Climate science has struggled mightily with a messaging problem.
The well-worn tactic of hitting people over the head with scary climate change facts has proved inadequate at changing behaviour or policies in ways big enough to alter the course of global warming.
While Europe has made some headway, the largest obstacles to change remain in the United States, which has historically been responsible for more emissions than any other country. And perhaps most important, climate change denial has secured a perch in the Trump administration and across the Republican Party.
Enter the fast-growing academic field of climate change communication. Across a swath of mostly Western nations, social scientists in fields like psychology, political science, sociology and communications studies have produced an expansive volume of peer-reviewed papers — more than 1,000 annually since 2014 — in an effort to cultivate more effective methods for getting the global warming message across and inspiring action.
While recent polls have shown an increase in the percentage of people who describe themselves as worried about climate change, experts say not enough people have been motivated to act.
"The main reason people reject the science of climate change is because they reject what they perceive to be the solutions: total government control, loss of personal liberties, destruction of the economy," said Katharine Hayhoe, director of the Climate Science Center at Texas Tech University.
"But ironically, what motivates people to care and to act is an awareness of the genuine solutions: a new clean-energy future, improving our standard of living, and building local jobs and the local economy."
Social-science investigators have found that the most effective tools for engaging the public in the subject of climate change are those that appeal to core human tendencies. For example, people tend to focus on personal and local problems happening now, which means talk of the last remaining polar bears stranded on shrinking icebergs, far from most people, is out.
The best climate-related appeals are not a collection of statistics, but those that target people's affinity for compelling stories. They also work best if they avoid fear-based messaging (which can cause a head-in-the-sand effect) and provide a sense that individuals can affect the environment in a personal and positive way — by updating to energy-efficient appliances, for example, or eating less meat, given meat production's heavy carbon footprint.
But these efforts at persuasion are up against a well-financed opposition.
In the United States from 2000 to 2016, major carbon-emitting industries spent more than US$1.35 billion lobbying members of Congress on climate change legislation. They outspent environmental groups and renewable energy companies 10 to 1, according to a paper last year in the journal Climate Change by Robert J. Brulle, an environmental sociologist at Drexel University in Philadelphia.
A 2015 paper by Bruce Tranter, a sociologist at the University of Tasmania, analysed 14 Western nations and identified an association between a country's per capita carbon footprint and the prevalence of climate science scepticism among its citizens.
And in a recent study published in Nature Climate Change, Matthew J. Hornsey, a social psychologist at the University of Queensland, found that nations that had the strongest relationship between political conservatism and climate science scepticism tended to be those with economies more highly dependent on the fossil fuel industry, including the United States, Australia, Canada and Brazil.
At the vanguard of the social-science-based response to such doubt is a pair of centers for climate change communications research at George Mason University and Yale University.
These research hubs just released new polling data indicating that 96 per cent of liberal Democrats and 32 per cent of conservative Republicans support the Green New Deal — a public-opinion gap that widened by 28 percentage points between December and April as awareness about the proposed legislation grew.
In 2009, the two climate labs produced the highly regarded "Six Americas" report, which identified six different groups of Americans who represented the range of public opinion on climate change.
On one end of the spectrum are the "alarmed," who are the most certain, and most concerned, about human-driven global warming. They're also the most motivated to act to protect the climate. On the other end of the spectrum are the "dismissives," who, as their name suggests, are least likely to accept or care about climate change. Between the two polarities are "concerned," "cautious," "disengaged" and "doubtful."
The report has been updated repeatedly since its release and is often used by climate communication researchers to tailor their efforts to each demographic.
One such operation is the nonprofit Climate Outreach, based in Oxford, England. It recently issued a handbook that uses social science research to help climate scientists become better public champions of their own work.
Climate Outreach has also tapped into research that has identified especially effective visual techniques for communicating about climate change.
For example, authentic photos of people actively engaged in global-warming mitigation — such as community members installing solar panels on a roof — are far more resonant than, say, images of politicians at the lectern of a climate conference. So Climate Outreach started Climate Visuals, an open library of research-tested, impactful images.
Major environmental organisations such as Greenpeace and the Sierra Club are also looking to social science to inform how they communicate about climate change, including their choice of imagery, as are federal agencies such as the National Aeronautics and Space Administration (Nasa) and the National Oceanic and Atmospheric Administration (NOAA), according to the agencies' representatives.
Edward W. Maibach, director of George Mason University's Center for Climate Change Communication has recruited an ever-expanding army to speak about climate science to the masses. His research revealed that the public puts particularly high trust in local TV weathercasters and health care providers as sources about climate science. So over the past decade, Maibach's team enlisted 625 on-air meteorologists to give newscasts that help viewers connect the dots between climate change and hometown weather.
Another member of the George Mason team, John Cook, is one of various global academics working with a teaching method known as "inoculation," which is a preventive strategy grounded in the finding that it can be very difficult to extract misinformation once it has lodged in the brain.
Cook has designed a high school curriculum as well as a popular online course that presents students first with facts and then a myth about climate change; the students are then asked to resolve the conflict.
In Europe, Sander van der Linden, a social psychologist at the University of Cambridge, codesigned an inoculation-based online game with doctoral researcher Jon Roozenbeek.
The game was designed to help its hundreds of thousands of players become better consumers of climate-related information.
"We're trying," van der Linden said, "to help people help themselves and navigate this post-truth environment."