Investigating afforestation and bioenergy CCS as climate change mitigation strategies

The land-use sector can contribute to climate change mitigation not only by reducing greenhouse gas (GHG) emissions, but also by increasing carbon uptake from the atmosphere and thereby creating negative CO2 emissions. In this paper, we investigate two land-based climate change mitigation strategies for carbon removal: (1) afforestation and (2) bioenergy in combination with carbon capture and storage technology (bioenergy CCS). In our approach, a global tax on GHG emissions aimed at ambitious climate change mitigation incentivizes land-based mitigation by penalizing positive and rewarding negative CO2 emissions from the land-use system. We analyze afforestation and bioenergy CCS as standalone and combined mitigation strategies. We find that afforestation is a cost-efficient strategy for carbon removal at relatively low carbon prices, while bioenergy CCS becomes competitive only at higher prices. According to our results, cumulative carbon removal due to afforestation and bioenergy CCS is similar at the end of 21st century (600–700 GtCO2), while land-demand for afforestation is much higher compared to bioenergy CCS. In the combined setting, we identify competition for land, but the impact on the mitigation potential (1000 GtCO2) is partially alleviated by productivity increases in the agricultural sector. Moreover, our results indicate that early-century afforestation presumably will not negatively impact carbon removal due to bioenergy CCS in the second half of the 21st century. A sensitivity analysis shows that land-based mitigation is very sensitive to different levels of GHG taxes. Besides that, the mitigation potential of bioenergy CCS highly depends on the development of future bioenergy yields and the availability of geological carbon storage, while for afforestation projects the length of the crediting period is crucial

Investigating afforestation and bioenergy CCS as climate change mitigation strategies

The land-use sector can contribute to climate change mitigation not only by reducing greenhouse gas (GHG) emissions, but also by increasing carbon uptake from the atmosphere and thereby creating negative CO2 emissions. In this paper, we investigate two land-based climate change mitigation strategies for carbon removal: (1) afforestation and (2) bioenergy in combination with carbon capture and storage technology (bioenergy CCS). In our approach, a global tax on GHG emissions aimed at ambitious climate change mitigation incentivizes land-based mitigation by penalizing positive and rewarding negative CO2 emissions from the land-use system. We analyze afforestation and bioenergy CCS as standalone and combined mitigation strategies. We find that afforestation is a cost-efficient strategy for carbon removal at relatively low carbon prices, while bioenergy CCS becomes competitive only at higher prices. According to our results, cumulative carbon removal due to afforestation and bioenergy CCS is similar at the end of 21st century (600–700 GtCO2), while land-demand for afforestation is much higher compared to bioenergy CCS. In the combined setting, we identify competition for land, but the impact on the mitigation potential (1000 GtCO2) is partially alleviated by productivity increases in the agricultural sector. Moreover, our results indicate that early-century afforestation presumably will not negatively impact carbon removal due to bioenergy CCS in the second half of the 21st century. A sensitivity analysis shows that land-based mitigation is very sensitive to different levels of GHG taxes. Besides that, the mitigation potential of bioenergy CCS highly depends on the development of future bioenergy yields and the availability of geological carbon storage, while for afforestation projects the length of the crediting period is crucial.Peer Reviewe

The impact of high-end climate change on agricultural welfare

Climate change threatens agricultural productivity worldwide, resulting in higher food prices. Associated economic gains and losses differ not only by region but also between producers and consumers and are affected by market dynamics. On the basis of an impact modeling chain, starting with 19 different climate projections that drive plant biophysical process simulations and ending with agro-economic decisions, this analysis focuses on distributional effects of high-end climate change impacts across geographic regions and across economic agents. By estimating the changes in surpluses of consumers and producers, we find that climate change can have detrimental impacts on global agricultural welfare, especially after 2050, because losses in consumer surplus generally outweigh gains in producer surplus. Damage in agriculture may reach the annual loss of 0.3% of future total gross domestic product at the end of the century globally, assuming further opening of trade in agricultural products, which typically leads to interregional production shifts to higher latitudes. Those estimated global losses could increase substantially if international trade is more restricted. If beneficial effects of atmospheric carbon dioxide fertilization can be realized in agricultural production, much of the damage could be avoided. Although trade policy reforms toward further liberalization help alleviate climate change impacts, additional compensation mechanisms for associated environmental and development concerns have to be considered

