In 1980, the American editor of the Royal Swedish Academy of Sciences’ journal, Ambio, attended a conference where a speaker described the aftermath of nuclear war as “unimaginable.” Finding this assessment wanting, journalist Jeannie Peterson took it upon herself to assemble the scientific expertise
to determine more specifically the likely results of the outbreak of nuclear war. Hers was not simply an empirical exercise—“a realistic assessment of the possible human and ecological consequences of a nuclear war may help to deter such a catastrophe,” she began the subsequent special issue’s editorial. Accordingly, the advisory group she recruited included the special assistant for disarmament to the Swedish minister of defense, a physicist from the Manhattan Project who had founded the Pugwash Conference on Science and World Affairs, and another who had directed the Stockholm International Peace Research Institute.
Having provided a possible scenario of nuclear war to participating scientists, she and her advisors were stunned by findings that fire and smoke, not radioactive fallout, would have the most far-reaching effects. To describe the atmospheric aftermath of large-scale nuclear war, they coined the term “nuclear winter.”
Focusing on the South Pacific, this paper examines how the scientific and political debates over nuclear winter highlight the convergence of atmospheric anxieties in the late 1980s. Reactions to the nuclear winter theory not only presaged the divisiveness that would characterise political responses to anthropogenic climate change, but also set the scene for much closer attention to the earth’s changing temperature and vulnerability to human activity.

This paper examines how earth scientists and environmental historians engage with deep-time geological knowledge in response to contemporary climate and planetary challenges. Through interdisciplinary dialogue, we explore how the understanding of Gondwana — the great southern megacontinent — has evolved from a colonial-era geological concept to a crucial framework for interpreting planetary changes, past and present. While geological knowledge of Gondwana has traditionally circulated through standardised global channels (like plate tectonic models and museum collections), recent developments in open-source earth science tools and democratised data access are creating new opportunities for local knowledge production and adaptation, particularly outside of traditional centres of geological knowledge in Europe and North America.

Our conversation reveals how the tension between universal geological principles and local applications of earth science knowledge mirrors broader patterns in public science communication. Just as natural history museums worldwide display identical Gondwana fossils, open-source platforms now enable globally consistent but locally implementable earth science research. This tension between global and local knowledge becomes especially significant as communities worldwide grapple with climate change — a crisis that demands both universal scientific understanding and locally adapted solutions. By examining how geological knowledge of Gondwana is produced, circulated, and applied across different scales and contexts, we demonstrate how earth science can inform public understandings of planetary change while remaining responsive to local circumstances. Our interdisciplinary conversation offers insights into how scientific knowledge can be both globally coherent and locally relevant in addressing planetary-scale challenges.

Dr Sabin Zahirovic

In climate change research, the data is typically presented with line graphs that demonstrate change over time. Often, these graphs show sharp rises in temperature or greenhouse gas concentrations in the last century, such that the shape of a hockey stick emerges from the data. The public has likely encountered these graphs. They have appeared on the cover of Time. They’ve featured in museum exhibits the world over. They’ve been used in documentaries. Frequently, these graphs are accompanied with some explanation of the data that underlies them. This means that depictions of climate proxies such as tree rings, ice cores, and pollen are found alongside these graphs in public outreach about climate change.

This paper explores this curious connection between data and depiction. Why, unlike instrumental data, have proxies become such an important part of public imaginaries about climate change? By following the intersection of proxy data and graphs in public-facing places, this paper seeks to explain why proxy data is treated differently than other data. I argue that proxies fulfill three roles that the graphs alone cannot. First, they helped make climate change more tangible (even as scientists admitted that climate change was difficult to see). Second, proxies made climate science more trustworthy (even as scientists repeated that proxy data were less robust than instrumental data). Last, proxies localized climate change (even as scientists represented climate change as global). By exploring these tensions, the paper aims to understand the production of proxies in public engagement with climate change.