Input-output analysis for use in life cycle assessment: introduction to regional modelling

The objective of this thesis is to study the combination of environmental Input-Output (IO) models with Life Cycle Inventory (LCI) into a common framework which allows for regional/national environmental analyses meanwhile conserving process details. Our results show that this is possible by "adapting" the two methods: compiling LCI in matrix form and disaggregating as much as possible the IO tables. Given the poor data availability for detailed analyses at regional/national level, the results of this work suggest starting with a "traditional" IO analysis together with a Structural Path Analysis to identify the most polluting sectors and the paths through which the pollution is propagated. For the identified most polluting sectors, LCA data should be collected and fed into a tiered-hybrid IO-LCA model which gives the regional picture meanwhile conserves process details

Using life cycle assessments to guide reduction in the carbon footprint of single-use lab consumables

Scientific research pushes forward the boundaries of human knowledge, but often at a sizable environmental cost. The reliance of researchers on single-use plastics and disposable consumables has come under increased scrutiny as decarbonisation and environmental sustainability have become a growing priority. However, there has been very little exploration of the contribution of laboratory consumables to ‘greenhouse gas’ (GHG) carbon emissions. Carbon footprint exercises, if capturing consumables at all, typically rely on analyses of inventory spend which broadly aggregate plastic and chemical products, providing inaccurate data and thus limited insight as to how changes to procurement can reduce emissions. This paper documents the first effort to quantify the carbon footprint of common, single-use lab consumables through emission factors derived from life cycle assessments (LCAs). A literature review of LCAs was conducted to develop emission factors for lab consumables, considering the emission hotspots along each product’s life cycle to identify where emission reduction policies can be most effective. Results can be used as inputs for lab practitioners seeking to understand and mitigate their carbon footprint

A deep dive into the modelling assumptions for biomass with carbon capture and storage (BECCS) : A transparency exercise

This work was supported by the UK Energy Research Council (UKERC)-funded project ‘Assessing potential, feasibility and impacts of Bioenergy with CCS (BECCS) in the UK (Access-BECCS)’. We are very grateful to our anonymous reviewers for their constructive feedback which helped us to improve the manuscript.Peer reviewedPublisher PD

A Review of Criticisms of Integrated Assessment Models and Proposed Approaches to Address These, through the Lens of BECCS

Peer reviewedPublisher PD

Bringing value to the chemical industry from capture, storage and use of CO2: A dynamic LCA of formic acid production

Low carbon options for the chemical industry include switching from fossil to renewable energy, adopting new low-carbon production processes, along with retrofitting current plants with carbon capture for ulterior use (CCU technologies) or storage (CCS). In this paper, we combine a dynamic Life Cycle Assessment (d-LCA) with economic analysis to explore a potential transition to low-carbon manufacture of formic acid. We propose new methods to enable early technical, environmental and economic assessment of formic acid manufacture by electrochemical reduction of CO2 (CCU), and compare this production route to the conventional synthesis pathways and to storing CO2 in geological storage (CCS). Both CCU and CCS reduce carbon emissions in particular scenarios, although the uncertainty in results suggests that further research and scale-up validation are needed to clarify the relative emission reduction compared to conventional process pathways. There are trade-offs between resource security, cost and emissions between CCU and CCS systems. As expected, the CCS technology yields greater reductions in CO2 emissions than the CCU scenarios and the conventional processes. However, compared to CCS systems, CCU has better economic potential and lower fossil consumption, especially when powered by renewable electricity. The integration of renewable energy in the chemical industry has an important climate mitigation role, especially for processes with high electrical and thermal energy demands.The authors are grateful for the funding of the Spanish Ministry of Economy and Competitiveness through the Projects CTM2016-76176-C2-1-R (AEI/FEDER, UE) and CTQ2016-76231-C2-1-R (AEI/FEDER, UE). The UCL team would like to acknowledge funding from the UK Natural Environment Research Council through the project Comparative assessment and region-specific optimisation of GGR, NERC Reference: NE/P019900/1. Rubén Aldaco thanks the Ministry of Sciences, Innovation and Universities of Spanish Government for their financial support via the research fellowship Salvador de Madariaga Program (PRX18/00027)

Regionalized strategies for food loss and waste management in Spain under a Life Cycle thinking approach

