J.M. Allwood’s research while affiliated with University of Cambridge and other places

This anthology brings together a diversity of key texts in the emerging field of Existential Risk Studies. It serves to complement the previous volume The Era of Global Risk: An Introduction to Existential Risk Studies by providing open access to original research and insights in this rapidly evolving field. At its heart, this book highlights the ongoing development of new academic paradigms and theories of change that have emerged from a community of researchers in and around the Centre for the Study of Existential Risk. The chapters in this book challenge received notions of human extinction and civilization collapse and seek to chart new paths towards existential security and hope. The volume curates a series of research articles, including previously published and unpublished work, exploring the nature and ethics of catastrophic global risk, the tools and methodologies being developed to study it, the diverse drivers that are currently pushing it to unprecedented levels of danger, and the pathways and opportunities for reducing this. In each case, they go beyond simplistic and reductionist accounts of risk to understand how a diverse range of factors interact to shape both catastrophic threats and our vulnerability and exposure to them and reflect on different stakeholder communities, policy mechanisms, and theories of change that can help to mitigate and manage this risk. Bringing together experts from across diverse disciplines, the anthology provides an accessible survey of the current state of the art in this emerging field. The interdisciplinary and trans-disciplinary nature of the cutting-edge research presented here makes this volume a key resource for researchers and academics. However, the editors have also prepared introductions and research highlights that will make it accessible to an interested general audience as well. Whatever their level of experience, the volume aims to challenge readers to take on board the extent of the multiple dangers currently faced by humanity, and to think critically and proactively about reducing global risk.

The current decarbonization strategy for the steel and cement industries is inherently dependent on the build-out of infrastructure, including for CO2 transport and storage, renewable electricity, and green hydrogen. However, the deployment of this infrastructure entails considerable uncertainty. Here we explore the global feasible supply of steel and cement within Paris-compliant carbon budgets, explicitly considering uncertainties in the deployment of infrastructure. Our scenario analysis reveals that despite substantial growth in recycling- and hydrogen-based production, the feasible steel supply will only meet 58–65% (interquartile range) of the expected baseline demand in 2050. Cement supply is even more uncertain due to limited mitigation options, meeting only 22–56% (interquartile range) of the expected baseline demand in 2050. These findings pose a two-fold challenge for decarbonizing the steel and cement industries: on the one hand, governments need to expand essential infrastructure rapidly; on the other hand, industries need to prepare for the risk of deployment failures, rather than solely waiting for large-scale infrastructure to emerge. Our feasible supply scenarios provide compelling evidence of the urgency of demand-side actions and establish benchmarks for the required level of resource efficiency.

This paper presents a new methodology for cost- and carbon-optimal generation of multi-storey building designs. The methodology features algorithms for automatic optimised design of concrete, steel, and timber frames; established as well as novel decking technologies; and foundation options. Applying the methodology, we illustrate the potential carbon and cost savings unlocked by well-informed early-stage design decisions by means of two test cases: a simple rectangular building and another with more complex geometry. We show that the impact of early-stage design decisions such as column grid, site, frame material, and decking choice have much larger emission saving potential than the choice between optimisation objectives.

There is increasing concern that climate change poses an existential risk to humanity. Understanding these worst-case scenarios is essential for good risk management. However, our knowledge of the causal pathways through which climate change could cause societal collapse is underdeveloped. This paper aims to identify and structure an empirical evidence base of the climate change, food insecurity and societal collapse pathway. We first review the societal collapse and existential risk literature and define a set of determinants of societal collapse. We develop an original methodology, using these determinants as societal collapse proxies, to identify an empirical evidence base of climate change, food insecurity and societal collapse in contemporary society and then structure it using a novel-format causal loop diagram (CLD) defined at global scale and national granularity. The resulting evidence base varies in temporal and spatial distribution of study and in the type of data-driven methods used. The resulting CLD documents the spread of the evidence base, using line thickness and colour to depict density and type of data-driven method respectively. It enables exploration of how the effects of climate change may undermine agricultural systems and disrupt food supply, which can lead to economic shocks, socio-political instability as well as starvation, migration and conflict. Suggestions are made for future work that could build on this paper to further develop our qualitative understanding of, and quantitative complex systems modelling capabilities for analysing, the causal pathways between climate change and societal collapse.

We can’t wait for breakthrough technologies to deliver net-zero emissions by 2050. Instead, we can plan to respond to climate change using today’s technologies with incremental change. This will reveal many opportunities for growth but requires a public discussion about future lifestyles.

Copper contamination of end-of-life steel scrap is the main barrier to high-quality recycling. Preferential melting of copper from solid steel scrap is a potential extraction technique, which could be integrated into conventional scrap re-melting with little additional energy. However, previous investigations show removal of liquid copper is limited by its adherence to solid scrap. Preventing wetting between liquid copper and steel is essential to enable separation. The carbon content of steel, initial surface oxidation, and applied coatings effect wetting behavior, but have not been systematically studied. In this study, the individual and combined effects of these parameters on wetting behavior in an inert gaseous environment are observed with a heating microscope. Carbon content appears to be the most significant factor: blistering of the oxide scale on medium-carbon steels causes liquid copper to flow rapidly between the oxide and steel substrate. Liquid copper exhibited a stable droplet on low-carbon steel, regardless of the initial level of oxidation. The tested coatings did not consistently improve nonwetting behavior, but impaired the connection between the scale and steel substrate. This study confirms the potential of the preferential melting technique, but further investigation is needed to determine the most robust process conditions to handle diverse, fragmented scrap at an industrial scale.

The supply of end-of-life steel scrap is growing, but residual copper reduces its value. Once copper attaches during hammer shredding, no commercial process beyond hand-picking exists to extract it, yet high-value flat products require less than 0.1 wt pct copper to avoid metallurgical problems. Various techniques for copper separation have been explored in laboratory trials, but as yet no attempt has been made to provide an integrated assessment of all options. Therefore, for the first time, a framework is proposed to define the full range of separation routes and evaluate their potential to remove copper, while estimating their energy and material input requirements. The thermodynamic, kinetic, and technological constraints of the various techniques are analyzed to show that copper could be removed to below 0.1 wt pct with relatively low energy and material consumption. Higher-density shredding allows for greater physical separation, but requires proper incentivization. Vacuum distillation could be viable with a reactor that minimizes radiation heat losses. High-temperature solid scrap pre-treatments would be less energy intensive than melt treatments, but their efficacy with typical shredded scrap is yet unconfirmed. The framework developed here can be applied to other impurity-base metal systems to coordinate process innovation as the scrap supply expands.