Climate Impact Mitigation Research Articles

Nordic biogas model in international contexts: Early-stage decision support for adaptation.

Global waste management challenges demand innovative and multi-functional solutions. The Nordic Biogas Model (NBM) based on anaerobic digestion of organic waste and valorization of its outputs provides several benefits beyond waste treatment such as energy recovery, nutrient recycling and climate impact mitigation. Despite these benefits, its international adoption remains limited, revealing an implementation gap. One way to address this gap is to adapt technology and knowledge from the provider to each specific context. This involves the embedding of the technology into the local context and the development of conditions such as formal and informal institutions over time. Based on decade-long interactions with Nordic companies and municipal decision-makers, we highlight the importance of communication between the technology provider and potential adopter, to ensure that the diverse sustainability benefits of NBM are acknowledged. Furthermore, most provider companies can benefit from a systematic guideline that supports early-stage decision-making as an essential component of the adaptation and implementation of the NBM in diverse international contexts. In this article, we offer suggestions for both: (1) how to better communicate the sustainability benefits of the NBM, and (2) how to assess the risk and opportunities of entering new markets at the early stages of decision-making.

Development of a generalized pseudo-probabilistic approach for characterizing ecological conditions in estuaries using secondary data

Under the best circumstances, achieving or sustaining optimum ecological conditions in estuaries is challenging. Persistent information gaps in estuarine data make it difficult to differentiate natural variability from potential regime shifts. Long-term monitoring is critical for tracking ecological change over time. In the United States (US), many resource management programs are working at maximum capacity to address existing state and federal water quality mandates (e.g., pollutant load limits, climate impact mitigation, and fisheries management) and have little room to expand routine sampling efforts to conduct periodic ecological baseline assessments, especially at state and local scales. Alternative design, monitoring, and assessment approaches are needed to help offset the burden of addressing additional data needs to increase understanding about estuarine system resilience when existing monitoring data are sparse or spatially limited. Research presented here offers a pseudo-probabilistic approach that allows for the use of found or secondary data, such as data on hand and other acquired data, to generate statistically robust characterizations of ecological conditions in estuaries. Our approach uses a generalized pseudo-probabilistic framework to synthesize data from different contributors to inform probabilistic-like baseline assessments. The methodology relies on simple geospatial techniques and existing tools (R package functions) developed for the US Environmental Protection Agency to support ecological monitoring and assessment programs like the National Coastal Condition Assessment. Using secondary estuarine water quality data collected in the Northwest Florida (US) estuaries, demonstrations suggest that the pseudo-probabilistic approach produces estuarine condition assessment results with reasonable statistical confidence, improved spatial representativeness, and value-added information. While the pseudo-probabilistic framework is not a substitute for fully evolved monitoring, it offers a scalable alternative to bridge the gap between limitations in resource management capability and optimal monitoring strategies to track ecological baselines in estuaries over time.

Hydroprocessing of fossil fuel-based aviation kerosene – Technology options and climate impact mitigation potentials

Aviation contributes about 4 % of global anthropogenic climate forcing primarily by contrails, CO2 and NOx emissions. Renewably sourced aviation kerosene can help to reduce the climate impact from CO2 and from contrails, but so far, its production capacities are very small. Hence, the climate impact of using fossil fuel-based kerosene with a hydrogen content increased by hydroprocessing as short term mitigation measure is studied here. Therefore, the change in net energy forcing (ΔEFnet) in 2019 is calculated as the sum of the change in contrail energy forcing (ΔEFcontrail) and additional CO2 emissions (ΔEFhydroprocessing) from aviation kerosene hydroprocessing (ΔEFnet = ΔEFcontrail + ΔEFhydroprocessing). The results show that hydroprocessed aviation kerosene can reduce the net energy forcing EFnet by about 33 % with ΔEFhydroprocessing penalty of 5 %-points. Increasing the hydroprocessing severity increases the relative climate benefit, which is only slightly affected by the emissions factor for hydroprocessing or the choice of the time horizon. Data limitations about fuel composition and its effect on contrails and climate cause considerable uncertainties and the fuel's compliance with specification standards needs consideration. This study on the climate effect of hydroprocessed fossil kerosene can help to assess near-term measures to reduce the climate impact from aviation.

