake-holder groups v) cover weaknesses in other methods used and vi) to meet specific decision context needs. Methods were linked in a variety of ways: i) as input-output chains of methods; ii) through learning; iii) through method development and iv) through comparison/triangulation of results. The paper synthesises these case study-based experiences to provide insight to others working in practical contexts as to where, and in what contexts, different methods can be combined and how this can add value to case study analyses. (C) 2017 Published by Elsevier B.V.Peer reviewe