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International audience; When modelling medium and long-term challenges we need a reference path of economic development (the so-called baseline). Because sectoral models often offer a more fundamental understanding of future developments for specific sectors, many CGE modeling teams have adopted different kinds of linking approaches to sectoral models to generate baselines. We systematically compare and discuss approaches of linking CGE models for the baseline calibration procedure, and discuss best practices and pitfalls. We identify different types of linking approaches which we divide into a) links with partial equilibrium models, and b) links with non-economic models. These two types of linking approaches are then analyzed with respect to e.g. the degree of linkage, information exchanged, as well as compromises in aggregations and definitions. Based on this, we discuss potential drawbacks and conclude with suggestions for best practices and research recommendations.

Half of the European Union (EU) land and the livelihood of 10 million farmers is threatened by unsustainable land-use intensification, land abandonment and climate change. Policy instruments, including the EU Common Agricultural Policy (CAP) have so far failed to stop this environmental degradation. BESTMAP will: 1) Develop a behavioural theoretical modelling framework to take into account complexity of farmers’ decision-making; 2) Develop, adapt and customize a suite of opensource, flexible, interoperable and customisable computer models linked to existing data e.g. LPIS/IACS and remote sensing e.g. Sentinel-2; 3) Link economic, individual-farm agent-based, biophysical ecosystem services and biodiversity and geostatistical socio-economic models; 4) Produce a simple-to-use dashboard to compare scenarios of Agri-Environmental Schemes adoption; 5) Improve the effectiveness of future EU rural policies’ design, monitoring and implementation.

The replacement of fossil resources with renewable biomass in a bioeconomy is seen as a major contribution to climate change mitigation. This transformation will affect all members of society, making it crucial to consider the views of different stakeholders to ensure a socially acceptable transition towards a sustainable bioeconomy. To explore potential outcomes of bioeconomy strategies assuming different future pathways, a scenario analysis is a tool to inform decision-makers about policy impacts and trade-offs. The inter- and transdisciplinary research project “BioNex – The future of the biomass nexus” is the first project to develop bioeconomy scenarios together with stakeholders from politics, industry, and civil society in an iterative co-design process. As a result, three storylines describing diverging potential global futures are developed and quantified: Towards sustainability, business as usual, and towards resource depletion. The futures are driven by different assumptions on climate policy, cropland expansion, productivity growth in agriculture, prices of fossil energy, and consumption behaviour. Additionally, in the co-design process, three bioeconomy policies are developed: policy as usual, stronger development of the bioeconomy, and no policies. Besides presenting the results of the stakeholder workshops, this paper evaluates the strengths and shortcomings of a stakeholder approach in terms of policy-oriented research. According to the experience made within this study, it provides valuable insights for researchers and funding authorities they can use to optimise the employment of stakeholder-based research approaches.

Water sustainability is central to modern political and academic debates. Despite increasing efforts to promote regional and global integrated water management, climate change, population, and economic growth, and increasing consumption of water-intensive goods project higher water deficiency. Robust economic analyses rely on information about water supply and consumption across different production sectors, type of procurement source (public or private water supply), and water prices. Nevertheless, developing current and future economic water assessments and indicators is impeded by the absence of data. Despite the lack of official national statistics on water withdrawal and consumption, a small number of international and global databases have been constructed and attempt to combine available national water information into databases. Water databases do not commonly define and/or distinguish terms such as water use, water consumption, water supply, or water abstraction, and the associated aspects of water scarcity and sustainability. They comprise variable data quality, provided by numerous sources, and estimated values. This paper evaluates the current state of knowledge of national statistics, international and global water databases. We describe the data collection methods, identify basic concepts and definitions of water terms, followed by the criteria of consistent water databases. We inform about data availability across regions, and present the data content and definitions of national, international, and global water databases. The results show inconsistencies of data content and definitions, suggesting no evidence of data harmonization among databases. Therefore, our study cautions researchers to be careful when manipulating and comparing the available water data, especially when deriving policy recommendations or economic conclusions. In the long run, the headway of water research and political assessments depend on political enforcements to refine the meaningfulness of water data and support water collection, reporting, and monitoring. Alternatively, in the short- and medium-run, water data challenges can be addressed by joint research efforts for water data harmonization.

