More than 6% of global carbon dioxide emissions are caused by freight transport by road dominating emissions from the freight transport sector. To keep climate targets in reach, a rapid decarbonisation is necessary, while holistically considering trade-offs with other environmental impacts. This study compares the environmental impact profiles of road freight transport to the alternative via rail, under different prospective scenarios for the transport fleets and the socio-economic landscape in 2050, using prospective Life Cycle Assessment (pLCA). To do so the database ecoinvent v3.9.1 is systematically modified according to scenarios of the Integrated Assessment Model (IAM) REMIND, using the Python library premise. The Life Cycle Impact Assessment (LCIA) is performed in ActivityBrowser (AB) using the impact assessment method Environmental Footprint (EF) v3.1. Results show that
all environmental impacts categories across scenarios are significantly lower for rail than for road freight transport, due to the higher energy and material efficiencies of trains. Depending on the scenario and year, relative climate change impacts per tonne kilometre (tkm) by rail freight transport only make up between 15-26% of the impacts from road freight transport. Absolute climate change impacts can be reduced with a higher share of freight transport by
rail, decreased absolute freight transport growth, and increased electrification of the vehicle fleets, while the later increases most impact category results if applied to lorries.

As aviation accounts for 13.4% of the transport sector's emissions and 3.6% of all human greenhouse gas (GHG) emissions, the need for a sustainable bio-based industry arises. Meeting the growing demand for air travel requires a shift towards more sustainable alternatives, particularly in reducing fuel demand and emissions. Innovations such as weight reduction through bio-sourced materials, notably mycelium-based composites (MBCs), are promising. MBCs are known for their biodegradability, low energy consumption, and versatile applications, including packaging, furniture, fashion, and building materials, but also thermally and acoustically insultating properties that enable their use in the aerospace industry. This thesis focuses on adopting MBCs for non-structural purposes in aircraft cabin interiors. Despite their technological potential, early-stage development and limited data constrain the assessment of MBCs' environmental effects. The project aims to what are the future environmental impacts of producing MBCs at industrial production levels for aircraft interior applications, and how do they compare to conventional alternative materials.
To address this question, the project employed a Prospective Life Cycle Assessment (pLCA), offering a systematic assessment of the environmental impacts despite incomplete information. This study is conducted through two LCA phases designed to comprehensively evaluate the environmental impact of integrating MBCs. The first phase, "intratechnology comparison" focused on understanding the environmental implications of scaling up MBCs production from the laboratory to an industrial level. This phase also assessed the environmental impact of the MBCs material itself. The second phase, "intertechnology comparison" evaluated the environmental impact of an aircraft interior partition composed of MBCs and Scalmalloy compared to a conventional Nomex core sandwich partition. This comparative approach provided insights into the potential environmental benefits of using MBCs in aviation.
The process was divided in: (1) analyzing the current production of MBCs at the laboratory scale to establish the basis for modeling the emerging technology, (2) scaling up the technology to industrial production scenarios, (3) performing a pLCA to comprehensively assess the environmental impact of MBCs, considering uncertainties inherent in the early-stage development of this technology.
Key findings from this study highlight the potential of MBCs. The upscaled production of MBCs is expected to have lower emissions than lab-scale production. Current manufacture remains energy-intensive. In their direct application as non-structural components in aircraft cabin interiors, MBCs showcase advantages over conventional materials due to their lightweight nature, which benefits the use phase. However, the upscaled manufacturing process does not necessarily surpass those of conventional materials, such as the Nomex core sandwich partition, indicating hotspots that need to be addressed.
Additional scenario assessments, recyclability and energy carriers for use phase and manufacturing, were considered. The recyclability of MBCs may offer additional environmental benefits, but careful energy management is crucial to maximize these advantages. The energy carriers for the production significantly impact the environmental impact. Additionally, the lightweight nature of MBCs remains an advantage even with the transition to more decarbonized fuels.
The findings emphasize the importance of using LCA from the early design phase and iteratively as technology develops to achieve optimal results. The pLCA of MBCs offers valuable insights into their environmental impact and guides research and development efforts, helping to make informed decisions about their use in aircraft cabin interiors and further applications.

