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

Integrated assessment and valuation of ecosystem services - Guidelines and experiences

EU FP7 OpenNESS project deliverable D33 & D4

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

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

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

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