Investigating afforestation and bioenergy CCS as climate change mitigation strategies

The land-use sector can contribute to climate change mitigation not only by reducing greenhouse gas (GHG) emissions, but also by increasing carbon uptake from the atmosphere and thereby creating negative CO2 emissions. In this paper, we investigate two land-based climate change mitigation strategies for carbon removal: (1) afforestation and (2) bioenergy in combination with carbon capture and storage technology (bioenergy CCS). In our approach, a global tax on GHG emissions aimed at ambitious climate change mitigation incentivizes land-based mitigation by penalizing positive and rewarding negative CO2 emissions from the land-use system. We analyze afforestation and bioenergy CCS as standalone and combined mitigation strategies. We find that afforestation is a cost-efficient strategy for carbon removal at relatively low carbon prices, while bioenergy CCS becomes competitive only at higher prices. According to our results, cumulative carbon removal due to afforestation and bioenergy CCS is similar at the end of 21st century (600–700 GtCO2), while land-demand for afforestation is much higher compared to bioenergy CCS. In the combined setting, we identify competition for land, but the impact on the mitigation potential (1000 GtCO2) is partially alleviated by productivity increases in the agricultural sector. Moreover, our results indicate that early-century afforestation presumably will not negatively impact carbon removal due to bioenergy CCS in the second half of the 21st century. A sensitivity analysis shows that land-based mitigation is very sensitive to different levels of GHG taxes. Besides that, the mitigation potential of bioenergy CCS highly depends on the development of future bioenergy yields and the availability of geological carbon storage, while for afforestation projects the length of the crediting period is crucial.EC/FP7/282846/EU/Low climate IMpact scenarios and the Implications of required Tight emission control Strategies/LIMITSEC/FP7/603542/EU/Land use change: assessing the net climate forcing, and options for climate change mitigation and adaptation/LUC4

