Mrs Benn

It’s always flattering to be pictured alongside somebody older than oneself. A kind lady took this photo for me in Chicago’s wonderful Field Museum. There, I was thrilled to see a fabulous collection of dinosaur fossils. The Museum estimates that at least 90% of the bones on display are genuine fossils. A small fraction are reconstructions, because of course no dig, however, careful, can recover an entire fossilised dinosaur undamaged.

The Museum’s exhibits addressed head-on the reasons for the great cycles of extinction that the Earth has witnessed during its 4 billion years in existence. Above all else, climate change has been a driving force for mass extinction. The Earth is now on an irrevocable course for climate change on a scale that has only previously been witnessed during mass extinction events. Indeed, mass extinction is already underway on Earth; species are being lost at a colossal rate. The Museum presented evidence fearlessly and without pulling its punches. The candour of the exhibits was impressive, given that President Trump dismissed climate change as a Chinese hoax, and mounted a campaign of repression against government-funded scientists who published data on climate change. It was alleged that work on climate change was political, but it was in the publication of hard data that so many US research groups and agencies, for example NASA, have made such important contributions to scientific understanding of the catastrophic consequences of fossil fuel use and the destruction of ecosystems.

I first taught a course that touched on climate change nearly 30 years ago. I began reading the burgeoning literature with horror. There was already, in 1995, a vast amount of evidence for correlations between global temperature changes and atmospheric carbon dioxide concentrations. The famous “hockey-stick” graph published by Michael Mann in the late 90s, predicting rising global temperatures over the next decade, has been tested and corroborated; Mann’s predictions have been found to be – sadly – all too accurate and worse, the trend of global warming appears well set. In the media, and in the minds of lobbyists for petroleum companies, perhaps it is acceptable to speak of debate about the science. However, for scientists, who understand the scientific method, and the uncompromising role of data in falsifying defective hypotheses, there is no significant doubt about the substance of the theory of global warming, just uncertainty about how to respond and sadness about the inaction of governments.

I am not a climate scientist, but I have followed the literature for the last three decades. Sometimes I find it too depressing to read, because I fear the future that my children will inherit. Recently scientists have begun to ask whether they have in fact been too cautious about sounding the alarm bell. For many years, climate scientists feared being accused of alarmism if they looked at “worst-case” scenarios. They preferred to talk about aiming to limit global temperature changes to 1^oC, then 1.5^oC. It now appears that it will be difficult to limit warming to 2^oC, and some scientists are warning that in their anxiety to avoid the accusation of fear-mongering, climate scientists have failed adequately to inform the public of the extreme consequences of climate change that we are racing towards. The fear is that the Earth will simultaneously reach a number of tipping points, that will push it into a vicious circle of warming events from which it will not easily recover. For example, the Siberian permafrost is thawing; it contains billions of tons of methane, 100x more potent an absorber of heat than CO2. If this methane is all released into the atmosphere, as is already starting to happen, the impact on global temperatures will be colossal.

What is so desperately sad is that the notion of a greenhouse effect is not new. Ursula Le Guin talks about it in her 1971 novel The Lathe of Heaven, by which time this scientific idea was already spreading in popular culture. The intervening five decades have been marked only by a relentless accumulation of data and a continuing and terrifying corroboration of the core models and hypotheses. We knew this catastrophe was coming, and it was entirely preventable.

In that context, President Biden’s announcement of a massive Federal programme of expenditure designed to transform the infrastructure for generation of energy in the US is very timely. The US is the world’s greatest emitter of CO₂; without sweeping change in energy use in the US, the world may not be able to tackle the challenge of climate change. Moreover, US leadership in energy will make it increasingly hard for environmental criminals like Jair Bolsonaro to continue their vandalism unchecked. Biden’s announcement has come not a moment too soon; there may be time to haul ourselves back from the abyss, but make no mistake, the clock is ticking. There is not much time left to save ourselves.