Food loss and waste (FLW) has become a central concern in the social and political debate. Simultaneously, using FLW as a bioenergy source could significantly contribute to closing the carbon cycle by reintroducing energy into the food supply chain. This study aims to identify best strategies for FLW management in each of the 17 regions in Spain, through the application of a Life Cycle Assessment. To this end, an evaluation of the environmental performance over time between 2015 and 2040 of five di erent FLW management scenarios implemented in a framework of (i) compliance and (ii) non-compliance with the targets of the Paris Agreement was performed. Results revealed savings in the consumption of abiotic resources in those regions in which thermal treatment has a strong presence, although their greenhouse gas (GHG) emissions in a scenario of compliance with climate change targets are higher. In contrast, scenarios that include anaerobic digestion and, to a lesser extent those applying aerobic composting, present lower impacts, including climate change, suggesting improvements of 20-60% in non-compliance and 20-80% in compliance with Paris Agreement targets, compared to the current scenarios.This research was funded by the Spanish Ministry of Science and Competitiveness, grant number CERES-PROCON Project CTM2016-76176 (AEI/FEDER, UE) and KAIROS-BIOCIR Project PID2019-104925RB (AEO/FEDER, UE)

Exploring the possibility space: taking stock of the diverse capabilities and gaps in integrated assessment models

Abstract Integrated assessment models (IAMs) have emerged as key tools for building and assessing long term climate mitigation scenarios. Due to their central role in the recent IPCC assessments, and international climate policy analyses more generally, and the high uncertainties related to future projections, IAMs have been critically assessed by scholars from different fields receiving various critiques ranging from adequacy of their methods to how their results are used and communicated. Although IAMs are conceptually diverse and evolved in very different directions, they tend to be criticised under the umbrella of ‘IAMs’. Here we first briefly summarise the IAM landscape and how models differ from each other. We then proceed to discuss six prominent critiques emerging from the recent literature, reflect and respond to them in the light of IAM diversity and ongoing work and suggest ways forward. The six critiques relate to (a) representation of heterogeneous actors in the models, (b) modelling of technology diffusion and dynamics, (c) representation of capital markets, (d) energy-economy feedbacks, (e) policy scenarios, and (f) interpretation and use of model results.</jats:p

Sustainability of bioenergy – mapping the risks and benefits to inform future bioenergy systems

Bioenergy is widely included in energy strategies for its GHG mitigation potential. Bioenergy technologies will likely have to be deployed at scale to meet decarbonisation targets, and consequently biomass will have to be increasingly grown/mobilised. Sustainability risks associated with bioenergy may intensify with increasing deployment and where feedstocks are sourced through international trade. This research applies the Bioeconomy Sustainability Indicator Model (BSIM) to map and analyse the performance of bioenergy across 126 sustainability issues, evaluating 16 bioenergy case studies that reflect the breadth of biomass resources, technologies, energy vectors and bio-products. The research finds common trends in sustainability performance across projects that can inform bioenergy policy and decision making. Potential sustainability benefits are identified for People (jobs, skills, income, energy access); for Development (economy, energy, land utilisation); for Natural Systems (soil, heavy metals), and; for Climate Change (emissions, fuels). Also, consistent trends of sustainability risks where focus is required to ensure the viability of bioenergy projects, including for infrastructure, feedstock mobilisation, techno-economics and carbon stocks. Emission mitigation may be a primary objective for bioenergy, this research finds bioenergy projects can provide potential benefits far beyond emissions - there is an argument for supporting projects based on the ecosystem services and/or economic stimulation they may deliver. Also given the broad dynamics and characteristics of bioenergy projects, a rigid approach of assessing sustainability may be incompatible. Awarding ‘credit’ across a broader range of sustainability indicators in addition to requiring minimum performances in key areas, may be more effective at ensuring bioenergy sustainability

Structural decomposition analysis and input-output subsystems: Changes in CO2 emissions of Spanish service sectors (2000-2005)

The analysis of gas emissions by an input-output subsystem approach provides detailed insight into pollution generation in an economy. Structural decomposition analysis, on the other hand, identifies the factors behind the changes in key variables over time. Extending the input-output subsystem model to account for the changes in these variables reveals the channels by which environmental burdens are caused and transmitted throughout the production system. In this paper we propose a decomposition of the changes in the components of CO2 emissions captured by an input-output subsystems representation. The empirical application is for the Spanish service sector, and the economic and environmental data are for years 2000 and 2005. Our results show that services increased their CO2 emissions mainly because of a rise in the emissions generated by non-services to cover the final demand for services. The decomposed effects show a decrease in CO2 emissions due to technological changes between 2000 and 2005 compensated by an increase in emissions caused by the rise in final demand of services. Finally, large asymmetries exist not only in the quantitative changes in the CO2 emissions of the various services but also in the decomposed effects of these changes.Structural decomposition analysis Input-output subsystems CO2 emissions Service sector