I had a discussion with someone recently who asked if climate change really was an existential threat for humans. I responded that it wasn’t. However, I added that this didn’t mean that it couldn’t be severely disruptive or that it meant that we couldn’t be creating an environment that we’d find very hostile, both in terms of the climate we could experience and the damage to the natural ecosystems on which we rely.
I find myself in a bit of quandary, because I think the extinction rebellion type narrative is too extreme, but I also find myself getting irritated by those who seem to suggest that we should simply rely on our current political/economic toolkits. I think that even if climate change is not a true existential threat, it’s still a very different type of threat to almost anything else we’ve faced before. I don’t really feel that our current political/economic environment is well suited to dealing with it, or – if it is – it clearly hasn’t demonstrated this yet.
A common narrative seems to be that we should be aiming for policy that is palatable; anything too ambitious either won’t be successful, or might do more harm than good. The problem I have is that we can often recover from poor policies. This isn’t the case for climate change, as I try to argue in this post. So, why do we seem to reluctant to enact ambitious climate policy, while appearing to be not too bothered about substantially changing the very thing that is vital to our existence on this planet; our climate?
To me, there are 3 main reasons why climate change presents a threat that is unlike anything we’ve really faced before:
- It’s irreversible on human timescales: Without some kind of as yet undeveloped negative emission technology, climate change is essentially irreversible on relevant timescales. At any instant in time, the best we can do is stop it from getting any worse. In fact, given that we can’t immediately halt all emissions, we can’t even do this. So, if we get to the point where the impacts are now obviously severely negative, all we can do is bring emissions down as fast as we possibly can, and try to avoid it getting too much worse.
- It could be large: We have the potential to emit enough to increase global average surface temperatures by more than 4oC, and more than double this in places like the Arctic. This is a substantial change in temperature. This is similar to the difference between a glacial, when mile-thick ice sheets covered parts of North America and Europe, and an inter-glacial, when the only ice sheet in the Northern Hemisphere is the Greenland ice sheet. Global warming of more than 4oC will almost certainly be a substantial change to our climate and it seems very unlikely that the impacts of such a change won’t be severely negative.
- It’s fast: In the past, most comparable changes to our climate happened over periods of thousands of years. The warming/cooling during the Milankovitch cycles typically took a few thousand years. The CO2 release associated with the Paleocene-Eocene Thermal Maximum (PETM) is also thought to have taken thousands of years. We’re doing this on the timescales of ~100 years. Not only does this mean that it will be more difficult for ecosystems to respond, and survive, but we’re rapidly perturbing a complex, non-linear system. We shouldn’t be surprised if something unexpected occurs.
So, as much as I think that some of the current narratives are too extreme, I also think that quite a lot of the mainstream narratives are too relaxed and seem to imply that we shouldn’t do anything too ambitious. I really do hope that we can effectively address this by just relying on mainstream politics and economics. I’m becoming less and less convinced that we can.