Through exploratory scenario development, this study delves into the environmental impacts of European commercial aviation. Climate targets and the adoption of alternative aviation fuels (AAF) following ReFuelEU Aviation are assessed, considering e-fuel produced from direct air capture (DAC) and hydrogen aircraft. A novel method is applied, combining the generation of prospective life cycle inventories based on integrated assessment models with technology forecasting, system dynamics, and scenario development. This enables reflection on not only aircraft performance, but also fuel production, aircraft manufacturing, and fleet dynamics. Although there are limitations, including the relatively simple approach to system dynamics and limited data availability, clear conclusions can be drawn. Even for high-growth trajectories of air traffic, the total fuel demand of aviation could stagnate by 2035 under highly ambitious circumstances. Lower air traffic would require less ambitious circumstances. Combined with the reduced impact of AAF on aviation-induced cloudiness modelled here, the radiative forcing associated with aviation could reach a peak by 2050. However, the current scope of ReFuelEU Aviation does not prevent this peak from being eclipsed again by 2070. To prevent this, the mandate for a 70% share of AAF by 2050 should be followed up with a mandate for a 100% share. Thereby, warming neutrality is within reach – provided the necessary technologies can be implemented at scale. Hydrogen propulsion makes more efficient use of resources than e-fuel does, which is relevant for some impact categories, but less so for climate change as assessed here. When considering the magnitude of radiative forcing, present projections fall short. Estimating a budget of CO2 emissions through a grandfathering approach of the targets set by ICAO and IATA, the budget is exceeded by 2070, even with the most optimistic technological advancements. Critical here is the high use of fossil fuel leading up to 2035, for which there are no timely technological solutions. Lacking offsetting opportunities that are reliable, large-scale, and long-term, the only option is to restrict the volume of air traffic. Reducing traffic to 70% of the 2019 passenger-kilometers can be sufficient to respect the CO2 limit, even without optimistic developments in aircraft technology. This challenges conventional narratives, which advocate against demand management, claiming this would limit technological innovation. Thereby, evidence is created in support of the degrowth discourse which has gained momentum in recent decades. To ensure that aviation can provide long-term societal benefits, near-future flight activity must be redistributed to future generations. Given the boundaries and uncertainties of the presented scenarios, a much-needed discussion is encouraged: what share of global environmental limits is aviation – and within that, European aviation – entitled to?

Emerging in the domain of composite manufacturing, thermoplastic polymers can enable the reduction of process times, costs, and waste. In this study, lifecycle assessment (LCA) is used to evaluate a design for a carbon fibre-reinforced thermoplastic (CFRTP) wing rib, made from carbon fibre and polyetherketoneketone (CF/PEKK). The CF/PEKK rib is compared to several hypothetical alternatives, considering autoclave and resin transfer moulding of CF/epoxy and milled aluminium alloy.

The comparison uses novel and state-of-the-art techniques. Using scenario analysis, several perspectives are considered: recyclability, mass-induced energy demand, and alternative energy carriers. The analysis of energy carriers and end-of-life processes incorporates prospective methods to explore the effects of the energy transition. Across these scenarios, it was found that, when there is a mass difference among alternatives of 2% or more, the lighter alternative will be preferred, regardless of other factors. Through sensitivity analyses, potential was found for this margin to grow to 3% under extreme conditions, and to around 5-10% when shifting the whole lifecycle into the future. When dealing with smaller mass differences, material production and manufacturing waste become distinguishers of environmental performance.

These insights are valuable when exploring novel materials and manufacturing methods for commercial aviation. The approach defined in this thesis can be extended to any other application which has a lightweighting imperative, such as automotive, shipping, rail, or wind turbines. Building on this thesis, guidance can be provided on how and where to apply novel materials across multiple product lifecycles.

