I came across a short TED talk by Martin Rees called Can we prevent the end of the World?. This lead me to another related talk by Martin Rees – which I’ve included below – called Is this our final century?. In case you don’t know, Martin Rees is the Astronomer Royal, a past president of the Royal Society, and he was the Master of Trinity College Cambridge.

I don’t actually know Martin Rees, but we did nod at each other in a toilet in Cambridge a few years ago, so I guess we’ve met (well, okay, that’s a bit of a stretch 🙂 ). I also attended a conference dinner in Trinity College at about the same time, and even though Martin Rees wasn’t involved in the meeting, he had apparently told the staff that they were not to complain about the fact that we were all unlikely to satisfy the dress code.

Although Martin Rees’s TED talks weren’t about climate change specifically, they were about some existential threats that we may face in the coming century. He seemed perfectly comfortable including greenhouse warming as being unprecedented and hence, I assume, a possible existential threat. He also argued that scientists should speak out, and that it was obvious that we should do what we can to minimise the risks associated with these existential threats. It all seemed obvious to me and yet it seems that this type of rhetoric is very difficult when it comes to climate change specifically.

Why? Well I think there are a vocal group of people who essentially apply a subtle (or not so subtle) form of blackmail. If you mention the possibility that the impact of climate change could be catastrophic, then you’re labelled an alarmist. Hence there’s a tendency to avoid this and, consequently, pointing out that surely we should do what we can to minimise the more extreme risks, can’t really be mentioned either. Also, we’re constantly told that scientists shouldn’t speak out, or else they’ll illustrate that they’re no longer being objective and therefore can’t be trusted.

I think this is all rather silly. It seems clear that there are potentially severe risks associated with climate change. It seems obvious that we should minimise the possibility of the more extreme scenarios. It also seems obvious that scientists should be free to speak out if their research indicates that we could face severe risks. What’s the point of paying scientists, and funding their research, if they aren’t free to speak out about the implications of what their research is suggesting?

I want to stress a couple of things, though. I’m not suggesting that climate change will be catastrophic, simply that the evidence suggests that this possibility exists. Ignoring this seems extremely short-sighted. Additionally, there may well be some existential threats that we wouldn’t choose to highlight – as there may be nothing we can do about them, and we may not know enough to have any real idea of how likely they are to occur in the next few centuries. This isn’t the case for climate change. We have complete control over climate change. It is us. Essentially, the only way that climate change could pose an existential threat is if we choose to do nothing about it. So, climate change isn’t by itself alarming. What’s alarming is the possibility that we’ll ignore the risks, do nothing, follow some kind of high emission pathway, and discover that climate sensitivity isn’t low.

Anyway, I really just found it interesting that a senior, high-profile scientist can give a TED talk about existential threats, how it’s obvious that we should avoid the high risk scenarios if possible, and also suggests that scientists should speak out, and noone seems to have made much of a fuss. Try doing this for climate change specifically and I think there’d be an outcry. Of course, even this post will probably produce cries of alarmist, alarmist because the title is Our last century? (ignoring the question mark and that it’s after one of Martin Rees’s talk titles) and because I’ve deigned to even mention the possibility of climate change being catastrophic. So, just to stress it again : I’m not suggesting that climate change is catastrophic, simply that there is a possible scenario under which it could be catastrophic. Furthermore, as William Connolley has pointed out before if you can’t imagine anything between “catastrophic” and “nothing to worry about” then you’re not thinking.