Land und Wasser für die Landwirtschaft : Zukunftsaussichten und Zielkonflikte

Land und Wasser gehören zu den wichtigsten Voraussetzungen für menschliches Wohlergehen und landbasiertes Leben. Daher braucht es nachhaltige Strategien zur Land- und Wassernutzung, um eine wachsende Weltbevölkerung zu versorgen und wichtige natürliche Ökosysteme zu erhalten. Landwirtschaftliche Nahrungsmittel-, Material- und Energieproduktion stellt den tiefgreifendsten menschlichen Einfluss auf globale Land- und Wasserressourcen dar. Landwirtschaftliche Land- und Wassernutzung ist daher ein essentieller Faktor für die Nachhaltigkeit von Ressourcenmanagementstrategien. Das hauptsächliche Ziel dieser Dissertation ist es zu untersuchen, wie Landwirtschaft in Zukunft globale Land- und Wasserressourcen beeinflussen könnte. In einzelnen Studien werden Projektionen von landwirtschaftlicher Land- und Wassernutzung entworfen, wobei wichtige Einflussfaktoren wie Bevölkerungswachstum, ökonomische Entwicklung, Bioenergienachfrage, landbasierte Strategien zur Klimawandelvermeidung und nachhaltige Wassernutzungsstrategien berücksichtigt werden. In einer Synthese werden die Resultate der einzelnen Studien kombiniert um folgende Forschungsfragen zu beantworten: (1) Wie verhalten sich verschiedene landwirtschaftliche Strategien in Bezug auf ökologische Folgen für Land- und Wasserressourcen und benötigte Veränderungen des Systems? (2) Wie groß ist der Spielraum für Strategien zur landwirtschaftlichen Land- und Wassernutzung? Zur Untersuchung dieser Forschungsaufgaben wird das „Modell für Landwirtschaft und ihre Auswirkungen auf die Umwelt“ (MAgPIE) angewendet. Mit MAgPIE werden Szenarien zukünftiger landwirtschaftlicher Aktivität entworfen. Dabei werden sozioökonomische Treiber und biophysikalische Randbedingungen in einem Kostenoptimierungsverfahren berücksichtigt. Für diese Dissertation wurde das Modell um einen detaillierten Wassersektor erweitert, der die Implementierung von Wasserverfügbarkeit, Bewässerungsinfrastruktur, nicht-landwirtschaftlichem Wasserbedarf und ökologischem Wasserbedarf verbessert. Die Ergebnisse legen nahe, dass der Schutz von Frischwasserökosystemen vor Degradation durch landwirtschaftliche Aktivitäten ohne fundamentale Auswirkungen auf Ackerlandausdehnung in landbasierte Ökosysteme erreicht werden kann. Landbasierte Strategien zur Klimawandelvermeidung werden wahrscheinlich eine fundamentale Transformation der Landwirtschaft erfordern. Dabei unterscheiden sich die ökologischen Folgen verschiedener Vermeidungsstrategien. Aufforstung und Strategien zur Vermeidung von Emissionen durch Landnutzungsänderungen können helfen, wichtige landbasierte Ökosysteme zu erhalten oder sogar zu erschaffen. Großskaliger Anbau von Bioenergiepflanzen dagegen kann Land- und Frischwasserökosysteme ernstzunehmenden Gefahren aussetzen. Die ausgeprägte Austauschbeziehung zwischen Land und Wasser für die Bioenergieproduktion legt nahe, dass es für nachhaltige Bioenergieproduktion entscheidend ist, sowohl die Land-, als auch die Wassernutzung zu berücksichtigen. Basierend auf den hier vorgestellten Ergebnissen gibt es Hoffnung, dass der Spielraum für die Landwirtschaft groß genug ist um die Anwendung verschiedenster Strategien zu erlauben. Einerseits lassen Ressourcenbeschränkungen reichlich Spielraum für erhöhte Land- und Wassernutzung in der Landwirtschaft. Andererseits scheint das System flexibel genug zu sein, um eine Erhöhung der Nahrungsmittelproduktion bei gleichzeitiger Verringerung des ökologischen Fußabdrucks in Bezug auf Land- und Wassernutzung zu erreichen.Land and water are among the most vital resources for human wellbeing and terrestrial life in general. Therefore, sustainable management strategies for land and water need to be developed in order to sustain a growing world population and important natural ecosystems. Agricultural activity for food, material, and energy production constitutes the most profound anthropogenic influence on global land and water resources. Thus, agricultural land and water-use is a key determinant of the sustainability of resource management strategies. The main research objective of this thesis is to explore, how agriculture might affect global land and water resources in the future. In individual studies, projections of agricultural land and water-use are developed, considering important drivers such as population growth, economic development, bioenergy demand, terrestrial climate change mitigation strategies, and sustainable water-use strategies. In a synthesis, the results of the individual studies are combined in order to answer the following research questions: (1) How do different agricultural strategies compare in terms of environmental implications for land and water resources and required transformation of the system? (2) How large is the operating space for land and water management strategies in agriculture? Methodologically, this thesis relies on the Model of Agricultural Production and its Impacts on the Environment (MAgPIE). MAgPIE can be used to derive scenarios of future agricultural activity by considering socioeconomic drivers and biophysical constraints in a cost optimization framework. For this thesis, the model was extended by a detailed water sector that features an improved representation of water availability, irrigation infrastructure, non-agricultural water demand, and environmental water requirements. Results indicate that protecting freshwater ecosystems from degradation due to agricultural activity can be achieved without fundamental trade-offs in terms of cropland expansion into terrestrial ecosystems. Terrestrial climate change mitigation strategies will likely require a fundamental transformation of the agricultural system. Environmental consequences differ between mitigation strategies. While afforestation and strategies to avoid land-use change emissions can help to protect or even create important terrestrial ecosystems, large-scale bioenergy production can put a severe threat to terrestrial and freshwater ecosystems. Pronounced trade-offs between land and water for bioenergy production suggest that it is crucial to consider both, land and water-use, when aiming at sustainable bioenergy production. Based on the here presented results, there is hope that the operating space for agriculture is large enough to support a variety of management strategies. On the one hand, resource constraints still leave ample space for increasing land and water inputs for agriculture. On the other hand, the system seems flexible enough to allow for increasing food production with a reduced environmental footprint in terms of land and water appropriation