ARMOSA Model Parametrization for Winter Durum Wheat Cultivation under Diverse Cropping Management Practices in a Mediterranean Environment

In anticipation of climate changes, strategic soil management, encompassing reduced tillage and optimized crop residue utilization, emerges as a pivotal strategy for climate impact mitigation. Evaluating the transition from conventional to conservative cropping systems, especially the equilibrium shift in the medium to long term, is essential. ARMOSA, a robust crop simulation model, adeptly responds to varied soil management practices such as no tillage, minimum tillage, and specific straw management options such as chopping and incorporating crop residue into the soil (with or without prior nitrogen and water addition before ploughing). It effectively captures dynamic fluctuations in total organic carbon over an extended period. While challenges persist in precisely predicting grain yield due to climatic intricacies, ARMOSA stands out as a valuable and versatile tool. The model excels in comprehending and simulating wheat cultivar responses in dynamic agricultural ecosystems, shedding light on phenological patterns, biomass accumulation, and soil organic carbon dynamics. This research significantly advances our understanding of the intricate complexities associated with past wheat cultivation in diverse environmental conditions. ARMOSA’s ability to inform decisions on conservation practices positions it as a valuable asset for researchers, agronomists, and policymakers navigating the challenges of sustainable agriculture amidst climate change. Its real-world significance lies in its potential to guide informed decisions, contributing to global efforts in sustainable agriculture and climate resilience.

How Do Carbon Credits Influence Corporate Sustainability Practices?

Climate change is the pivotal challenge of this modern era, which needs broad sustainability practices in different sectors. Industrial sectors are at the core of climate impact mitigation, considering that these industries belong to the most significant GHG emitters, and one of the critical tools in this fight is carbon credits. Carbon credits allow an organization to offset its GHG emissions through purchase; the latter is generated through specific projects that reduce or avoid GHG emissions. In this paper, the carbon credit issue has become part of corporate sustainability strategies, given their implications for how business is done, incentives, and the challenges inherent in this approach. Given the rise in sustainability goals and regulations, carbon credits foster a better financial foundation and corporate reputation. However, fraud, lack of transparency, and price volatility remain challenging. Critics claim that reliance on carbon credits undermines genuine emission reductions and extends environmental injustices. Case studies on carbon credit use vary from large corporations like Microsoft and Shell to SMEs like Illy. The effective use of carbon credits calls for a balanced mix of direct emission reductions and carbon offsetting that will create significant sustainability impacts. This paper underlines that the full integration of carbon credits within a company-wide corporate sustainability strategy allows the challenges linked to climate change to be comprehensively met.

An Evaluation of Nutritional Security Impacts of Climate-Smart Adaptation Practices among Smallholder Farmers of Eastern Oromia, Ethiopia

Climate impact mitigation through improved agricultural practices is one means by which agricultural productivity increases to meet the growing food demands in the world. This study evaluated the impacts of climate-smart Practices on rural households’ nutrition security. The study used both primary and secondary data sources. Primary data was collected from sample respondents in the 2020/21 production year. Descriptive statistics and econometric models were employed for data analysis. Multinomial logit result indicated that the probability of adopting climate-smart agricultural practices is influenced by the education level of the head, extension contact, livestock holding, membership coop, market information, advice on land management, climate change information, farmers training, climate change perception, and weather road distance. The result from GPS estimation indicated that treatment level two the number of climate-smart practices increases household nutritional status by16%. Likewise, treatment level three and four of the number of climate-smart practices increases the household level nutritional status by 37% and 76% respectively over that of treatment level one of the climate-smart practices and is significant at a 1% statistical probability level. This study has found evidence that the adoption of climate-smart on the households’ nutrition security status. Therefore, the result of this study would be expected to significantly contribute as policy and strategic inputs for policymakers in designing rural livelihood improvement policies and to the beneficiary in enhancing their welfare and living standard.