Aiming to comply with the Paris Agreement, the reduction of Europe’s GHG emissions in the energy sector is a must. Due to the intermittency of renewable sources, energy storage technologies are essential to this plan. Offshore Low Head Pumped Hydro Storage (LH PHS) is presented as an alternative to partly solve this problem. Considering that its infrastructure entails a reservoir of a 5km diameter ring in the middle of the sea and needs millions of tonnes of concrete, sand, granite and steel among other materials for its construction; environmental concerns arouse, which this report aims to address.
Information from the Alpheus project about the engineering requirements for an offshore LH PHS plant is used, following ISO 14044 Life Cycle Assessment (LCA) methodology. In this study, the construction, maintenance and operation of an offshore LH PHS plant are assessed, focusing on Global Warming Potential (GWP), Water Use Depletion Potential (WUDP) and Abiotic Depletion Potential for Elements (ADP-E). This is studied with and without the input of electricity, sourcing it from wind or from the Dutch grid mix. Moreover, these results are compared with Lithium iron phosphate (LFP) Batteries and for Wind-Green Hydrogen.
For the construction, operation and maintenance of the LH PHS plant, it is estimated that the emissions would reach 2.8Mt of CO2-eq, 601 million m3 of water and 140.2t of Sb-eq. These emissions are mainly shared between civil and electromechanical infrastructure, the former has more relevance for GWP with almost 56% of the emissions whereas the latter reaches 69% for WUDP and 98% for ADP-E. When electricity is incorporated into the equation and these emissions are translated per kWh, emissions from the generation of electricity exceed 2.4, 5.6 and 1.8 times those emissions from the infrastructure for GWP, WUDP and ADP-E. When comparing LH PHS with other technologies using wind as the only source of electricity production, LFP Batteries outperform LH PHS most of the time for GWP and WUDP, whereas LFP are consistently the worst performer for ADP-E. LH PHS always performs better than Green Hydrogen in all three impact categories.
If emissions reductions are to be achieved in the LH PHS case, the focus should be put on the electricity side: improving the efficiency of the plant, storing only clean energy and improving the performance of renewables. Finally, there are other considerations to LH PHS implementation that should be taken into account that are not assessed in this report. The use of materials and their circularity must be considered, as well as the social ramifications of projects like PHS and mining materials for Li-ion Batteries. Furthermore, impacts on biodiversity must be addressed and its damages should not only be minimized but restored or even improved.

The global production of textiles carries a significant share in global greenhouse gas emissions, with a demand projected to grow. Especially for scope 3 emissions, materials play a significant role, with polyethylene terephthalate (PET) as a dominating fibre material with unique properties. Virgin PET based on fossil oil as the conventional option is non-renewable, not aligning with a sustainable future supply route. Alternative drop-in feedstock options for PET are biobased or recycled. Biobased PET has the potential for an emission reduction, but that is not automatically the case. Also there is a trade-off with a worse performance in other impact categories because of the agricultural production. With recycled PET, there are mechanical and chemical recycling options. Mechanical recycling for fibres is feasible and established as open-loop recycling from bottles. For mechanical recycling from textiles, a blend with virgin PET becomes necessary to maintain the required quality. Chemical recycling is more promising for closed-loop recycling from textile waste, but infrastructure and design barriers are current limitations for its expansion. Because these PET sourcing routes come with different trade-offs and barriers, it is reasonable to explore other routes as well, such as basic oxygen furnace (BOF) gas fermentation and compare them with the alternatives.
In this study, Life Cycle Assessment (LCA) was conducted to determine the climate change impact of BOF gas fermentation-based PET compared to mechanically recycled and fossil-based PET. Then, the results were also compared to literature values for biobased and chemically recycled PET, embedding the results in the context of alternative sourcing routes for PET in the textile industry. In the focus technology of this study, feedstock gases rich in carbon are fermented into ethanol by microorganisms. Through several intermediates, monoethylene glycol (MEG) is made as one of the two main components of PET. Together with pure terephthalic acid (PTA), it is polymerised into PET. Several carbon-rich feedstock gases such as syngas from biomass or wastes, but also reformed natural gas have been explored in previous research and development. However, the commercially available option is to use off-gas from the steel industry from the BOF. Therefore, the examined feedstock in this LCA is BOF gas with a composition of 85% CO and 15% CO2.
With a climate change impact of 4.95 CO2eq / kg PET, fermentation-based PET had the highest impact within the LCA model results of this study, followed by virgin PET (2.93 kg CO2 eq per kg PET) and then mechanically recycled PET (1.05 kg CO2 eq per kg PET). Biobased PET literature values ranged between comparable impacts to mechanically recycled PET up to values higher than all other investigated sourcing alternatives. Chemically recycled PET had an impact between mechanically recycled PET and virgin PET. In terms of environmental contributions, for all alternatives the major share of greenhouse gas emissions was from fossil CO2 (around 80%). Technosphere contribution hotspots were the carbon dioxide released during the fermentation and high voltage electricity production, mainly for the conditioning of the feedstock gas (compression and cooling). Also the provision of the virgin PTA component had a considerable contribution (1.11 CO2eq / kg PET).
Under the current global electricity mix, the gas fermentation technology was concluded to not be an advisable alternative to reduce greenhouse gas emissions. A combination of a best-case renewable electricity scenario, a substitution of the missing energy from the BOF gas in the steel process with wind energy instead of natural gas and an orange-peel based PTA sourcing route could reduce the climate change impact down to be comparable to mechanically recycled PET. However, that result is only valid if the emission credit assumption for the avoided emissions in the steel process holds. Otherwise, the gas fermentation technology emits more greenhouse gas emissions than both conventional alternatives, even under the best-case scenario.