The pressure on land resources continuously increases not only with the rising demand for agricultural commodities, but also with the growing need for action on global challenges, such as biodiversity loss or climate change, where land plays a crucial role. Land saving as a strategy, where agricultural productivity is increased to allow a reduction of required cropland while sustaining production volumes and meeting demand, could address this trade-off. With our interdisciplinary model-based study, we globally assess regional potentials of land saving and analyze resulting effects on agricultural production, prices and trade. Thereby, different land saving strategies are investigated that (1) minimize required cropland (2) minimize spatial marginalization induced by land saving and (3) maximize the attainable profit. We find that current cropland requirements could be reduced between 37% and 48%, depending on the applied land saving strategy. The generally more efficient use of land would cause crop prices to fall in all regions, but also trigger an increase in global agricultural production of 2.8%. While largest land saving potentials occur in regions with high yield gaps, the impacts on prices and production are strongest in highly populated regions with already high pressure on land. Global crop prices and trade affect regional impacts of land saving on agricultural markets and can displace effects to spatially distant regions. Our results point out the importance of investigating the potentials and effects of land saving in the context of global markets within an integrative, global framework. The resulting land saving potentials can moreover reframe debates on global potentials for afforestation and carbon sequestration, as well as on how to reconcile agricultural production and biodiversity conservation and thus contribute to approaching central goals of the 21st century, addressed for example in the Sustainable Development Goals, the Paris Agreement or the post-2020 global biodiversity framework.

Mitigation of CO2 emissions is a global public good that imposes different regional economic costs. We assess the distributional effects of cooperative versus non-cooperative CO2 markets to fulfil the Nationally Determined Contributions (NDCs), considering different CO2 permit allocation rules in cooperative markets. We employ a global computable general equilibrium model based on the GTAP-9 database and the add-on GTAP-Power database. Our results show the resulting winners and losers under different policy scenarios with different permit allocation rules. We see that in 2030, we can obtain gains as high as $106 billion from global cooperation in CO2 markets. A cooperative CO2 permit market with equal per capita allowances results in considerable monetary transfers from high per capita emission regions to low per capita emission regions. In per capita terms, these transfers are comparable to the Official Development Assistance (ODA) transfers. We also disaggregate the mitigation costs into direct and indirect shares. For the energy-exporting regions, the largest cost component is unambiguously the indirect mitigation costs.

The ambitious climate policy objectives of the COP21 agreement require the design and the implementation of effective and efficient policy instruments. The effectiveness and efficiency of agricultural abatement options depend on regional climate and natural conditions, changes in the global economy, global agricultural markets and regional agricultural production. Thus, the assessment of abatement options requires consideration of the global scale, the market scale and the regional producer scale. We investigate two abatement options discussed controversially in literature. Both have been partially applied to reduce environmental pollution from agriculture: a tax on nitrogen and the obligatory set-aside of agricultural land. Our study provides an assessment of the ecological effectiveness and the economic efficiency of both abatement options under different global scenarios. In our policy analysis we combine three applied policy simulation models to develop an integrated economic model framework. This model framework considers the global, the national and the regional scale and consists of the global general equilibrium model DART-BIO, the partial-equilibrium model CAPRI and the regional supply model RAUMIS. In the different global scenarios, the results show that both abatement options create relatively high marginal abatement costs and that the maximally reached abated greenhouse gas emissions represent only 15% of the quantity required to fulfill the policy targets. Compared to the obligatory set-aside option, the nitrogen tax is in both scenarios the more efficient policy. With respect to impacts on production and environment, a nitrogen tax is less forecastable than the obligatory set-aside option. Our study illustrates the relevance of considering global economic and market change in the assessment of producer-targeting environmental policies.

