• Energy Research

In this progress report on climate change, I examine the growing literature dealing with the proposal to engineer global climate through the deliberate injection of aerosols into the stratosphere. This is just one of a wide range of technology proposals to geoengineer the climate, but one in particular which has gained the attention of Earth System science researchers and which is attracting wider public debate. I review the current status of this technology by exploring a number of different dimensions of the proposal: its history and philosophical and ethical implications; how it is framed in public discourse and perceived by citizens; its economic, political and governance characteristics; and how the proposed technology is being researched through numerical modelling and field experimentation. Unlike many other geoengineering interventions, stratospheric aerosol injection has no additional societal co-benefits: its sole raison d’etre would be to offset planetary heating caused by rising concentrations of greenhouse gases. The deployment of such a technology would have profound implications for the view humans have of themselves in relation to the non-human world.

Abstract The IPCC's emissions scenarios form the basis for the majority of long-term climate change projections, including those of the current Fourth Assessment Report. The main characteristics of the IPCC's three scenario series – published in 1990, 1992 and 2000 – have changed significantly over time: titles, classification, assumptions and methods have all changed. This article analyses the evolution of the structure, description, process development and context of the IPCC's emissions scenarios, identifying the most important changes and their scientific and political causes. These changes are evaluated against the criteria of saliency, credibility and legitimacy. Our analysis indicates, first, enhanced credibility through an improved scenario construction methodology (multiple baseline scenarios; storylines), even though these achievements are diluted by particularities of the scenario approach used. Second, a reduced saliency through absence of titles, an inappropriate classification and the relatively high number of baseline scenarios, limits and weakens their wider applicability. These latter trends were due in part to concessions made to the intergovernmental nature of the construction process (trade-offs). The article concludes by proposing for the future the employment of a more formal qualitative construction approach as well as revisions to scenario labelling and classification practices.

International and national greenhouse gas emissions reduction goals implicitly rely in part on individuals undertaking voluntary emissions reductions through lifestyle decisions. Whilst there is widespread public recognition of climate change as an issue, there are many barriers – cognitive, psychological and social – preventing individuals from enacting lifestyle decarbonisation. More effective climate change communication approaches are needed which allow individuals to engage meaningfully with climate change, thus opening new prospects for lifestyle decarbonisation. This study presents an iconic approach to engagement, tested in the UK context, which allows individuals to approach climate change through their own personal values and experiences. The iconic approach harnesses the emotive and visual power of climate icons with a rigorous scientific analysis of climate impacts under a different climate future. Although some climate icons already exist – for example the Thermohaline Circulation shutdown – these ‘expert-led’ icons fail to effectively engage ‘non-experts’. We demonstrate that the non-expert-led iconic approach helps overcome some of the cognitive and affective barriers that impede action towards lifestyle decarbonisation.

This chapter traces the development of the western scientific understanding of climate change, from the eighteenth into the twenty-first centuries. This requires paying careful attention to the spatial, social and political relations of emerging scientific practices. The chapter shows how scientific knowledge about climate change has been profoundly enabled and shaped by the exercise of political power: by the rise of Empires, by the geopolitics of the Cold War and, in recent decades, by new transnational institutions of the United Nations. People, patronage and politics have interacted through sites of scientific knowledge production — glaciers, satellites, research ships, laboratories, computers, conference rooms and websites -- to establish climate change as a phenomenon knowable through science and hence predictable by science. Even in an era of extensive international and online scientific cooperation, ‘place’ is important for the making and transmitting of scientific knowledge claims about climate change. This is because of the influence of national state politics and cultural norms on scientific practices. The chapter shows that scientific knowledge about climate change is both political and geographical.

For proponents of the view that anthropogenic climate change will become a ‘threat multiplier’ for instability in the decades ahead, the Syrian civil war has become a recurring reference point, providing apparently compelling evidence that such conflict effects are already with us. According to this view, human-induced climatic change was a contributory factor in the extreme drought experienced within Syria prior to its civil war; this drought in turn led to large-scale migration; and this migration in turn exacerbated the socio-economic stresses that underpinned Syria's descent into war. This article provides a systematic interrogation of these claims, and finds little merit to them. Amongst other things it shows that there is no clear and reliable evidence that anthropogenic climate change was a factor in Syria's precivil war drought; that this drought did not cause anywhere near the scale of migration that is often alleged; and that there exists no solid evidence that drought migration pressures in Syria contributed to civil war onset. The Syria case, the article finds, does not support ‘threat multiplier’ views of the impacts of climate change; to the contrary, we conclude, policymakers, commentators and scholars alike should exercise far greater caution when drawing such linkages or when securitising climate change.

Abstract During its 20 years of publication, the journal Global Environmental Change has given visibility and coherence to the eponymous research paradigm. Global environmental research has brought forth new kinds of knowledge about the multi-scale interactions between physical and social dimensions of the environment. This essay reflects on some of the problems with making and governing these global kinds of knowledge, as suggested through the perspectives of a nascent geography of science. I use climate change – an emblematic theme of global environmental change research over the last 20 years – to examine three facets of the global environmental change paradigm: making global kinds of knowledge, globalising environmental values and the governance of knowledge-making. New global kinds of knowledge have gained power and visibility in contemporary scientific, public and political fora and yet such knowledge can be ‘brittle’, easily cracked and broken. A geography of global environmental change knowledge therefore demands we turn our attention away from the globalising instincts that so easily erase difference and collapse meaning, and instead concern ourselves with understanding the relationships between knowledge-making and human culture in evolving places. Only then will we recognise the ambiguities, voids and blind spots in our understanding of the world's complexity.

The IPCC has been successful at building its scientific authority but it will require institutional reform for staying relevant to new and changing political contexts. Exploring a range of alternative future pathways for the IPCC can help guide crucial decisions about redefining its purpose.