This study builds upon the existing work on futurizing the ecoinvent database at the service of the prospective LCA method that requires a temporally matched foreground and background system. It is a first effort in modelling future scenarios of Industrial Process Heat (IPH) generation using projections from the IMAGE Integrated Assessment Model (IAM) following the SSP2-baseline, SSP2-RCP2.6 and SSP2- RCP1.9 scenarios from 2020 to 2050. These scenarios are then implemented in the ecoinvent database (version 3.8, cut-off) and used to quantify the environmental impacts of generating 1MJ of IPH across four markets in twenty-six regions for three different scenarios. The markets under study are chemicals, food and tobacco, pulp and paper, while the rest of the sectors without cement and steel are grouped under the “other industries” category, as per IMAGE classification. We quantify and analyze the climate change impact and cumulative decarbonization potential of the future IPH generation markets across sectors and regions. Furthermore, we quantify their performance across fifteen additional impact categories to check for potential burden shift. On top of IMAGE projections, we also explore whether coupling CHP with CCS impacts our results.

By 2050, even in the best-case scenario (SSP2-RCP1.9), fossil fuels are still expected to be responsible for the generation of 48% of the global IPH demand for food and tobacco, 51.4% for the Other industries category, 64% for chemicals and 88% for pulp and paper. Nevertheless, heat from coal is expected to reduce its share in the global IPH generation market mixes in a range of -56% to -95% across sectors, being one of the main reasons why climate change impact shows a decrease in the range of 31-60% across sectors when compared to the baseline (pulp and paper: -31%, food and tobacco: -57%, Other industries: -60%, chemicals: -34%).

By 2050, in the best-case scenario, the direct combustion of biomass is expected to supply 25% of the global IPH demand for food and tobacco and 20.8% of the global IPH demand for other industries category. Biofuels are expected to provide 1/3 of the IPH demand in the chemicals sector with little impact on climate change but at the cost of contributing with a significant share in other environmental impact categories such as marine eutrophication (63.4%), terrestrial eutrophication (57.8%), non-carcinogenic human toxicity (70.2%), land use (98%), water use (91.8%) and minerals depletion (80.6%). Electrification is expected to take a more prominent role mainly in food and tobacco and other industries sectors offsetting emissions by -9.07% and -13.7% but at the cost of increasing the ionising radiation impact from electricity production.

The results from the other environmental categories highlight a decrease in impacts across most of the environmental impact categories except for land use, ionising radiation, water use and minerals depletion, which emphasized the potential burden shift that the decarbonization efforts may cause.



Our results also show that the most optimal outcomes are received when the decarbonization of the heat supply is combined with the demand reduction. The demand reduction across sectors as well as the respective decarbonization of IPH generation market mixes, results in a cumulative decarbonization potential of 85.78 Gt CO2-eq. (RCP2.6) and 105.29 Gt CO2-eq. (RCP1.9).

Implementing CHP with CCS is beneficial to climate change but may decline the improvement potential for many impact categories compared to when CHP is not coupled with CCS.

By 2050, the highest emitters of CO2-Eq. emissions are the regions that drive the global IPH demand: China (CHN), India (INDIA), Middle East (ME), USA and Western Europe (WEU), responsible for at least 70% of the global carbon footprint across scenarios.