Climate Impact Mitigation Potential of Novel Aircraft Features

This work presents a transpacific airliner designed for minimal climate impact, incorporating several novel design features. These include open rotor engines, sustainable aviation fuels, natural laminar flow airfoils, and riblets. The design’s configuration and mission have been optimised simultaneously using a combination of standard preliminary techniques, experimental data, a multi-point mission analysis, and a model of average temperature response. It is demonstrated that, on an 8000 km mission, the design offers an 89.8% reduction in average temperature response relative to an Airbus A330-200, at the expense of a 7.3% increase in direct operating cost. The sensitivity of these results is investigated by comparing the performance over a range of operating conditions. In addition, several alternative designs incorporating only some of the above-mentioned features are analysed, allowing for an assessment of their individual contribution. Finally, a life-cycle average temperature response analysis is presented to place the climate impact of operation, manufacturing and end-of-life procedures in context.

An In-Depth Life Cycle Assessment (LCA) of Lithium-Ion Battery for Climate Impact Mitigation Strategies

Battery energy storage systems (BESS) are an essential component of renewable electricity infrastructure to resolve the intermittency in the availability of renewable resources. To keep the global temperature rise below 1.5 °C, renewable electricity and electrification of the majority of the sectors are a key proposition of the national and international policies and strategies. Thus, the role of BESS in achieving the climate impact mitigation target is significant. There is an unmet need for a detailed life cycle assessment (LCA) of BESS with lithium-ion batteries being the most promising one. This study conducts a rigorous and comprehensive LCA of lithium-ion batteries to demonstrate the life cycle environmental impact hotspots and ways to improve the hotspots for the sustainable development of BESS and thus, renewable electricity infrastructure. The whole system LCA of lithium-ion batteries shows a global warming potential (GWP) of 1.7, 6.7 and 8.1 kg CO2 eq kg−1 in change-oriented (consequential) and present with and without recycling credit consideration, scenarios. The GWP hotspot is the lithium-ion cathode, which is due to lithium hexafluorophosphate that is ultimately due to the resource-intensive production system of phosphorous, white, liquid. To compete against the fossil economy, the GWP of BESS must be curbed by 13 folds. To be comparable with renewable energy systems, hydroelectric, wind, biomass, geothermal and solar (4–76 g CO2 eq kWh−1), 300 folds reduction in the GWP of BESS will be necessary. The areas of improvement to lower the GWP of BESS are as follows: reducing scopes 2–3 emissions from fossil resource use in the material production processes by phosphorous recycling, increasing energy density, increasing lifespan by effective services, increasing recyclability and number of lives, waste resource acquisition for the battery components and deploying multi-faceted integrated roles of BESS. Achieving the above can be translated into an overall avoided GWP of up to 82% by 2040.

Marine biomass for a circular blue‐green bioeconomy? A life cycle perspective on closing nitrogen and phosphorus land‐marine loops

AbstractA blue‐green bioeconomy revolution is underway in Europe, with particular attention being paid to the development of new or underutilized marine biomass resources. The wild harvest and mariculture of low‐trophic non‐fed species of marine biomass may be contributing to circular economies, the mitigation of environmental problems such as eutrophication and climate change through the uptake of nutrients and carbon, while also recovering finite phosphorus from marine coastal environments, thus contributing to food security. The present study provides a cradle‐to‐gate life cycle perspective on seven established or innovative/emerging marine biomass utilization cases in Sweden: mariculture of sugar kelp, blue mussels, and ascidians and the harvest of invasive Pacific oysters along the Skagerrak coast, the mariculture of blue mussels in the Baltic sea, the harvest of common reed in the Stockholm archipelago, and the harvest of beach‐cast seaweed in Gotland. Results showed that the mariculture cases were found to contribute to eutrophication and climate impact mitigation (at gate). All cases were found to contribute to closing the loop on phosphorus by enabling recovery from marine or coastal environments, bridging marine–land flows, all while performing well from an environmental perspective with a relatively low cumulative energy demand and low carbon and nutrient footprints. This highlights the potential of low‐trophic biomass to contribute to phosphorus security in the future, and demonstrates the value of industrial ecology tools such as LCA in support of this imminent Decade of Ocean Science for Sustainable Development.

