The European Union is not currently on track to meet its climate mitigation targets, and emissions reductions alone are unlikely to achieve net-zero greenhouse gas emissions. Carbon dioxide removal (CDR) will therefore be required to address residual emissions and potentially compensate for historical emissions. However, both CDR technologies and the policy frameworks governing them remain at an early stage of development, creating uncertainty regarding future deployment pathways.
The diversity of available CDR methods, combined with unresolved questions surrounding permanence, funding mechanisms, and governance, complicates the development of effective policy. While the Netherlands has published a roadmap outlining possible CDR developments to 2050, uncertainties remain regarding which policy interventions will be required and how they should adapt over time.
This thesis examines the research question: What contribution can Dynamic Adaptive Policy Pathways (DAPP) make to the development of carbon dioxide removal in the Netherlands? DAPP was originally developed to deal with adaptation decision-making within water systems and has not previously been used for the CDR sector. Therefore, DAPP was applied to the Dutch CDR sector to assess its usefulness as a policy-support tool. Pathways were developed iteratively using academic literature and policy documents and subsequently evaluated through stakeholder interviews representing a range of perspectives within the Dutch CDR sector. Four pathway maps were constructed based on two scenario dimensions: free market versus mandated CDR and the eligibility of permanent CDR only versus both permanent and temporary removals.
The interviews highlighted significant uncertainty regarding the definition of permanence and the role of temporary removals. Stakeholders suggested that temporary removals may contribute to addressing short-term emissions, although implementation mechanisms remain unclear. Discussions also emphasised the need for additional financial incentives and regulatory space for setting up pilot projects as potential drivers of CDR deployment.
The DAPP approach proved valuable for identifying uncertainties, constraints, trade-offs, and stakeholder perspectives; however, the resulting pathway maps were less effective in supporting detailed policy analysis or the development of concrete policy measures. Policymakers should prioritise defining residual emissions, clarifying the role of temporary removals, and assessing funding or mandate-based mechanisms to support CDR deployment. Future policy should also consider competition for CCS storage capacity and continue supporting emerging technologies. Further research could strengthen the DAPP approach by exploring pathway development at a higher level of aggregation, where CDR is considered alongside mitigation measures, or an approach focusing on specific CDR methods.
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This thesis applies RED III-equivalent non-GHG ecological sustainability criteria to EU crude oil supply chains as a structured thought experiment. The Renewable Energy Directive III (RED III) imposes strict ecological no-go zones and governance requirements on biomass, while crude oil, despite causing comparable or greater ecological harm, faces no equivalent regulation. This research addresses that asymmetry through five sub-questions, moving from criteria mapping through compliance assessment, typological extension, and scenario analysis to policy implications.

Four representative supply chains (Alberta, Canada; Ekofisk, Norway; Niger Delta, Nigeria; and Ghawar, Saudi Arabia) are assessed against fifteen operationalised indicators derived from Articles 29(2)–(7) and 30 of RED III. These results are extended typologically to the fourteen largest EU import source countries using WWF biome classification and the 2017 Natural Resource Governance Index. This extension assigns compliance by biome similarity rather than site-specific assessment, and 22.7% of imports remain unassessed.

Under the strict primary scenario, only 17.6% of current EU crude oil imports qualify as compliant, and the share never exceeds 23.2% under any scenario. Governance failure, not ecological harm, is the primary driver of exclusion, accounting for 25.4% of imports against 8.0% on ecological grounds. Norway and the United Kingdom are the only confirmed compliant sources. Under no IEA demand scenario does compliant supply approach projected demand within the transition period.

The research concludes that the asymmetry between biomass and crude oil lacks an ecological justification: excluding crude oil from an equivalent framework is a political choice rather than an ecological one, and a form of environmental injustice. Because the compliance risk lies in governance rather than spatial overlap, and a hard threshold would exclude most imports at once, any equivalent framework would need to be governance-first, verification-based, and phased. ... Read more

The EU Packaging and Packaging Waste Regulation (PPWR) sets recycled content targets for polyethylene terephthalate (PET) packaging at the product level for 2040 and enables future EU legislation on bio-based targets. However, its effect on the projected environmental impacts of the European PET packaging sector in 2040 remains unclear. This study addresses the research question: “What magnitude and direction of change in projected environmental impacts of the European PET packaging sector is achievable through feedstock substitution in the context of the Packaging and Packaging Waste Regulation in 2040?”