At the European national and subnational levels exists a multitude of laws and programmes for the promotion of renewable energies. Taking Germany’s energy transition as an example, the most important regulations for the electricity, heat and transport fuel markets are the Renewable Energy Sources Act (EEG), the Renewable Energies Heat Act (EEWarmeG), the Law on Cogeneration of Heat and Power (KWKG), the Energy Tax Law and the Biofuel Quota Act. In addition to market incentives directly linked to the renewable energy markets, the electricity and heating sector is influenced by the regulations of the European Union Emissions Trading System (EU ETS). Comments on these support programmes and targets range from scathing to praising. We argue that a fundamental reform of the support system for renewable energies in Germany is required if the largest possible contribution to climate mitigation is to be achieved at the lowest possible cost. We show how such a support system could be designed in practice. Since the support system for renewables in Germany is not independent from European climate policies, we discuss possible support systems under the assumption that the EU ETS remains in place.

With rising demand for biomass, cropland expansion and intensification represent the main strategies to boost agricultural production, but are also major drivers of biodiversity decline. We investigate the consequences of attaining equal global production gains by 2030, either by cropland expansion or intensification, and analyse their impacts on agricultural markets and biodiversity. We find that both scenarios lead to lower crop prices across the world, even in regions where production decreases. Cropland expansion mostly affects biodiversity hotspots in Central and South America, while cropland intensification threatens biodiversity especially in Sub-Saharan Africa, India and China. Our results suggest that production gains will occur at the costs of biodiversity predominantly in developing tropical regions, while Europe and North America benefit from lower world market prices without putting their own biodiversity at risk. By identifying hotspots of potential future conflicts, we demonstrate where conservation prioritization is needed to balance agricultural production with conservation goals., The increase in needs for agricultural commodities is projected to outpace the growth of farmland production globally, leading to high pressure on farming systems in the next decades. Here, the authors investigate the future impact of cropland expansion and intensification on agricultural markets and biodiversity, and suggest the need for balancing agricultural production with conservation goals.

Potential trade-offs between providing sufficient food for a growing human population in the future and sustaining ecosystems and their services are driven by various biophysical and socio-economic parameters at different scales. In this study, we investigate these trade-offs by using a three-step interdisciplinary approach. We examine (1) how the expected global cropland expansion might affect food security in terms of agricultural production and prices, (2) where natural conditions are suitable for cropland expansion under changing climate conditions, and (3) whether this potential conversion to cropland would affect areas of high biodiversity value or conservation importance. Our results show that on the one hand, allowing the expansion of cropland generally results in an improved food security not only in regions where crop production rises, but also in net importing countries such as India and China. On the other hand, the estimated cropland expansion could take place in many highly biodiverse regions, pointing out the need for spatially detailed and context-specific assessments to understand the possible outcomes of different food security strategies. Our multidisciplinary approach is relevant with respect to the Sustainable Development Goals for implementing and enforcing sustainable pathways for increasing agricultural production, and ensuring food security while conserving biodiversity and ecosystem services. peerReviewed

Growing demand for meat and dairy products (MDP), biofuels, and scarcity of agricultural land are drivers of global land use competition. Impacts of policies targeting demand for MDP or biofuels have only been analysed separately. We use the computable general equilibrium model DART-BIO to investigate combined effects, since MDP and biofuel production are closely related via feestock use and co-production of animal feed. We implement four scenarios: (a) a baseline scenario; (b) halving MDP consumption in industrialised countries by a tax; (c) abolishing current biofuel policies; and (d) no exogenous land use change. We find that a MDP tax and exogenous land use change have larger effects on land use and food markets than biofuel policies. International trade is affected in all scenarios. With respect to combined effects of a MDP tax and biofuel policies, we find decreasing biodiesel but increasing bioethanol production. In addition, the MDP tax decreases the impact of biofuel policies on agricultural markets and land use. Our results highlight the importance of a detailed representation of different vegetable oils used in biodiesel production and related by-products. Finally, since the MDP tax increases the use of fossil fuels, the net climate mitigation potentials of such a tax should be investigated further.