Concept of climate-charged airspaces: a potential policy instrument for internalizing aviation's climate impact of non-CO2 effects

ABSTRACT Approximately 50–75% of aviation's climate impact is caused by non-CO2 effects, like the production of ozone and the formation of contrail cirrus clouds, which can be effectively prevented by re-routing flights around highly climate-sensitive areas. Here, we discuss options how to incentivize re-routing approaches and apply multicriteria trajectory optimizations to demonstrate the feasibility of the concept of climate-charged airspaces (CCAs). We show that although climate-optimized re-routing results in slightly longer flight times, increased fuel consumption and higher operating costs, it is more climate-friendly compared to a cost-optimized routing. In accordance to other studies, we find that the averaged temperature response over 100 years (ATR) of a single flight can be reduced by up to 40%. However, if mitigation efforts are associated with a direct increase in costs, there is a need for climate policies. To address the lack of incentivizing airlines to internalize their climate costs, this study focuses on the CCA concept, which imposes a climate charge on airlines when operating in highly climate-sensitive areas. If CCAs are (partly) bypassed, both climate impact and operating costs of a flight can be reduced: a more climate-friendly routing becomes economically attractive. For an exemplary North-Atlantic network, CCAs create a financial incentive for climate mitigation, achieving on average more than 90% of the climate impact reduction potential of climate-optimized trajectories (theoretical maximum, benchmark). Key policy insights Existing climate policies for aviation do not address non- effects, which are very sensitive to the location and the timing of the emission. By imposing a temporary climate charge for airlines that operate in highly climate-sensitive regions, the trade-off between economic viability and environmental compatibility could be resolved: Climate impact mitigation of non- effects coincides with cutting costs. To ensure easy planning and verification, climate charges are calculated analogously to en-route and terminal charges. For climate mitigation it is therefore neither necessary to monitor emissions ( , etc.) nor to integrate complex non- effects into flight planning procedures of airlines. Its implementation is feasible and effective.

Fuel Planning Strategies Considering Operational Uncertainties of Aerodynamic Formation Flight

The operational concept of aerodynamic formation flight, also referred to as aircraft wake-surfing for efficiency (AWSE), has high potential in terms of fuel savings and climate impact mitigation. In order to implement this concept, many technological and operational challenges have to be coped with. As the fuel consumption during a mission strongly depends on a successful execution of AWSE, the existing uncertainties regarding flight planning increase. While a conservative fuel planning ensures a follower to complete the mission even in the case of a formation failure, it might result in high amounts of excess fuel and, therefore, additional fuel consumption. In this study, this issue is addressed by the adaptation of flight planning procedures to the requirements of AWSE focusing on fuel planning in particular, considered from the perspective of a designated follower aircraft of a two-aircraft formation. This trade-off is modeled as an n-action two-event decision-making problem. Each of the possible actions is represented by a combination of mission routing and a corresponding diversion airport, taking atmospheric effects (e.g., wind) into account in order to determine the resulting amount of trip fuel. The two events under consideration are a total formation failure in contrast to a complete success. Based on a scenario with a set of double origin destination pairs characterizing the formations and representative weather patterns for the North Atlantic region, each action is analyzed with regard to the expected fuel consumption and expense. Based on a set of assumed formation success probabilities, we find that the proposed method holds a savings potential to reduce the follower’s fuel consumption by 4.8% and its monetary expenses by 1.2% compared with a conventional flight planning. In order to gain a monetary profit margin applying this method, the required formation success probability is shown to vary between 92% and 96%, depending on the assumed fuel price.

Climate Impact Mitigation Potential of European Air Traffic in a Weather Situation with Strong Contrail Formation

Air traffic contributes to anthropogenic global warming by about 5% due to CO2 emissions and non-CO2 effects, which are primarily caused by the emission of NOx and water vapor as well as the formation of contrails. Since—in the long term—the aviation industry is expected to maintain its trend to grow, mitigation measures are required to counteract its negative effects upon the environment. One of the promising operational mitigation measures that has been a subject of the EU project ATM4E is climate-optimized flight planning by considering algorithmic climate change functions that allow for the quantification of aviation-induced climate impact based on the emission’s location and time. Here, we describe the methodology developed for the use of algorithmic climate change functions in trajectory optimization and present the results of its application to the planning of about 13,000 intra-European flights on one specific day with strong contrail formation over Europe. The optimization problem is formulated as bi-objective continuous optimal control problem with climate impact and fuel burn being the two objectives. Results on an individual flight basis indicate that there are three major classes of different routes that are characterized by different shapes of the corresponding Pareto fronts representing the relationship between climate impact reduction and fuel burn increase. On average, for the investigated weather situation and traffic scenario, a climate impact reduction in the order of 50% can be achieved by accepting 0.75% of additional fuel burn. Higher mitigation gains would only be available at much higher fuel penalties, e.g., a climate impact reduction of 76% associated with a fuel penalty of 12.8%. However, these solutions represent much less efficient climate impact mitigation options.