Land and Water for Agriculture: Future Prospects and Trade-Offs

Land und Wasser gehören zu den wichtigsten Voraussetzungen für menschliches Wohlergehen und landbasiertes Leben. Daher braucht es nachhaltige Strategien zur Land- und Wassernutzung, um eine wachsende Weltbevölkerung zu versorgen und wichtige natürliche Ökosysteme zu erhalten. Landwirtschaftliche Nahrungsmittel-, Material- und Energieproduktion stellt den tiefgreifendsten menschlichen Einfluss auf globale Land- und Wasserressourcen dar. Landwirtschaftliche Land- und Wassernutzung ist daher ein essentieller Faktor für die Nachhaltigkeit von Ressourcenmanagementstrategien. Das hauptsächliche Ziel dieser Dissertation ist es zu untersuchen, wie Landwirtschaft in Zukunft globale Land- und Wasserressourcen beeinflussen könnte. In einzelnen Studien werden Projektionen von landwirtschaftlicher Land- und Wassernutzung entworfen, wobei wichtige Einflussfaktoren wie Bevölkerungswachstum, ökonomische Entwicklung, Bioenergienachfrage, landbasierte Strategien zur Klimawandelvermeidung und nachhaltige Wassernutzungsstrategien berücksichtigt werden. In einer Synthese werden die Resultate der einzelnen Studien kombiniert um folgende Forschungsfragen zu beantworten: (1) Wie verhalten sich verschiedene landwirtschaftliche Strategien in Bezug auf ökologische Folgen für Land- und Wasserressourcen und benötigte Veränderungen des Systems? (2) Wie groß ist der Spielraum für Strategien zur landwirtschaftlichen Land- und Wassernutzung? Zur Untersuchung dieser Forschungsaufgaben wird das „Modell für Landwirtschaft und ihre Auswirkungen auf die Umwelt“ (MAgPIE) angewendet. Mit MAgPIE werden Szenarien zukünftiger landwirtschaftlicher Aktivität entworfen. Dabei werden sozioökonomische Treiber und biophysikalische Randbedingungen in einem Kostenoptimierungsverfahren berücksichtigt. Für diese Dissertation wurde das Modell um einen detaillierten Wassersektor erweitert, der die Implementierung von Wasserverfügbarkeit, Bewässerungsinfrastruktur, nicht-landwirtschaftlichem Wasserbedarf und ökologischem Wasserbedarf verbessert. Die Ergebnisse legen nahe, dass der Schutz von Frischwasserökosystemen vor Degradation durch landwirtschaftliche Aktivitäten ohne fundamentale Auswirkungen auf Ackerlandausdehnung in landbasierte Ökosysteme erreicht werden kann. Landbasierte Strategien zur Klimawandelvermeidung werden wahrscheinlich eine fundamentale Transformation der Landwirtschaft erfordern. Dabei unterscheiden sich die ökologischen Folgen verschiedener Vermeidungsstrategien. Aufforstung und Strategien zur Vermeidung von Emissionen durch Landnutzungsänderungen können helfen, wichtige landbasierte Ökosysteme zu erhalten oder sogar zu erschaffen. Großskaliger Anbau von Bioenergiepflanzen dagegen kann Land- und Frischwasserökosysteme ernstzunehmenden Gefahren aussetzen. Die ausgeprägte Austauschbeziehung zwischen Land und Wasser für die Bioenergieproduktion legt nahe, dass es für nachhaltige Bioenergieproduktion entscheidend ist, sowohl die Land-, als auch die Wassernutzung zu berücksichtigen. Basierend auf den hier vorgestellten Ergebnissen gibt es Hoffnung, dass der Spielraum für die Landwirtschaft groß genug ist um die Anwendung verschiedenster Strategien zu erlauben. Einerseits lassen Ressourcenbeschränkungen reichlich Spielraum für erhöhte Land- und Wassernutzung in der Landwirtschaft. Andererseits scheint das System flexibel genug zu sein, um eine Erhöhung der Nahrungsmittelproduktion bei gleichzeitiger Verringerung des ökologischen Fußabdrucks in Bezug auf Land- und Wassernutzung zu erreichen