The research approach combines static prospective Material Flow Analysis (pMFA) with prospective Life Cycle Assessment (pLCA). Three foreground scenarios explore the Business-as-usual (BAU), PPWR recycled content targets (Scenario 1), and a potential Joint Target with bio-based-content targets (Scenario 2). The future PET packaging demand is represented by a packaging market mix. The pMFA uses data on projected feedstock shares from the Plastics Integrated Assessment (PLAIA), part of the Integrated Assessment Model (IAM) IMAGE, and is conducted in the subSTance flow ANalysis software. The pLCA adopts the ecoinvent v3.12 database modified using premise, applying the IAM IMAGE under three Shared Socioeconomic Pathway (SSP) scenarios based on SSP2 with medium emissions (SSP2-M), low emissions (SSP2-L), and very low high overshoot (SSP2-VLHO). The pLCA is performed in Activity Browser using the Environmental Footprint v3.1.

Results show that PPWR recycled content targets are highly environmentally beneficial, with Scenarios 1 and 2 reducing environmental impacts across all impact categories compared to BAU and achieving similar climate change impact reductions of -64% and -59%, respectively. Meeting the recycled content targets requires imports of recycled PET, indicating a risk of circularity leakage. A Joint Target, allowing bio-based feedstock to partially replace recycled feedstock, o]ers no additional advantage over recycled content targets, with Scenario 2 showing moderately higher environmental impacts than Scenario 1. The largest di]erences are observed in land use (-17 percentage points (pp)), terrestrial eutrophication, and particulate matter formation (both -10 pp), all relative to BAU. At the process level, energy production and manufacturing are the dominant contributors across most impact categories. At the life cycle stage level, PET polymer production and EoL management emerge as hotspots, with Bio-PET showing disproportionately high land use impacts in Scenario 2. The baseline assumes sugar beet as the biomass source for bioethanol and wood for terephthalic acid production. Sensitivity analysis with wheat for bioethanol production shows similar results.

Policy recommendations include scaling up recycling infrastructure to address the identified risk of circularity leakage and prioritizing demand reduction and reuse quotas. Main limitations include uncertainties resulting from reconciling multiple data sources in the pMFA, and the lack of prospective foreground unit process data for the chemical sector in the pLCA. Future research should develop and integrate such data, develop regional classification in IMAGE aligned with political entities, and evaluate the effects of the PPWR on further packaging materials to allow cross-sector assessment.

Resolver link to Supplementary data: Prospective Life Cycle Assessment of the European PET Packaging Sector: https://doi.org/10.4121/508cfd64-f031-47ff-ae86-58f0b21b7a51 ... Read more

Among the portfolio of emerging carbon dioxide removal (CDR) approaches to mitigate global warming, macroalgae cultivation and sinking (MCS) has recently attracted increasing scientific, commercial, and policy interest, due to its theorised potential to enhance oceanic carbon uptake. Yet, much remains unknown about the environmental implications of adopting this technology. To address calls for more holistic assessments of the effectiveness and environmental implications of MCS, this exploratory research developed the first comprehensive cradle-to-grave life cycle assessment (LCA) of the “grow nearshore, sink offshore” MCS strategy in Northern Europe using Saccharina latissima. In addition to evaluating climate change impacts, the assessment quantified impacts on ecosystem quality, human health, and natural resource scarcity, while sensitivity analyses were performed to assess the influence of seven key parameters, i.e., transportation distance, biomass yield, carbon/nutrient leakage, future background conditions, seeding technique, cultivation line material, and characterisation method. Our findings suggest that MCS could, under the modelled conditions, potentially function as negative emissions technology (NET), yielding a climate mitigation potential of 227 kg CO2-eq per tonne of CO2 durably sequestered. At the same time, the climate change and eutrophication benefits related to this technology come paired with estimated net environmental burdens to ecosystem quality (2.03 x 10-6 species.yr), human health (1.40 x 10-3 DALYs), and natural resource scarcity (83.9 USD 2013) for every tonne of CO2 durably sequestered. Furthermore, offshore transportation, carbon/nutrient leakage, cultivation infrastructure, and electricity usage during hatchery operations were found to be the dominant environmental hotspots, while sequestration durability as well as biomass yields present the largest uncertainties regarding MSC’s environmental performance. Given the extent of these uncertainties, as well as critical shortcomings in current LCIA methods and the limited estimated sequestration efficiency, large-scale MCS deployment remains difficult to justify. ... Read more

