I was wanting to post a figure from a recent paper by Clark et al. called Consequences of twenty-first-century policy for multi-millennial climate and sea-level change. The figure is below, and it highlights two related things that I’ve been trying to stress for a while
- A reasonable fraction (20-30%) of what we emit will remain in the atmosphere for millenia.
- The resulting climate change will also persist for millenia.
A basic consequence of the above is that – in the absence of some kind of technological fix (which would carry risks of its own) – anthropogenically-driven climate change is irreversible on human timescales.
Hence, given that what we’re doing is likely to irreversibly change our climate for thousands of years, you’d like to think that we’d consider – long and hard – the consequences of continuing to do so. I realise that some are doing exactly this (the author’s of this paper, the IPCC, COP21, for example) but it still feels as though there is a great desire to ignore this, or even dismiss it. I’m not suggesting that deciding what to do is easy, but that’s not a reason to ignore that what we’re doing now may change our climate – potentially in severely negative (for us) ways – for thousands of years.
For all we know, we may be the only sentience in the Galaxy, maybe even in the Universe. We may be the only ones able to bear witness to the beauty of our Universe, and it may be our destiny to explore the miracle of sentience down through billions of years of the future,…
That the only known life – sentient or otherwise – in the universe, exists in a thin shell, on a small rocky planet, orbiting a pretty standard star, would seem to be something also worth considering. On the other hand, maybe this is largely irrelevant, at least in some kind of universal morality sense. There is no obvious reason why we’re morally obligated to not do something that risks our existence. At the end of the day, doing it would simply be stupid, and I would hate to be part of a generation that contributed to doing so.
I’ve been trying to think of how to end this post, but I’m somewhat struggling. It’s partly because I’m just back from a trip with the family, so am rather tired, but it’s partly because I find the moral argument difficult. It seems obvious to me that we have some kind of obligation to protect the only planet on which we can live, and that this means more than simply assuming that we can fix anything we might break. Others, however, seem to disagree.