Validation of land use models

Landuse dynamics in the real world are connected to the ecosystem as well as the economic system, both of which are very complex in nature. Constructing models that produce reliable quantitative results about these dynamics is therefore a very ambitious task. One aim of this article is to make a first proposal for set of validation guidelines for the land use modeling community. While agreeing about standards for land use model validation may in itself be a major step forward, the even bigger challenge is to put this theoretical agreement into effect, i.e. not only to talk about good scientific practice but to change the real processes of model evaluation and development according to those guidelines. Therefore we present a set of tools that we have developed for validating the economic landuse optimization model MAgPIE. It is designed in a way that it can also be used by other land use modeling groups

The impact of climate change mitigation on water demand for energy and food: An integrated analysis based on the Shared Socioeconomic Pathways

Abstract Climate change mitigation, in the context of growing population and ever increasing economic activity, will require a transformation of energy and agricultural systems, posing significant challenges to global water resources. We use an integrated modelling framework of the water-energy-land-climate systems to assess how changes in electricity and land use, induced by climate change mitigation, impact on water demand under alternative socioeconomic (Shared Socioeconomic Pathways) and water policy assumptions (irrigation of bioenergy crops, cooling technologies for electricity generation). The impacts of climate change mitigation on cumulated global water demand across the century are highly uncertain, and depending on socioeconomic and water policy conditions, they range from a reduction of 15,000 km3 to an increase of more than 160,000 km3. The impact of irrigation of bioenergy crops is the most prominent factor, leading to significantly higher water requirements under climate change mitigation if bioenergy crops are irrigated. Differences in socioeconomic drivers and fossil fuel availability result in significant differences in electricity and bioenergy demands, in the associated electricity and primary energy mixes, and consequently in water demand. Economic affluence and abundance of fossil fuels aggravate pressures on water resources due to higher energy demand and greater deployment of water intensive technologies such as bioenergy and nuclear power. The evolution of future cooling systems is also identified as an important determinant of electricity water demand. Climate policy can result in a reduction of water demand if combined with policies on irrigation of bioenergy, and the deployment of non-water-intensive electricity sources and cooling types

The global economic long-term potential of modern biomass in a climate-constrained world

Low-stabilization scenarios consistent with the 2 °C target project large-scale deployment of purpose-grown lignocellulosic biomass. In case a GHG price regime integrates emissions from energy conversion and from land-use/land-use change, the strong demand for bioenergy and the pricing of terrestrial emissions are likely to coincide. We explore the global potential of purpose-grown lignocellulosic biomass and ask the question how the supply prices of biomass depend on prices for greenhouse gas (GHG) emissions from the land-use sector. Using the spatially explicit global land-use optimization model MAgPIE, we construct bioenergy supply curves for ten world regions and a global aggregate in two scenarios, with and without a GHG tax. We find that the implementation of GHG taxes is crucial for the slope of the supply function and the GHG emissions from the land-use sector. Global supply prices start at $5 GJ−1 and increase almost linearly, doubling at 150 EJ (in 2055 and 2095). The GHG tax increases bioenergy prices by$5 GJ−1 in 2055 and by $10 GJ−1 in 2095, since it effectively stops deforestation and thus excludes large amounts of high-productivity land. Prices additionally increase due to costs for N2O emissions from fertilizer use. The GHG tax decreases global land-use change emissions by one-third. However, the carbon emissions due to bioenergy production increase by more than 50% from conversion of land that is not under emission control. Average yields required to produce 240 EJ in 2095 are roughly 600 GJ ha−1 yr−1 with and without tax