This thesis combines a substance-based Material Flow Analysis (MFA) of carbon in the EU economy with a systematic mapping of EU carbon-related policies to assess how well policies align with physical carbon flows. The analysis shows that EU carbon governance is heavily concentrated at the emissions stage, where major fossil and mineral emission flows are covered by multiple regulations, while upstream stages, trade, and material stocks receive far less attention. In particular, fossil fuel imports represent the largest carbon inflow but are not subject to carbon-specific regulatory criteria. The study concludes that EU carbon policies are structurally biased toward downstream emissions rather than carbon flows across the full life cycle, and recommends extending carbon intensity criteria to fossil fuel imports to improve policy coherence and completeness. ... Read more

Negative emission technologies aim to remove historic CO₂ from the atmosphere. Bioenergy with carbon capture and storage (BECCS) is regarded as a possible negative emission technology. This thesis aims to study the technological and economic feasibility of implementing BECCS in the cement industry. Four different types of biomass - rice husk pellets, wood pellets, sewage sludge, and municipal solid waste were chosen to substitute 30% of the coal in a model of a European cement plant. With an emphasis on retrofitting, three CO₂ capture technologies, absorption using monoethanol amine (MEA), calcium looping (CaL) based capture, and oxyfuel combustion capture were chosen. This thesis compares the techno-economic performance of the BECCS technologies in a cement plant using the key performance indicators (KPIs) of specific primary energy consumption per CO₂ avoided (SPECCA), cement production costs and costs of CO₂ avoided. Mass balance results and estimates of capital and operating expenses were used to calculate the KPIs. The parameters for each biomass-CO₂ capture combination are compared to each other and compared to the reference value of a cement plant which uses 100% coal without CCS. The results were subjected to sensitivity analysis. CO₂ accounting was performed for a defined boundary to estimate the carbon footprint of the BECCS technologies. The BECCS technologies studied have a lower rate of cement production as a result of co-firing biomass in existing boilers. This can be attributed to the low calorific value of biomass. Of the three CO₂ capture technologies, oxyfuel combustion capture is the least energy consuming option (1.8 MJ/t_CO2, with wood pellets) and the highest range of SPECCA is visible in the case of MEA (8.6 MJ/t_CO2, with municipal solid waste). The cement production costs increase by 42 to 89% compared to the costs without CO₂ capture. The cost of CO₂ avoided is between 45 €/t_CO2 (wood pellets with oxyfuel) to a higher range of 96 €/t_CO2 (sewage sludge with MEA). The variation in costs is significantly affected by the type of biomass used. CaL technology has a moderate performance in energy consumption and costs. SPECCA obtained for CaL process is in the range of 4.1 to 4.4 MJ/t_CO2 and the cost of CO₂ avoided is in the range of 57 to 74 €/t_CO2. CaL also entails the highest CO₂ capture rates, in comparison with MEA and oxyfuel technologies. In terms of total CO₂ emissions avoided, CaL based CO₂ capture gives the highest CO₂ avoided for the system boundary defined. Therefore, when the CO₂ removed from the atmosphere through the growth of biomass is included, the net CO₂ emissions are the least for CaL capture technology. The reason is the additional thermal energy requirements for the retrofitted CaL process units, which are met with 100% biomass. Although theoretically, a net negative value of CO₂ emissions was visible in the case of CaL, it must be noted that upstream process emissions are not included. But in practice, it is still unclear as to whether negative emissions are attainable with the information at hand. ... Read more