Climate Impact Mitigation Potential of Formation Flight

The aerodynamic formation flight, which is also known as aircraft wake-surfing for efficiency (AWSE), enables aircraft to harvest the energy inherent in another aircraft’s wake vortex. As the thrust of the trailing aircraft can be reduced during cruise flight, the resulting benefit can be traded for longer flight time, larger range, less fuel consumption, or cost savings accordingly. Furthermore, as the amount and location of the emissions caused by the formation are subject to change and saturation effects in the cumulated wake of the formation can occur, AWSE can favorably affect the climate impact of the corresponding flights. In order to quantify these effects, we present an interdisciplinary approach combining the fields of aerodynamics, aircraft operations and atmospheric physics. The approach comprises an integrated model chain to assess the climate impact for a given air traffic scenario based on flight plan data, aerodynamic interactions between the formation members, detailed trajectory calculations as well as on an adapted climate model accounting for the saturation effects resulting from the proximity of the emissions of the formation members. Based on this approach, we derived representative AWSE scenarios for the world’s major airports by analyzing and assessing flight plans. The resulting formations were recalculated by a trajectory calculation tool and emission inventories for the scenarios were created. Based on these inventories, we quantitatively estimated the climate impact using the average temperature response (ATR) as climate metric, calculated as an average global near surface temperature change over a time horizon of 50 years. It is shown, that AWSE as a new operational procedure has a significant mitigation potential on climate impact. For a global formation flight scenario, we estimated the average relative change of climate response to range between 22% and 24% while the relative fuel saving effects sum up to 5–6%.

Remote sensing of methane leakage from natural gas and petroleum systems revisited

Abstract. The switch from the use of coal to natural gas or oil for energy generation potentially reduces greenhouse gas emissions and thus the impact on global warming and climate change because of the higher energy creation per CO2 molecule emitted. However, the climate benefit over coal is offset by methane (CH4) leakage from natural gas and petroleum systems, which reverses the climate impact mitigation if the rate of fugitive emissions exceeds the compensation point at which the global warming resulting from the leakage and the benefit from the reduction of coal combustion coincide. Consequently, an accurate quantification of CH4 emissions from the oil and gas industry is essential to evaluate the suitability of natural gas and petroleum as bridging fuels on the way to a carbon-neutral future. We show that regional CH4 release from large oil and gas fields can be monitored from space by using dense daily recurrent measurements of the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor satellite to quantify emissions and leakage rates. The average emissions for the time period 2018/2019 from the five most productive basins in the United States, the Permian, Appalachian, Eagle Ford, Bakken, and Anadarko, are estimated to be 3.18±1.13, 2.36±0.88, 1.37±0.63, 0.89±0.56, and 2.74±0.74 Mt yr−1, respectively. This corresponds to CH4 leakage rates relative to the associated production between 1.2 % and 1.4 % for the first four production regions, which are consistent with bottom-up estimates and likely fall below the break-even leakage rate for immediate climate benefit. For the Anadarko Basin, the fugitive emission rate is larger and amounts to 3.9±1.1 %, which likely exceeds the break-even rate for immediate benefit and roughly corresponds to the break-even rate for a 20-year time horizon. The determined values are smaller than previously derived satellite-based leakage rates for the time period 2009–2011, which was an early phase of hydraulic fracturing, indicating that it is possible to improve the climate footprint of the oil and gas industry by adopting new technologies and that efforts to reduce methane emissions have been successful. For two of the world's largest natural gas fields, Galkynysh and Dauletabad in Turkmenistan, we find collective methane emissions of 3.26±1.17 Mt yr−1, which corresponds to a leakage rate of 4.1±1.5 %, suggesting that the Turkmen energy industry is not employing methane emission avoidance strategies and technologies as successfully as those currently widely used in the United States. The leakage rates in Turkmenistan and in the Anadarko Basin indicate that there is potential to reduce fugitive methane emissions from natural gas and petroleum systems worldwide. In particular, relatively newly developed oil and gas plays appear to have larger leakage rates compared to more mature production areas.

