400ppm as Historical Event

When the Guardian reported last week that the famous ‘Keeling Curve‘ measure of atmospheric carbon dioxide, made at the Mauna Loa observatory, has hit an average 400ppm, it did so in terms which emphasized the moment as an historical event. A kind of step-change, or barrier passed. Of course, in scientific terms, 400ppm does not necessarily tell us very much. Climate modelling and prediction are heroically complex tasks, not reducible to crudely pickingĀ  a number from a series as a ‘turning point’. In part the choice to highlight this measurement now is part of the the continuing scientific struggle with the apologists of inaction, who have recently been seeking to selectively exploit recent temperature data to suggest global warming has stalled.

Yet, what is interesting to me as an historian is the representation of the ‘curve’ as historical, and in particular as evidence for a future historian looking back. This representation of the historicity of an attempt to measure and model our atmosphere and climate is both intriguing and important. It demonstrates the way in which the so-called ‘debate’ on climate change (something that would better be understood as a struggle) is deeply structured by our sense of time and history. In part it is perhaps an attempt to fill in for the fundamentally ahistorical, or perhaps, impossibly-historical, character of this field of science. One of the great problems for climate scientists, is that while they have developed powerful tools for understanding past and future climatic change, it is often difficult for these to talk to the human historical dimension. When told we are heading for disaster, we tend to ask “When will the disaster strike?”, or, “When is the point of no return?”. Such questions, which in some ways obfuscate the nature of the political issues at stake, stem from the historical turn of mind.

With this in mind, it is useful to look again at the curve, to consider the nature of the historicity it seeks to communicate. One is struck by the way in which the curve emerges from nowhere, the arbitrary starting date of 1958 is when Charles Keeling began recording the data. From that point, its repetitious peaks and troughs rise almost relentlessly. We can imagine it gently rising in the same manner well beyond 400ppm. As such this is a record of a natural catastrophe, a sign of some mechanism of transformation functioning beyond human control, the ever increasing energy demands and atmospheric pollution of industrial ‘progress’. It is the history of the ‘non-history’ of capitalism itself, ever on the rise, acting independently of human good or human will.

For this historian, however, what is evident is the absolute absence of historicity from the chart. There are no dramatic interventions into its data anywhere, no ‘events’ in the traditional historical sense, merely a continuous intractable rise. This lack of historicity, the absence of an ‘event’, is, however, what is most compelling and provocative about this graph. In the end, 400ppm is just another point on a line. It too will be surpassed in time and concentration like all the others. No human intervention has yet made any difference to the upward trajectory of the curve. Ultimately, the Keeling Curve tells us a story about the absence of a turning point, the absence of a political choice, and this is perhaps the source of our fascination with it. We study it in the hope of the appearance of an historical rupture; a point at which we choose to survive; the point at which capitalism is rendered no longer a natural force acting against our will, but subject to rational control.

We study this chart, then, for signs of revolution, and we are troubled by its absence. For we already know that only with the intervention of a political event will the Keeling Curve finally have been rendered truly historical.

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