he wavering, saw-toothed plot of atmospheric carbon dioxide levels pushed determinedly over the threshold of 400ppm, tracing a line from the global space of the atmosphere to the hermetic spaces of geoscientist Charles Keeling’s early CO2 observations. As one of millions of virtual witnesses to this traversal, I was reminded that Keeling’s deployment of his 5-litre flasks was not the first time that a glass orb had changed science and, with it, the world.

Charles Keeling began his work of estimating sky-bound CO2 by sampling the air with spherical glass flasks fitted with a tap to control the flow of atmospheric matter, and to transform the interminable flux of the troposphere into an abeyant, isolated segment of a much larger whole. The 17th century chemist Robert Boyle also dealt with questions “of how to put the air into abeyance, suspending its operations in order to see it, as it were from the outside, as an outside that was paradoxically enclosed conveniently in visible and manipulable interiors” (Connor, 2010: 26). Boyle resolved these challenges with his mechanical air pump, with which he inquired into the nature of a vacuum and the variability of air pressure. Blown glass enabled the enactment of a new experimental space where the effects of air on other types of matter could be observed, witnessed, and granted the status of positive knowledge. 

The original ‘Keeling Flask’, itself sealed in a glass case at the Science Museum, London. The flasks were wrapped in tape to guard against implosion after they were evacuated of air. Image reproduced from blogs.shell.com.

Like the observational spaces of Keeling’s spheres, Boyle’s experimental forms evolved in a complex relationship with the broader cultural milieu. Experimental knowledge-making, with its ‘invisible college’ of trustworthy witnesses and its lucid linguistic strategies which recapitulated the transparency of the air pump itself, was promoted as a model of calm, respectful collective reasoning which offered an alternative to the vehemence and antagonism of the concurrent restoration of the English monarchy. The epistemic and communicative strategies of the new experimentalists perhaps helped establish the primacy of the visual in Western political culture (Ezrahi, 1990), while capturing perfectly the notion that solutions to the problem of knowledge are found in solutions to the problem of social order (Shapin and Schaffer, 1985).

Like Boyle’s efforts to put both the air and political hostility into abeyance, Keeling’s measurements of the air’s gaseous composition ushered in a new cosmopolitics. It was a cosmopolitics which changed our relationship with the sky. No longer the domain of the gods or the vicissitudes of an indifferent Nature, the sky was rendered social. In drawing associations between human actions the global atmosphere, Keeling and his contemporaries and followers did ‘politics’, “in the sense of altering the associations – and thus directly the ‘social’ – that all beings establish with all other beings.” (Latour, 2012: 72). This new cosmopolitical space has been called experimental – not in the epistemological sense of control and repetition, but in the more unnerving sense of inadvertent drivers and indeterminate outcomes. While participation in Boyle’s experimental community was tightly regulated and symptomatic of a deeply stratified polity, this new planetary experiment renders us all both object and subject; both knower and known.

The site of this new cosmopolitics – its principle ‘centre of calculation’ – is the Mauna Loa observatory in Hawaii. Strategically located above the layer of particulate industrial pollution, the observatory reaches into the ‘well-mixed’ portion of the troposphere, where representative samples of the global can be captured, sealed and processed. This site thus speaks for the globe, and its geography renders it the perfect fulcrum from which to narrate the shifting cosmology of the sky: from ethereal purity to experimental hybridity.

Most of the words we use to describe this experimental situation trade upon a lack of something, rendered by a negative prefix: think of ‘indeterminacy’ or ‘uncertainty’. Perhaps that is why numbers like 400ppm or 2°C have such potency. They offer a temporal and phenomenological anchor amid the ongoing unfolding of our collective futures; a restoration of epistemic and political order like that promised by the air pump. Just as Robert Boyle offered a new epistemology for his turbulent times, climate science has offered numbers that become the currency of political deliberation.

While the readings of 400ppm are unnerving, these observational figures provide a peculiar comfort amid the epistemological ambiguity of climate change. Unlike model projections of future changes and measurements of the atmosphere’s thermal energy, CO2 numbers have not been subject to public tussles over their scientific veracity. There is something reassuringly empirical and controlled about sealing a flask, taking it to a laboratory, and teasing-out the tiny molecules of CO2. The subsequent visual inscriptions, particularly the iconic ‘Keeling Curve’, have been powerful allies to those who read from these upward-trends a compelling argument for social and political change.

While numbers like 400ppm are useful pointers and descriptors, they unfortunately help us little with the task of responding to climate change equitably, democratically, and justly. We should see Keeling’s flasks, with their hermetic fastenings, not as a metaphor for rational control but as an instrument of atmospheric cosmopolitics. They should remind us that the climate is a space of emergent associations; of a political complexity that we are only starting to ascertain in our own cosmologies; to capture in our own flasks. 


Connor S 2010 The Matter of Air: Science and Art of the Ethereal. London: Reaktion Books.
Ezrahi Y 1990 The Descent of Icarus. Cambridge, MA: Harvard University Press.
Latour B 2012 Reflexive modernity brings us back to Earth. In: M. Heinlein et al. (eds) Futures of Modernity: Challenges for Cosmopolitical Thought and Practice. Bielefeld: Transcript Verlag, pp. 65–75.
Shapin S and S Schaffer 1985 Leviathan and the Air-pump: Hobbes, Boyle, and the Experimental Life.Princeton, NJ: Princeton University Press.