How should we teach students about climate change?

A recent survey of US science teachers, published in Science, revealed a damaging misperception among teachers that has grave consequences for how students are being taught about climate change.

The survey found that only 30 percent of science teachers in US middle and high schools are aware that the scientific consensus on human-caused global warming is 80 percent or higher. This stands in stark contrast to the actual 97 percent consensus level among climate scientists, found in surveys, public statements, and peer-reviewed papers.

The gaping chasm between the perceived and actual level of scientific agreement on climate change, known as the “consensus gap,” has an unfortunate result: Many teachers present their students with both the mainstream consensus view that humans are causing global warming and the opposing minority view. This approach, known as “teach the controversy,” was initially promoted by groups opposed to teaching evolution in schools. While advocates of “teach the controversy” argue that it teaches students how to evaluate scientific evidence, the underlying intent was to cast doubt on the viability of evolution as a scientific theory.

The problem with “teach the controversy” when it comes to human-caused global warming or evolution is that there is no controversy—not a scientific one, at least. Teaching that scientists have major disagreements where they do not is simply to spread misinformation. How, then, should teachers approach climate change, when there is indeed social controversy surrounding it? The research suggests that acknowledging and explaining the controversy—a method sometimes called misconception-based instruction—is the optimal approach. Done correctly, this teaching method offers our best chance to reduce the spread of climate misinformation to our next generation of voters and policy makers.

When a controversy isn’t a controversy. For issues like climate change and evolution, it is important to distinguish between social controversy and scientific controversy. As a number of studies have shown, there is no controversy among climate scientists regarding human-caused global warming. Therefore, it’s a misrepresentation to “teach the controversy.” In fact, a number of psychological studies have found that in matters where there is scientific consensus, presenting both sides of the debate has a negative effect on science literacy. One experiment found that media coverage featuring accurate climate science from a mainstream scientist alongside misinformation from a contrarian scientist reduced acceptance of human-caused global warming and lowered support for climate-change mitigation policies. Similar results have been found for media coverage of environmental risks and the non-existent link between vaccines and autism.

When teachers present both sides of the “debate” on climate change, they are misinforming their students. Unfortunately, among US science teachers who gave instruction on climate change, 47 percent taught both sides. The consensus gap among science teachers is contributing to a consensus gap among their students.

But does that mean that science teachers should simply avoid airing the minority views of denialists? Should they replace “teach the controversy” with “ignore the controversy,” and stick exclusively to teaching mainstream science? Surprisingly, the educational research says no. Just sticking to the science is not the most effective approach to getting the facts across and reducing misconceptions.

This finding comes from research into misconception-based instruction, otherwise known as agnotology-based learning or refutational text. This method both teaches scientific concepts and explicitly mentions and refutes misconceptions. As science education professor Jonathon Osborne writes, “[c]omprehending why ideas are wrong matters as much as understanding why other ideas might be right.” Education is just as much about correcting misperceptions and promoting critical thinking as it is about downloading new information into student’s heads.

Two decades of research have found that misconception-based learning is one of the most effective means of reducing inaccurate understandings. Physics lessons that explicitly state and refute misconceptions produce significantly higher learning gains than lessons that simply explain the facts. A study of first-year psychology students found that lessons that introduced a misconception, then immediately countered it, were the most effective at removing it.

There are a number of other benefits to this teaching approach. Misconception-based teaching produces longer-lasting learning gains compared to traditional instruction: the lessons stick. It improves students’ argumentative skills, raising their awareness of the importance of scientific evidence. It equips students with critical thinking skills and holds their interest more.

So while educators should steer clear of the original “teach the controversy” approach, simply replacing it with “avoid the controversy” is sub-optimal. Rather, “explain the controversy”—meaning the social, not scientific, controversy—is the best approach. The teaching of science should be coupled with teaching how science gets distorted. This method inoculates students against misinformation, equipping them with the critical thinking skills they will need to make sense of misconceptions they may encounter in the future.

Getting it right. Addressing myths and misconceptions does carry some risks. If handled improperly, explaining the controversy can backfire and confuse rather than educate students. If teachers somehow suggest that there is not just social but also scientific controversy surrounding a topic of scientific consensus such as human-caused global warming, they risk misinforming their students. Addressing controversy offers the opportunity to teach critical thinking, but it is also important that students first have a solid grounding in the basic science. For example, a lesson debunking the myth that “human carbon dioxide emissions don’t matter because they’re small compared to natural emissions” would first need to explain the fundamentals of the carbon cycle. Only after students understand that natural carbon dioxide emissions roughly equal natural carbon dioxide absorptions can they conceptualise how much human-caused emissions have upset the natural balance.

Misconception-based instruction is already being applied in college classrooms. Daniel Bedford introduced it to his climate change class at Weber State University in Utah. After establishing basic climate science principles, Bedford instructs his students to analyse some climate misinformation literature (for example, Michael Crichton’s novel State of Fear). Similarly, Scott Mandia at Suffolk County Community College in New York provides his students with the scientific background to understand climate change before they refute specific climate myths in a final research paper. Some of his top-graded assignments, such as refutations of the myths that “the Medieval Warm Period was warmer than now” and that “ocean acidification isn’t serious,” were published online, to the delight of the students involved.

This teaching approach is also being applied by middle and high school teachers. An online survey of science teachers in Oklahoma found that many were re-purposing the “teach the controversy” approach, adapting it into a more productive “explain the controversy” teaching style. This enabled them to introduce climate science where it might not otherwise have been included, as well as promote independent decision-making and teach the students about the nature of science. By explaining the social controversy, teachers were able to neutralise it.

Misconception-based learning is a promising approach but teachers require resources and training to implement it. To address this need, I co-authored a textbook with Daniel Bedford that combines explanations of climate change concepts with refutations of common myths. It will be published in July 2016. In the meantime, other resources already exist. I was part of a team that developed an edX online course on climate science denial. It uses a misconception-based learning approach, refuting 50 of the most common climate myths while explaining the fundamental concepts of climate change. With the goal of furthering the adoption of misconception-based learning in high schools and universities, the creators made the videos and slides from this course freely available under a Creative Commons licence.

Climate science denial has been all too effective in lowering climate literacy levels and delaying public support for sorely needed mitigation to avoid the worst impacts of climate change. Misconception-based learning, applied to climate education, has the potential to reduce the influence of misinformation and remove a significant roadblock to action.