Climate Change Impact on Foreign Direct Investment Inflows: A Dynamic Assessment at the Global, Regional and Economic Level

Climate and environment-related international private finance flows have considerably risen since the early 1990s. The evidence on both sectoral sensitivities and increased climate-relevant investments suggests a potential link between international investment flows and climate variables, which to date remains largely unexplored. This paper examines how climate change, defined by temperature and precipitation changes, influences aggregate Foreign Direct Investment (FDI) inflows across regions and economies. We employ ARDL-based mean-group type estimators on a panel data from 1995 to 2014 covering 80 countries. We find that FDI flows are sensitive to changes in temperature and precipitation. Temperature has a long-run negative impact on world aggregate FDI flows, while precipitation shows a positive impact. Findings suggest mostly long-run and heterogeneous impacts of temperature and precipitation changes across regions. Findings further show that in the long-run temperature changes decrease FDI flows in developing countries, but increase FDI flows in developed economies. This analysis could provide a new perspective to the on-going efforts of financing climate impact mitigation and adaptation. They could also offer information about rethinking global FDI policies in the context of climate change.

Flexibility From Energy Systems Integration: Supporting Synergies Among Sectors

Energy systems integration, or sector coupling, has several drivers that span climate impact mitigation and economics to social and regulatory considerations. A key question is what is sector coupling, and how does it impact the flexibility of the energy system? Here, the energy system includes several sectorsmelectricity, gas, heat, and transportationmthat have been independent for decades in most countries except for their coupling via combined heat and power (CHP) units. In energy systems integration, some sectors may provide flexibility to other sectors, while other sectors will require flexibility when interlinking. To support these synergies among sectors, it is important to explore and quantify mutual interactions as well as seek examples of how these integrations can provide flexibility and other benefits. From the perspective of the electricity sector, it is important to ensure that there is enough flexibility in the interconnected systems to support decarbonization goals, such as those set in the Paris Agreement, while ensuring operational reliability.

Exploring the potential for biomethane production by willow pyrolysis using life cycle assessment methodology

BackgroundBiomethane, as a potential substitute for natural gas, reduces the use of fossil-based sources, promoting bioenergy applications. Biomethane for energy use can be produced using a variety of biomass types and technologies. Biomethane from farmland crops is currently produced by anaerobic digestion (AD) of energy crops, which is a biological treatment of organic material resulting in biomethane and digestate. Recently, thermochemical conversion technologies of biomass to biomethane have gained attention. Pyrolysis is a thermochemical process whereby woody biomass is converted to fuel gas and biochar. This study assessed the land use efficiency of producing biomethane through a maize-based AD system compared with switching to a willow-based biomethane system using pyrolysis as an emerging technology. The energy performance and climate impact of the two pathways were assessed from a land use perspective, using life cycle assessment methodology. The entire technical system, from biomass production to delivery of biomethane as the end product, was included within the analysis. The study also investigated how the climate impact was affected when biochar was applied to soil to act as a soil amendment and carbon sequestration agent or when biochar was used as an energy source.ResultsPyrolysis of willow had a higher external energy ratio and climate mitigation effect than maize-based AD as a result of lower primary energy inputs and lower methane loss in the pyrolysis process and upgrading units. Furthermore, the biochar from willow pyrolysis, when used as a soil amendment or energy source, contributed significantly to the climate impact mitigation potential in both cases. Substituting fossil gas with biomethane gave a considerable reduction in climate impact in all scenarios, especially in the case of willow pyrolysis. The willow pyrolysis system acted as a carbon sink, resulting in a negative climate impact, counteracting global warming.ConclusionFrom a land use perspective, the transition from maize-based AD to a willow-based pyrolysis system for biomethane production could be beneficial regarding the energy performance and climate impact. Application of biochar to the soil in the willow scenario contributed significantly to counteracting emissions of greenhouse gases.

