The human brain is arguably the most complicated machine on Earth. It's capable of amazing feats of creativity, immersion and insight. There's no single factor that drives our attitudes and beliefs about climate change. The human brain is not that simple. Nevertheless, our brain hasn't evolved much in tens of thousands of years. Where much the same is our early ancestors struggling to survive in Africa 50,000 or more years ago, our chief concerns were immediate dangers that affected our own small group. However, climate change is unlike any threat humanity has ever encountered. It involves gradual changes across the whole planet over decades rather than immediate danger from predators. People think of climate change as affecting other people in far away parts of the world, or not affecting people at all. Thinking about what might happen to some other group in a distant part of the world, decades into the future just doesn't come naturally to us. Of course, the reality is climate change is affecting all parts of the world right now, but that's not how most people think about the issue. It turns out there are a number of psychological barriers preventing people from acting to prevent climate change. Robert Gifford at the University of Victoria calls these dragons of inaction. Let's have a look at some of these dragons. Firstly, when events seem far away, people tend to discount them. One study of 18 countries found that people thought that environmental conditions were worse in other countries. Of course, people in those other countries also thought the same thing about different countries. When it comes to climate risks, the grass is always greener on our side. Secondly, people tend to be overly optimistic about climate change. One study found that people systematically underestimate the risk they face from environmental hazards. Nah, climate change won't happen to me. Is a prevailing attitude. So people tend to be overly optimistic about climate risks. On the other hand, a third dragon of inaction is pessimism about our own ability to make a difference to climate change. Avoiding the worst impacts of global warming requires big changes to how our society produces energy. In the face of such a global, complicated problem, many people believe they personally can't make a difference. This feeling of helplessness prevents people from making changes to their behaviour that will help avoid climate change. Fourthly, the behaviour of people around you is an extremely powerful motivating force, more powerful than most people realise. If you look around and see that your friends and family aren't doing their part, then you're more likely to not bother either. Why should I change if they won't? A third dragon of inaction is when people do act for the environment. For instance, change their light bulbs or recycle. But then they think, well, I've done my bit. Unfortunately, these token actions are often relatively easy, but don't have much impact compared to the more difficult long-term behaviour changes. Finally, a growing body of evidence has identified our sixth dragon of inaction, which is particularly significant and damaging. In fact, it's two dragons combined. We'll come back to that in a moment. In recent years, a number of studies have identified that perception of scientific agreement is a key gateway belief. When people realise this strong agreement among climate scientists that humans are causing global warming, this influences a range of other climate beliefs, including acceptance of climate change and support for climate action. Instead of you asking the public to estimate how many climate scientists agree about human cause global warming, they say around 50 to 60%. The public still think there's a 50-50 debate among climate scientists. In contrast, 97% of climate scientists agree that humans are causing global warming. So there's a gaping chasm between public perception and the 97% reality. This is a consensus gap. As perceived consensus has such a big influence on other climate attitudes, the consensus gap is an important dragon of inaction. But I mentioned this was the result of two dragons of inaction. What are they? Let's have a look at some experimental data I've collected, which gives the answer. This graph shows the result of a survey I ran with a representative sample of Americans. I asked participants to estimate how many climate scientists do you think agree that humans are causing global warming. I also asked about their support for free unregulated markets, which is a measure of political ideology. This graph shows the perception of consensus decreases as you move to the right, which equates to more conservative people with higher support for free markets. In other words, political ideology plays a big part in increasing the consensus gap. This result has been found in many studies, which find that political beliefs are one of the biggest influences on our attitudes to climate change. But even for people at the other end of the political spectrum with very low support for free markets, there was still a large gap between perceived consensus and the 97% reality. I call this the liberal consensus gap. There's no political motivation for a liberal to think that there's a low consensus among climate change scientists. The two possible contributors to the liberal consensus gap are ignorance, in other words, a deficit of information, or confusion arising from misinformation. There are many psychological barriers that prevent concern about climate change, some based on confusion and misconceptions. That is something that we can do something about.