This study is the first trial of this sort, and as a consequence, there is a lot of potential for improvement of future IPH generation scenarios, which requires further research for the following aspects:

• Enriching IMAGE projections with shares of conversion technologies for IPH generation
• Enriching the ecoinvent database with lifecycle inventories of cleaner heat generation technologies
• Enriching IMAGE with projections for renewable heat sources and cleaner fuels for IPH generation
• Enriching IMAGE scenarios with projections on GHG emissions reductions for IPH generation as well as projections on CCS implementation for IPH generation
• Disaggregating the “Other Industries” category
• Improving ecoinvent lifecycle inventories for the manufacturing processes in the most carbon- intensive industries that do not disaggregate fuels used for IPH generation versus feedstocks

Considering the data scarcity, time limitations and unresolved uncertainties, it is essential to treat these results as potential future trends rather than in absolute terms.

Using the IEA Ammonia Roadmap aligned with the IMAGE electricity scenarios, an extensive database was produced allowing for prospective LCAs across three storylines from 2020 to 2050 (SSP2-Base, SSP2-RCP26, SSP2-RCP19). The scenarios correspond respectively to 3.9, 2.0, and 1.5°C of global warming in 2100 (vs. pre-industrial levels). Regionally, China produces the largest volume of ammonia as well as the ammonia with the largest climate change impact, due to the dominance of coal gasification technology. To meet 1.5°C of warming (the most sustainable scenario) a global decrease of fossil-based ammonia is needed. For many regions, electrolysis (yellow) ammonia becomes the technology with the lowest global warming potential by around 2045 in the RCP26 storyline and 2035 in RCP19. Until the regional electricity mixes are cleaner, steam reforming, steam reforming with carbon capture and storage, or methane pyrolysis offer lower emission options. However, electrolysis using on-site or designated renewable energy can create emission-free green ammonia, without waiting years for a cleaner regional grid. This means that electrolysis is the best choice for new plants if a producer is not making urea on-site (or has an alternative source of carbon dioxide if they are). Reduction in urea demand will be important for reducing reliance on steam reforming and coal gasification, and a swift uptake of electrolysis with designated renewables must be the focus. However, burden shifting associated with the dominance of renewable electricity systems and bioenergy carbon capture and storage in the RCP19 scenario must be taken into account.

Aviation is an important sector and one of the key contributors to today’s economy. With a forecasted annual growth rate of 4.4%, the sector is expected to expand even more in the coming years. This expansion is however followed by the environmental burdens aviation causes to the environment. Following the anticipated growth of the aviation industry, action to avoid the same trend in emissions is critical. Following the recent introduction of circularity in inflight services airlines are taking measures often labeled as sustainable, seeking ways to reduce their carbon footprint. It is important to evaluate whether these measures improve the environmental performance of inflight services or not. To achieve that, the cradle-to-grave approach of the Life Cycle Assessment
(LCA) method is recommended. Furthermore, there is little to no research on quantifying the overall climate impact of inflight services. This thesis is therefore aiming to fill this research gap by conducting an LCA on inflight services offered to passengers and the research question is formed as: “How do inflight services, and measures intending to reduce their climate impact, perform in terms of
carbon footprint and to what extent do they enable sustainability?”. Two baseline cases were evaluated to answer the research question, a short-haul, and a long-haul flight, representing conventional inflight service practices. For each case, five scenarios were constructed based on measures aiming to reduce the carbon footprint of inflight services, namely single-use plastic reduction, food waste reduction, lightweight materials introduction, carbon offsetting, and a combination of all the measures. The analysis aimed to quantify the impact
of inflight services, in terms of contribution to climate change, and compare the applied measures to the baseline cases, assessing whether they enable sustainability or not. Overall, the study can conclude that the evaluated inflight service measure scenarios performed better than the business-as-usual inflight service practices. The total carbon footprint of inflight services per passenger on a short-haul flight was calculated as 10.9 kg CO2-Eq and on a long-haul flight as 50.2 kg CO2-Eq. The combined measures carbon footprint reduction potential could reach the impressive 96% for a long-haul flight and 89% for a short-haul flight reduction. Most of this reduction is mainly attributed to carbon offsetting, 82% for the long-haul flight and 69% for the short-haul flight. The second best-performing scenario was the lightweight materials measure which could reduce carbon footprint by 13% and 19% for the long-haul and the short-haul flight respectively. Single-use plastic and food waste reduction measures did not exceed a 0.4% reduction of the impact. Although carbon emissions of inflight services entail a small fracture of the overall aviation carbon footprint, the studied measures can contribute to notable environmental impact reductions with immediate results.