The production of bioenergy is considered to be a promising energy source for a sustainable energy mix and it is politically promoted in many countries. With the exception of Brazilian ethanol, bioenergy is not competitive with fossil energy sources, and therefore needs to be subsidised. Several types of bioenergy are based on bulky raw biomass with high per unit transport costs, importantly impacting on the plant's production costs and profitability. In addition, considerable quantities of digestates are released, causing disposal costs. Various studies in the past aimed primarily at analysing transport costs of inputs. In this paper we focus on disposal costs of fermentation digestates from biogas production in Germany and analyse different processing techniques and their impact on profitability for three plant size in three case study areas. Our results show that especially in regions with only a small amount of agricultural land and a large heterogeneity in its agricultural area, processing of digestates increases the profitability of biogas production. The same accounts for regions with high livestock density, where the area needed for disposal is comparatively large. The cost efficiency is enforced by a high share of animal excrements on input and the biogas plant size.

Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification., Global demand for agricultural biomass is expected to exceed potential supply over the next few decades. Here, Mauser et al. show that by improving the management and efficiency of farmlands, global biomass has the potential to substantially exceed these estimates without the need for cropland expansion.

Taking Brazilian bioethanol as an example, this paper presents possible sustainability criteria for a certification scheme aimed to minimize negative socio-ecological impacts and to increase the sustainable production of biomass. We describe the methods that have led us to the identification of a first set of feasible sustainability criteria for Brazilian bioethanol and discuss issues to be considered when developing certification schemes for sustainability. General problems of a certification scheme lie in the inherent danger of introducing new non-tariff trade barriers and in the problems of including important higher scale issues like land conversion and food security. A certification system cannot replace a thorough analysis of policy impacts on sustainability issues.

Fil: Chisari, Omar Osvaldo. Universidad Argentina de la Empresa; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

The Renewable Energy Source Act (EEG) promotes German biogas production in order to substitute fossil fuels, protect the environment, and prevent climate change. As a consequence, green maize production has increased significantly over the last years, causing negative environmental effects on soil, water and biodiversity. In this paper we quantitatively analyse the EEG-reform in 2012 by applying the simulation tool ReSI-M (Regionalised Location Information System – Maize). Comparing the EEG 2012 with a former version of the legislation, results imply that the reform contributes to an expansion of biogas electricity generation compared to former versions, and thus to substitution of fossil fuels. Furthermore, given a restriction in the share of green maize input, its production is reduced and the crop-mix is diversified. However, since maize provides the highest energy output per area, total land requirement for biogas production increases. An alternative analysis shows that an EEG with tariffs independent from plant-types would provide the highest subsidy-efficiency, but slightly lower land efficiency compared to the EEG 2012

The production of bioenergy is considered to be a promising energy source for a sustainable energy mix and it is politically promoted in many countries. With the exception of Brazilian ethanol, bioenergy not competitive to fossil energy sources, and therefore needs to be subsidised. Several types of bioenergy are based on bulky raw biomass with high per unit transport costs, importantly impacting on the plant’s production costs and profitability. In addition, considerable quantities of digestates are released, causing disposal costs. Various studies in the past aimed primarily at analysing transport costs of inputs. In this paper we focus on disposal costs of fermentation digestates from biogas production in Germany and analyse different processing techniques and their impact on profitability for three plant size in three case study areas. Our results show that especially in regions with only a small amount of agricultural land and a large heterogeneity in its agricultural area, processing of digestates increases the profitability of biogas production. The same accounts for regions with high livestock density, where the area needed for disposal is comparatively large. The cost efficiency is enforced by a high share of animal excrements on input and the biogas plant size

