We all agree about communicating climate consensus, dont we?
Five hundred US-based earth scientists have published a statement that “science unequivocally demonstrates” humans are affecting the environment through climate change. But although statements of consensus have become commonplace over the past decade, surveys indicate people still believe scientists disagree. So is it really possible to create effective messages about consensus?
What is scientific consensus?
Scientific consensus is a measure of where the weight of evidence lies in a particular discipline. In the case of climate change, the weight of evidence indicates that human-produced greenhouse gases are trapping heat in the atmosphere, causing it to warm – and it’s a position the vast majority of scientists subscribe to.
Over the past decade, scholars have attempted to measure how strong this consensus in the climate science community is. Most recently, the climate science blog, Skeptical Science, produced a study indicating that of 12,000 papers on climate change 97 per cent of those that expressed a view on the causes of climate change said it was mostly down to human activity – a very similar result to that of previous studies.
The value of consensus
According to John Cook, lead author of the Skeptical Science paper, the motivation behind the new paper is that studies suggest people are more likely to accept human-caused climate change – and action to tackle it – once the broad agreement between scientists is highlighted.
But even though studies have consistently found the vast majority of scientists agree on the causes of climate change the public still appears to believe there is significant disagreement. In 2011, only 39 per cent of US citizens polled said they thought there was consensus over climate change.
Why the mismatch in perception? Scholars point to allegations that there have been deliberate efforts – including within the US government – to suggest scientists disagree about the causes of climate change. According to other studies, there is a ‘false balance‘ in the media, where skeptic views have been given equal weight to mainstream climate science. But how successful are scholars and scientists’ attempts to push back?
Knowledge deficit or cultural bias
The Skeptical Science paper drew criticism from Yale University’s Dan Kahan, whose own work suggests people’s worldviews or cultural bias – for example whether they accept or reject intervention in markets to tackle climate change – are likely to colour whether or not they accept climate science. Release as many statements of consensus as you like, Kahan contests, you’re just preaching to the choir.
Kahan says such studies fall under the “knowledge deficit” model of communicating climate change, which assumes people reject mainstream climate science because they are not sufficiently educated. His work indicates cultural norms and people’s worldviews might be more influential in whether or not they accept humans are causing climate change.
Kahan also points to work led by Dr Adam Corner, which suggests that repeatedly issuing statements of consensus may reinforce polarisation – not necessarily a good outcome for public engagement with climate science.
In response, Cook counters that the ‘consensus gap’ is a “product of lack of informationand cultural bias” – so a bit of knowledge deficit communication is still necessary. Says Cook:
“[T]he key feature for the purpose of this discussion is that even for liberals, there is still a large gap between perceived consensus and the 97 per cent reality. This indicates that there is still a significant lack of awareness of consensus, even among those whose cultural values are predisposed to agree with [human-caused climate change].”
Dr Alice Bell, an academic in science communication and policy based at the University of Sussex, says statements of consensus are an understandable retort to claims that there is disagreement between scientists, but calls them a “blunt” way to measure science. She says:
“Scientific papers are complex pieces of work in themselves, so if this were the only way scientists communicated with the public, much of the richness of the debate would be lost.”
Bell argues that consensus statements may have their place – indeed, as consensus is an appeal to authority, some people may like them. But, she argues:
“There should be more specific and personal interventions from climate scientists, too -discursive events where scientists and members of the public can interact with one another as individuals.”
Unsettled science
Other commentators have highlighted the need for nuanced communication. A Nature editorial this week highlights the pitfalls of over-simplistic messaging in climate science:
“The problem with simple messages and black-and-white statements is that they tend to be absolutes and so the easiest to falsify.”
Currently, scientists are enthusiastically discussing precisely how much warming we can expect for a doubling of carbon dioxide in the atmosphere, known as climate sensitivity. If hammering home scientists’ consensus position on human-caused climate change has the effect of implying all the science is settled, it’s easy to confuse such discussion points with casting doubt on the fundamentals.
As Nature puts it:
“Even legitimate debates on outstanding issues – climate sensitivity, say – can now be painted as unsettling not just to the scientific position, but also to the policy response it demands.”
In other words, broad agreement on certain fundamentals of climate science can coexist with elements of disagreement in other areas. In that sense, communicating the scientific method is just as important as the science itself. Luckily, that’s something most climate communicators seem to agree on.