Josie Appleton, in the course of reviewing Mark Lynas’ new book Six Degrees: Our Future on a Hotter Planet identifies the influence of the Zeitgeist’s changing paradigms in the social construction of (supposedly) scientific theory.

If you look at the dates on the citations in Six Degrees that deal with carbon feedback cycles, global emissions scenarios or the impact of temperature rises on agriculture and ecosystems, then you’ll see that the majority of them date from 2004-2006. It was only very recently that scientists started running the models on which Six Degrees is based, predicting the collapse of ecosystems and wild feedback loops that would take us from two degrees to apocalypse. Why was this? If we trace the development of scientific theories about global climate, we can see how they shift in predictable relation to the preoccupations of the time – which suggests that a similar thing could be occurring now.

The assumption for much of the twentieth century was that the climate system was stable, and that it would adjust to absorb imbalances. One past director general of the UK meteorology office stated: ‘The atmosphere is a robust system with a built-in capacity to counteract any perturbation.’ Where opinion differed from this, it did so in highly predictable ways, in direct relationship not to the shiftings of the planet but to the shiftings of the political zeitgeist.

We find that in the wake of the Cuban Missile Crisis of 1962, as the world seemed to be poised on a knife’s edge and total destruction a possibility, a number of climate scientists – at the same time and independently of each other – discovered instabilities in the climate system. In 1964, one ice expert discovered instability in the Antarctic, which he said ‘provides the “flip-flop” mechanism to drive the Earth into and out of an ice age.’ Others came to the same conclusion, and the ‘flip-flop mechanism’ was the subject of scientific meetings and conferences.

In the 1970s, in the context of the global slowdown and the end of the easy years of the postwar boom, climate scientists started to predict that the climate would become harsher in future. One oceanographer predicted that the ‘amiable climate’ we had been used to would give way to a new ice age. A Time magazine article summed up that scientists disagreed over whether there would be ‘runaway glaciation’ or ‘runaway deglaciation’, but what was certain was that ‘the world’s prolonged streak of exceptionally good climate has probably come to an end – meaning that mankind will find it harder to grow food.’ So a society in the grip of the energy crisis finds that in the future it will be ‘harder to grow food’.

We can also see political concerns imprinted on scientists’ theories of the Earth’s past. In the 1980s, scientists formulated the theory that the dinosaurs had been wiped out by the striking of a giant asteroid. One scientist at the time noted that such theories should be measured not just by the facts of nature, but also against the concerns of the age. ‘[The asteroid theory] commanded belief because it fit with what we are prepared to believe.… Like everyone else…I carry within my consciousness the images of mushroom clouds…. [It] feels right because it fits so neatly into the nightmares that project our own demise.’

Fast forward to the early twenty-first century, when scientists decided that the climate system was fragile and subject to dramatic and irreversible shifts. In 2001, one academy declared: ‘Geoscientists are just beginning to accept and adapt to the new paradigm of highly variable climate systems.’ The phrase everybody started to use was ‘tipping point’, meaning the point where the Earth’s system would reach its ‘limit’ and tip over into an irreversible change. (This was particularly the case after the 2004 Hollywood hit, The Day After Tomorrow, which envisaged the onset of a global freeze in a matter of hours.) The question many scientists started asking of nature was ‘what is its tipping point?’. At what point would the Arctic and Antarctic go into irreversible meltdown? At what point would the carbon cycle go into reverse? At what point would this or that ecosystem collapse? When would extreme weather events start to increase?

Scientists started to carry out impact studies, and they started to look at feedback cycles. These are loaded concepts: impact – showing the damaging effect of temperature rise on ecosystems – and feedback – the inbuilt instabilities that could lead to ‘runaway’ change. Nature was viewed as fragile, interconnected, and liable to spin away dramatically beyond our control. In 2005, one Russian scientist predicted an ‘ecological landslide that is probably irreversible and is undoubtedly connected to climactic warming.’ It is these studies, then, that form the references at the back of Lynas’ book, and which provide the basis for his claims of the meltdown that will occur at two degrees.

You don’t have to be Thomas Kuhn to read the (mixed) metaphors here. We’re hitting the ‘ecological buffers’, says Lynas, ‘fiddling with the earth’s thermostat’. Once feedback starts, ‘the accelerator will be jammed, and there will be nothing we can do to cut the speed of climate change’. ‘[N]o one can say for sure where this tipping point might lie, but it stands to reason that the harder we push the climate, the closer we are likely to get to the edge of this particular cliff.’ Just as in the 1980s asteroid theories felt ‘right’ because of the images scientists carried in their consciousnesses, so now, too, the political climate colours models of nature. We can see how social anxieties – a fear of change, a sense of the fragility of things – guide the questions that scientists ask, and the kinds of theories that ring true.

That doesn’t mean, of course, that these theories are incorrect. Every theory of nature to some extent draws its metaphors from the society of the time. In Darwin’s theories of natural selection we see something of the individualistic market society of the nineteenth century, with individual organisms fighting it out and the ‘fittest’ surviving. In the early twentieth century, when political opinion shifted away from competition and towards social reform, biologists started to focus on the cooperative relationships between organisms, founding the science of ecology and posing theories of selection ‘for the good of the species’. Science must draw its models from society, because after all scientists are human beings not machines; science is a model of nature reconstructed in our heads. This is not a source of inaccuracy, but the essence of intellectual enterprise: nature cannot be accessed ‘in the raw’ but always must be described with words and reconstituted in thought.

As a rule of thumb, the more self-critical the science, and the more it tests itself against reality, the more accurate it will be. If all theories draw their metaphors from society, some do so justifiably – in a way that grasps nature’s real operation – and some do in a way that merely distorts and mystifies. So, as it happens, Darwin was right and the ‘good of the species’ theorists were wrong: their theory was based merely on wishful thinking, on how they wanted nature to behave rather than how it really did. The thing that separated Darwin from others was his systematic testing: he spent years closely scrutinising species, measuring his ideas against the evidence before his eyes. Even in his Origin of Species he raised all the facts that did not fit into his theory, and sought to adapt his ideas in order to explain them.

The less self-reflective the science, and the more it is founded on political and moral campaigns, the less reliable it is likely to be. And in Lynas, we see how global warming science has become a foil for a whole series of political and moral agendas, a way of discussing everything from the sins of consumerism to human arrogance. Outlining the effects of a four degrees rise in temperature, Lynas writes: ‘Poseidon [God of the sea] is angered by arrogant affronts from mere mortals like us. We have woken him from a thousand-year slumber, and this time his wrath will know no bounds.’ Not only Poseidon and Gaia but also terms such as ‘Mother Nature’ and ‘nature’s revenge’ have slipped into everyday discussion about climate change. Darwin did not, so far as we know, give names of Gods to his finches. When scientific concepts start to be discussed in such emotional terms, it suggests that they say more about wish than reality.

The scope for climatology to slip into fantasy is heightened by the fact that it is a relatively open and uncertain field. Time and again in the twentieth century, climate scientists noted how shaky their art was. It was a case of one man, one model, and everybody thought that theirs was the right one. Today’s models include many interacting factors that are incompletely understood, and different models can produce drastically different results. Lynas quotes a couple of studies that found that global warming will lead to increased rainfall in the Sahel, meaning higher crop yields, but another study that found severe drought. (Needless to say, he favours the drought scenario.)

Read the whole review.

Hat tip to Karen L. Myers.