For fans of probability, confidence intervals and margins of error, climate change is a dream come true. For everyone else, the fact that uncertainty (inherent in any complex area of science) has gradually become one of climate change’s defining features is a constant headache. Because uncertainty – real or manufactured – is a well-rehearsed reason for inaction.
What proportion of scientists agree that human activity is changing the climate? How sensitive is the climate to carbon emissions? Is it very likely or merely likely that flooding will increase? And what does likely mean anyway?
Questions such as these have become a stick with which to beat climate models. Scientists (naturally reticent in their communicative style) feel obliged to reel off lists of things they don’t know, and forget to re-emphasise the (remarkably certain) link between human behaviour and climate change.
The precautionary principle (slippery concept that it is), rests on the idea that less-than-complete knowledge is no reason for inaction. But spreading doubt, playing down the scientific consensus, and focusing obsessively on uncertainties has been the central strategy of climate sceptics, following the helpful example of the tobacco industry before them.
Clearly, there is much that could be done to improve the communication of uncertainty. Scientists could focus on the knowns before the unknowns. Communicators could re-frame the issue as one of risk, a concept familiar from the insurance industry, rather than uncertainty. Verbal statements of uncertainty could be accompanied by numerical figures, to overcome individual and cultural biases in their interpretation.
But there is also only so much that refining our communication of uncertainty will achieve. Because while we obsess over solar flares and natural cycles, we overlook the single biggest uncertainty in the climate system: us.
Fundamentally, the amount of carbon dioxide that we emit over the next 50 years will determine the extent to which the climate changes. Unlikely as it is, the climate may yet reveal itself to be relatively insensitive to the billions of tonnes of greenhouse gases that we have pumped into it.
But even on the lowest credible estimates of climate sensitivity, burning half of our known reserves of fossil fuels will unleash unprecedented changes in the chemistry of our planet. So what we choose to do – and how quickly we can muster the collective willpower to do it – is an uncertainty that dwarfs all others.
The conclusion that it is us – rather than the climate – that is the most intractable source of uncertainty is the central theme in a new paper by Antony Patt and Elke Weber. They argue that our tendency to prioritise daily personal experiences over statistical learning, and our existing political views have a far greater influence on people’s views about climate change than than the error bars on scientists’ graphs.
Both the authors have spent a great deal of time analysing ways of improving the communication of uncertainty within climate science. So it is all the more intriguing that they write:
“Perceptions about the existence and extent of climate change may vary less as a result of how climate risks are communicated, and more as a result of whether solutions are portrayed as possible … (F)or people to support these policies in the first place, it is not sufficient and may not even be necessary for them to perceive climate change as a problem.”
In other words, uncertainty about the science is likely to dissipate in the face of meaningful engagement with effective climate solutions. When people feel inspired by the answers to climate change, they no longer see uncertainty about future predictions as the central question. But the longer the climate discourse is mired in the intricacies of uncertainty, the less likely it is that this kind of transformation will take place.
It is a difficult message for scientists to take on board – the careful communication of uncertainty is a central plank of their training. But the evidence continues to grow that the barriers preventing effective climate policies reside primarily with us (rather than the uncertain predictions of climate science). And the focus on finding the perfect method of communicating uncertainty may in fact be simply reinforcing the sceptics’ framing of the problem.
First published by Guardian Sustainable Business on 31.01.14