The Renewable-Energy-Source-Act (EEG) promotes German biogas production in order to substitute fossil fuels, protect the environment and prevent climate change. In this paper we quantitatively analyse the EEG-reform in 2008. Results imply that the reform contributes to an expansion of biogas electricity generation and thus to substitution of fossil fuels. However, subsidies, land and transport emissions per unit of electricity produced increase. An alternative analysis shows that an EEG with tariffs independent from plant-types would provide the highest subsidy-efficiency, lower land requirements and higher transport emissions compared to EEG before its reformation. Zusammenfassung: Biogasproduktion wird in Deutschland mit dem Ziel des Klima- und Umweltschutzes sowie der Substitution fossiler Energietrager durch das Erneuerbare-Energien-Gesetz (EEG) gefordert. Dieser Beitrag analysiert quantitativ durch Kopplung eines Agrarsektor- und eines Standortmodells die Novellierung des EEGs in 2008. Die Ergebnisse zeigen, dass die Novellierung durch einen verstarkten Ausbau der Energieerzeugung durch Biogas zur weiteren Substitution fossiler Energietrager beitragt, allerdings auch zu hoheren Kosten pro erzeugter Einheit Strom. Die Flacheneffizienz sinkt, wahrend Transportemissionen ansteigen. Eine alternativ untersuchte Ausgestaltung einer anlageunabhangigen Vergutung im EEG zeigt die hochste Subventionseffizienz, bei allerdings niedrigerer Flacheneffizienz und hoheren Transportemissionen im Vergleich zum EEG vor der Novellierung.

The location of first generation processing plants for biogas using bulky inputs is a prominent example of locational decisions of plants that face high per unit transport costs of feedstock and simultaneously depend to a large extent on feedstock availability. Modelling the resulting regional feedstock markets then requires a spatially explicit representation of demand. With production capacities of plants small in comparison to market size, large numbers of possible type-location combinations need to be considered, requiring considerable computation time under existing integer programming-based approaches. Therefore, in this paper we aim to present an alternative, faster and more flexible iterative solution approach to simulate location decisions for processing plants. And with greater flexibility, this approach is able to take into account spatially heterogeneous transport costs depending on total demand. The approach is implemented in a modelling framework for biogas production from green maize in Germany, which currently accounts for ca. five per cent of Germany's agricultural area. By modifying green maize prices, demand functions are derived and intersected with regional supply functions from an agricultural model to simulate market clearing prices and quantities. The application illustrates that our approach efficiently simulates markets characterised by small-scale demand units and high, spatially heterogeneous transport costs.

In the context of energy security and climate protection, biomass is given high importance. Nevertheless, land-use conflicts resulting from the cultivation of biomass and their economy-wide effects are yet to be fully understood. To shed light on this issue we link three distinctive models; a global, multi-regional general equilibrium model (DART), a regionalised agricultural sector model for Germany (RAUMIS) and a location model for biogas plants. The DART model allows capturing international and national feedback effects of an increased use of bioenergy such as increased agricultural prices. The interaction of DART and RAUMIS links global markets and connects them to the detailed specification of agricultural land use in Germany. Finally, we link this system to the newly developed location model ReSI-M that accounts for the location choices of biogas plants in Germany and the resulting regional markets for energy crop demand. As a first application of the modelling system we analyse the effects of the German Renewable Energy Source Act on German biogas production and of the EU 10%-biofuel target on German agriculture and world agricultural prices. A main result of the simulations is that accounting for existing land-use restrictions and land-use competition has a significant effect on model results

Landnutzungskonkurrenz und Landknappheit beeinflussen die Auswirkungen einer vermehrten Bioenergienutzung. Die ökonomischen Effekte der aktuellen Bioenergiepolitik sind ein entscheidender Faktor für die Konkurrenz um Landnutzung.

International audience; Modelling and projecting consumption, investment and government demand by detailed commodities in CGE models poses many data and methodological challenges. We review the state of knowledge of modelling consumption of commodities (price and income elasticities and demographics), as well as the historical trends that we should be able to explain. We then discuss the current approaches taken in CGE models to project the trends in demand at various levels of commodity disaggregation. We examine the pros and cons of the various approaches to adjust parameters over time or using functions of time and suggest a research agenda to improve modelling and projection. We compare projections out to 2050 using LES, CES and AIDADS functions in the same CGE model to illustrate the size of the differences. In addition, we briefly discuss the allocation of total investment and government demand to individual commodities.