First, I will acknowledge my own bias. I believe that human activity is changing the earth’s climate at a dangerous rate. I believe that the scientific evidence on this point is overwhelming, that we have already seen clear and comprehensive proof of the thesis, and that it is very possible that we have already reached a point where some damage may be irreversible. This is the near-universal consensus of people who have spent their lives studying this issue, and, while I have not spent my life studying it, I stand with those who have.

But this is not what I want to write about today. I don’t want to rehash the arguments for or against climate change; rather, I want to talk about the way that we process arguments about things like climate change (whether or not it is actually happening). It is, I will suggest, a rigged debate. The human mind is structured in such a way that it would require terrifically more evidence to convince us that we are endangered by climate change than to assure us that we are not. Here are some reasons why:

 

1. Our “danger” triggers are almost entirely short term. This is largely how evolution works.

We are extremely good at assessing and avoiding immediate threats — tigers in the brush, strange people following us home, a car going the wrong way in our lane. When things like this happen, our fight-or-flight mechanisms kick in immediately, and we often overreact to the threat.

But long term threats don’t affect us the same way. That’s why most of us don’t save for retirement or even exercise very much. And it’s why three or four really cold days in a row are enough to convince half the population that there is no such thing as global warming.

And even those rare humans who can appreciate dangers years in the future fall short when it comes to dangers centuries in the future. When we hear, say that average temperatures are rising a half a degree a century, or that there is a danger that “a major section of west Antarctica's ice sheet will completely melt in coming centuries,” we just can’t get too worked up about it. Our brains were not designed to think in centuries.

The earth, however, operates on a very different scale. Evolution is a long process. When climate skeptics say things like, “the climate is always changing,” they are absolutely correct. The climate is always changing on the Earth’s time scale, over tens of thousands and millions of years. And when it changes this way, species have a chance to adapt to the changes. The entire ecological balance moves with the changes in climate.

But two or three hundred years — an unimaginably long time in any human mind — is far too little time for ecologies to adapt to changes. The difference between the human and the geological perspectives on time, in this case, is the difference between a transition and a catastrophe.

 

2. We prefer to believe what we prefer to be true. This is called the confirmation bias, and it is very real.

It evolved to help us defend positions that we have already arrived at for other reasons (mainly our own interest). And this means that it takes an unimaginably large amount of evidence to convince us to change our minds, and practically no evidence at all to convince us that we were right all along.

In discussions of climate change, the confirmation bias makes all the difference. Pretty much nobody wants global climate change to be real, or to be something that human beings can control, because that means changing the way we do stuff — traveling less, investing in other kinds of energy, radically changing our consumerist lifestyles, and that kind of thing. Who wants to do that?

The strong interest that we have in climate change not being real allows many of us to create a complete equivalence between, on the one hand, an overwhelming scientific consensus and, on the other hand, a few outliers and an occasional debate around the margin. This is why the debate is rigged.

 

3. We are very bad at holding resources in common. This is what ecologist Garrett Hardin called the “tragedy of the commons.”

When a resource is held in common, it is in everybody’s collective interest to conserve it. However, it often works out that it is in everybody’s specific interest to exploit it because, if they don’t, somebody else will, and then they will end up losing twice.

The global climate is the ultimate commons. Nobody owns it, everybody needs it, and one person's (or even one country’s) attempts to protect it can easily be cancelled out by people on the other side of the world exploiting it more. Once we are in a tragedy of the commons situation, then our basically self-interested evolutionary logic tells us that we better get what we can since there is really nothing we can do to stop whatever is coming. And this is why it is a tragedy. All tragedies end badly.

These profound and persistent biases make it very difficult to address problems like global climate change. But they do not make it impossible. We are not slaves to our wiring. We can overcome cognitive biases. But first we have to recognize them and acknowledge the influence that they have on our capacity to make decisions. I believe that the human community will one day be able to do this, and, when we do, address the issue of climate preservation as a global community. I sincerely hope it will not be too late.