The influence of system boundaries and baseline in climate impact assessment of forest products

This article aims to explore how different assumptions about system boundaries and setting of baselines for forest growth affect the outcome of climate impact assessments of forest products using life cycle assessment (LCA), regarding the potential for climate impact mitigation from replacing non-forest benchmarks. This article attempts to explore how several assumptions interact and influence results for different products with different service life lengths. Four products made from forest biomass were analysed and compared to non-forest benchmarks using dynamic LCA with time horizons between 0 and 300 years. The studied products have different service lives: butanol automotive fuel (0 years), viscose textile fibres (2 years), a cross-laminated timber building structure (50 years) and methanol used to produce short-lived (0 years) and long-lived (20 years) products. Five calculation setups were tested featuring different assumptions about how to account for the carbon uptake during forest growth or regrowth. These assumptions relate to the timing of the uptake (before or after harvest), the spatial system boundaries (national, landscape or single stand) and the land-use baseline (zero baseline or natural regeneration). The implications of using different assumptions depend on the type of product. The choice of time horizon for dynamic LCA and the timing of forest carbon uptake are important for all products, especially long-lived ones where end-of-life biogenic emissions take place in the relatively distant future. The choice of time horizon is less influential when using landscape- or national-level system boundaries than when using stand-level system boundaries and has greater influence on the results for long-lived products. Short-lived products perform worse than their benchmarks with short time horizons whatever spatial system boundaries are chosen, while long-lived products outperform their benchmarks with all methods tested. The approach and data used to model the forest carbon uptake can significantly influence the outcome of the assessment for all products. The choices of spatial system boundaries, temporal system boundaries and land-use baseline have a large influence on the results, and this influence decreases for longer time horizons. Short-lived products are more sensitive to the choice of time horizon than long-lived products. Recommendations are given for LCA practitioners: to be aware of the influence of method choice when carrying out studies, to use case-specific data (for the forest growth) and to communicate clearly how results can be used.

Climate-Compatible Air Transport System—Climate Impact Mitigation Potential for Actual and Future Aircraft

Aviation guarantees mobility, but its emissions also contribute considerably to climate change. Therefore, climate impact mitigation strategies have to be developed based on comprehensive assessments of the different impacting factors. We quantify the climate impact mitigation potential and related costs resulting from changes in aircraft operations and design using a multi-disciplinary model workflow. We first analyze the climate impact mitigation potential and cash operating cost changes of altered cruise altitudes and speeds for all flights globally operated by the Airbus A330-200 fleet in the year 2006. We find that this globally can lead to a 42% reduction in temperature response at a 10% cash operating cost increase. Based on this analysis, new design criteria are derived for future aircraft that are optimized for cruise conditions with reduced climate impact. The newly-optimized aircraft is re-assessed with the developed model workflow. We obtain additional climate mitigation potential with small to moderate cash operating cost changes due to the aircraft design changes of, e.g., a 32% and 54% temperature response reduction for a 0% and 10% cash operating cost increase. Hence, replacing the entire A330-200 fleet by this redesigned aircraft ( M a c r = 0.72 and initial cruise altitude (ICA) = 8000 m) could reduce the climate impact by 32% without an increase of cash operating cost.

Vegetation dynamics and plant species distribution under changing climates

Quaternary climate variability strongly affected ecosystems and vegetation. Climatic oscillations became more moderate during the Holocene, and vegetation reorganizations in response to climate eventually shifted from the biome to the community level during the past 11500 years. Superimposed on climate variability, land use significantly altered European vegetation structure and composition during the mid and late Holocene. Anthropogenic alterations of vegetation during the past 8000 years included contractions and extensions of ranges and realized niches of species. Such paleo-ecological information can be used to infer measures to preserve future biodiversity and ecosystem services under global change conditions. The combination of paleoecological evidence with dynamic vegetation modeling allows investigating spatially explicit transient stages of past and future vegetation shifts under global change conditions. Specifically, dynamic modelling projections may be used to investigate open paleoecological questions or to plan paleo-validated climate-impact mitigation strategies at local to regional scales