Comment by nostrademons
8 years ago
Nah, the problem is self-limiting. If global warming reduces the carrying capacity of the environment, people will die. Dead people don't use resources; their bodies are returned to the environment by decomposers, where they will provide fertilizer for trees and other plants, which will grow even more abundantly because of the enhanced CO2 levels. Eventually the earth reaches a new equilibrium at a somewhat higher temperature.
Most people don't want to die, and so we have a self-interested argument for not destroying our environment. But we're at the top of the food chain - well before there's a lasting impact on the earth's ability to sustain life, we'll all be dead. It's the height of hubris to believe we have the ability to effect lasting change on the earth's environment that won't disappear once we do.
It's not true that a stable equilibrium is always reached. It's also possible that irreversible changes are set into motion which shift the equilibrium so far away from livability that humans cannot survive.
See, for instance, https://en.m.wikipedia.org/wiki/Clathrate_gun_hypothesis
What kind of time scales does this suggest?
> A study based on a coupled climate–carbon cycle model (GCM) assessed a 1000-fold (from <1 to 1000 ppmv) methane increase - within a single pulse, from methane hydrates (based on carbon amount estimates for the PETM, with ~2000 GtC), and concluded it would increase atmospheric temperatures by >6 °C within 80 years
Am I reading this right that it would take 80yrs to get to +6c, so it would still be a gradual increase? Is it an exponential increase?
Anyone recommend a documentary about this?
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This has been happening throughout history of Earth. Just look at all the ice ages (including the most recent so called little ice age).
Just cca 11,000 years ago, without any human intervention (nobody driving SUVs around back then), temperature has risen dramatically which caused massive ice sheets on top of North America and Europe to melt. This caused sea levels to rise by 120 meters, swallowing an area of land larger than China and Europe combined.
Until this day we still don't know what caused that (and it seems to be a reoccurring event as it has happened multiple times). The last time it happened it has caused extinction of most of megafauna (with some remnants surviving in Africa as it was least affected).
We are struggling to cope with sea levels rising by 1-2mm per year. Imagine if they rose by 120m in couple of years. All coastal mega cities - NYC, SF, Tokyo etc would be underwater completely.
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.
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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.
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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
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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.
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I hear the eco-nihilist party is polling excellently, pretty soon everyone will see the folly of trying to improve anything ever.
Too bad the people who die in the name of "carrying capacity"always tend to be brown and poor.
LOL. Sigh. Why does global warming attract this particular brand of sophistry all the time?
"President, what's your solution to the North Korean nukes?"
"Nothing to worry: the problem is self-limiting. If they start a nuclear war, billions will die, and then the survivors will be too poor to build any more nuclear weapons, so naturally there will be no more nuclear wars."
"But what about Puerto Rico? When are the aids coming?"
"The problem is self-limiting. If we do nothing, most of them will die or simply move to somewhere else, and then next time another hurricane hits there will be less people to die!"
The people most likely to die are the lowest emitters.
Remarkably blasé and somewhat nihilistic.