Comment by jacobolus
8 years ago
It seems that we could be headed for a mass extinction, whether or not humans manage to survive thousands of years longer.
We aren’t going to entirely destroy life on the planet, which will eventually recover great diversity (speciation to fill new ecological niches in some new stable equilibrium) within a few million years after we’re gone, but it will look significantly different than what we are familiar with.
That’s not much consolation to people who feel attached to what human societies and cultures we have all spent a lot of effort developing.
This issue is too political for normal people to properly understand. I don't mean to offend you personally but there's little value in the feelings of someone who's been immersed in a social atmosphere of global warming propaganda, calls to action, and pressure to shut down dissenting voices. Even scientists can't safely publish work on positive effects of climate change or areas where it's not as bad as previously thought without littering their papers with defenses of "but it's still bad".
Your GP said "we must" do some things. No, there isn't a single obvious best answer. We don't know what the longer term effects will be and whether building protection will be enough or not - or enough to pay for their useful life. We don't have accurate science for that. Even if we did, we've still got hundreds of years to prepare, and importantly, future money to spend on it, which is cheaper than spending money today because of the time value of money. Every solution costs money and it's no obvious which one is cheaper.
Where did you get the mass extinction and "entirely destroy life on the planet" ideas? I know there are frequent extinctions of insects and large mammals, but that's been going on for centuries and is nothing to do with global warming. Global warming might exacerbate that but again, I don't think we have clear predictions of whole food chain collapses.
EDIT: I see you've toned down your comment from a strong belief to a suggestion of a possibility, so the main motivation of my reply doesn't really apply now.
This reads very much like a Bjorn Lomborg type argument - along the lines of: global warming is not proven, and anyway if it does happen it may not be all bad, and even if it is bad we could better spend the money elsewhere. Personally when it comes to disturbing planetary equilibrium I'd rather err on the side of caution.
Even if 'erring on the side of caution' means killing millions of people by diverting resources that could've been used to cure diseases, solve local pollution problems, stop crime and democide, improve work safety, etc etc?
We're not talking about packing an extra sandwich for a picnic here. These things cost.
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Since we're talking about anthropocentric climate change, it's safe to assume "life" means "life as we know it". But you already knew that.
The distinction seems important to me. One has a clear definition and the other could be imagined to mean anything the reader wants. That's alright if everyone already understands and agrees with you, but it makes disagreement useless. Since climate change is so political, there are lot of exaggerations flying around, so you have to be careful.
I think I know that when you said "anthropocentric", you really meant "anthropogenic" but I really had to think hard to see if you were using a clever word to make a point about our own perception of human life. Eventually I decided it was just a spelling mistake but it took effort and I'm still not sure. So trying to be accurate is helpful if you're going for understanding rather than just expressing a feeling.
The Permian extinction was a global warming extinction. The atmosphere was methane and hydrogen sulfide. Oxygen levels dropped too low for anything to survive... read the book 'Under Green Skies' which makes the case for that.
There are reasonable people predicting that type of mass extinction will occur within our lifetime. This blog makes a pretty good argument it will happen: http://arctic-news.blogspot.com/p/extinction.html?m=1
Last global extinction event was 11,000 years ago when temperature rose drastically, ice sheets melted and sea levels rose by 120m. It killed most of megafauna. What caused that (and what caused the ice age in the first place) is still not well understood by scientists.
In my opinion, to think that human caused global warming and sea levels rising by 1.5mm per year will lead to global extinction event seems a bit far fetched when you compare it to what caused the last global extinction. The current climate changes are minuscule compared to huge climate changes (not caused by any human activity!) that happened quite recently.
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There are reasonable people...
Have they got Paul Erlich on board?
The less clear our predictions are, the more we should manage the risk.
If we've shifted planetary equilibrium far enough, we could be just "2 or 3 volcanic eruptions within a short window of time" away from accelerated feedback effects into a runaway catastrophe
If we manage to e.g. change ocean conditions enough (and the changes are already dramatic) to take out a significant proportion of the plankton in the world, it’s not going to go well for us.
What of the things that we "must" do do you actually disagree with?
We're not, actually:
https://www.theatlantic.com/science/archive/2017/06/the-ends...
I used to think that we were, and when I read that article, I kept looking for flaws in its logic or counterexamples in other press. But ultimately, it interviews a real expert, and his logic is correct: we're drawn to flashy apex predators at the top of the food web, but these species spring in and out of existence all the time, and when it comes to the fossil record, they're barely a blip. If we were actually in a mass extinction, we would be worrying about cockroaches, ants, and seaweed going extinct, not tigers and rhinos. And of course, we wouldn't be here to observe it.
That's not an argument to completely fuck up the environment, since, like I mentioned, we'll be the first to go and most people have some sense of self-preservation, let alone preservation of the human species. It is a reminder of just how insignificant we actually are on a planetary scale, and of how our cognitive biases often lead us to think that we are more important or more powerful than we actually are.
Okay.
> “I think that if we keep things up long enough, we’ll get to a mass extinction, but we’re not in a mass extinction yet, and I think that’s an optimistic discovery because that means we actually have time to avoid Armageddon,” he said. [...]
> “The only hope we have in the future,” Erwin said, “is if we’re not in a mass extinction event.”
* * *
I guess it’s a bit fuzzy where you draw the line. Perhaps mass extinction is not an inevitability and concerted global action or some technological breakthroughs could still save us, but it has an uncomfortably high likelihood considering how bad humans are at staving off uncertain long-term threats.
It's maybe worth drawing a distinction between things like "species extinction" versus "civilization collapse" and "massive reduction in carrying capacity".
I think it is much easier to have one or both of the latter outcomes in the med term (the next few hundred years, say) without it necessarily ending in human extinction.
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