There is a variable that can massively influence how bad global warming might get : us. It’s time to take the human factor seriously.
Originally published in New Scientist
Climate scientists are in no doubt that global warming is almost entirely the result of human activity. Which makes it odd that attempts to predict how things will pan out have paid lip service to human behaviour, one of the key factors determining whether a sustainable future is possible.
While a vast array of influences are routinely included in computer models that simulate possible future climates, from cloud coverage to land use, a realistic account of how people perceive and respond to climate risks and alter habits or carry on as usual has been largely absent.
Typically, this ‘human dimension’ has been limited to population-level inputs that assume we are economically rational decision-makers, behaving in a way that optimises financial gains and minimises losses. This conception of human behaviour is now thoroughly debunked.
A new study suggests a better way of including the human factor, presenting a model which couples a well-established psychological theory of behaviour change with more familiar climate metrics (Nature Climate Change).
The authors show that how we view extreme weather events, combined with attitudes towards climate risk and the influence of social norms and a sense of whether your own actions make a difference, all direct personal decisions that, collectively, create very different outcomes in terms of global temperature rises.
Including the human factor in the model in this more sophisticated way turns out to have a big quantitative effect: the resulting reduction in energy use in the best case behavioural scenario lowered the global temperature by the year 2100 by as much as 1.5 °C compared to the same model without this factor. That’s a great example of people power and could be enough to avert truly disastrous climate change.
In one sense, what the paper shows is not surprising, and simply formalises in a computer model something that social scientists have been demonstrating for years – that the attitudes, behaviours and social preferences of ordinary people have a considerable influence on how the climate is changing, through energy use, meat consumption, travel, and much more besides.
While international political agreements and technological innovations to cut emissions tend to get the most attention, billions of individual decisions taken across the world add up to a significant driver of climate change.
Not so long ago, this statement would hardly have been worth making – tips showing how individuals could cut their carbon footprint were all the rage. But as it became clear that changing behaviour was much harder than many campaigners initially assumed, the focus moved on to ‘macro’ approaches such as decarbonising the energy sector and the development of electric vehicles.
In yet another shift, there seems to be renewed interest from the UK government in changing behaviours. Following the dramatic reduction in single-use plastic bags after the introduction of a small charge, disposable coffee cups are next in line. These nudges towards less-wasteful daily behaviours are welcome, but the big question remains: how to leverage these small tweaks into more substantial behavioural changes, such as eating less meat.
Here, the evidence is not encouraging. A study of the plastic bag charge in England found that although attitudes towards other waste-reducing actions became slightly more positive, there was no real ‘spillover’ to other types of sustainable behaviour.
Part of the problem is that admirable initiatives like the bag charge are generally not presented as the ‘beginning’ of a sequence of changes required to really make a difference. Unless you clearly link the need to waste less plastic with the need to travel less and eat more sustainably, most people simply don’t join the dots.
That’s also a key message to take from this new study on the human dimension of climate change. There is no inevitable relationship between experiencing extreme weather, feeling worried about climate change, and using less energy, supporting green policies and the alteration of our climate trajectory. If people don’t believe their actions make a difference (perceived behaviour control) and don’t see others around them taking an interest too (social norms) then they probably won’t change.
Communication is key to altering behaviour. Getting the public to see that this not just about supporting charges for coffee cups, but going on to make changes to travel, heating and eating habits, will be crucial. Because ultimately, the single biggest uncertainty in how bad climate change will be is ‘us’.
Photo credit: Dylan Passmore