4 ms·

>At present, the rate of extinction of species is estimated at 100 to 1,000 times higher than the "base" or historically typical rate of extinction (in terms of

by hwillis 10y ago

>At present, the rate of extinction of species is estimated at 100 to 1,000 times higher than the "base" or historically typical rate of extinction (in terms of the natural evolution of the planet) and also the current rate of extinction is, therefore, 10 to 100 times higher than any of the previous mass extinctions in the history of Earth. From wikipedia, Holocene extinction. By what other metric could you possibly define "killing the planet" than killing the life on it? I hate this argument because it feels like moving goalposts. For one thing, I don't think its hyperbolic to say that an uninhabitable planet is dead. It's dead as far as it matters to us. Moreover its so hard to read something like that and not feel like the message is "Don't worry, it'll be okay". If life is reduced back to single cells, is that okay? Will the planet still not be dead? If there is still water and organic molecules, so that life may evolve in the coming millions of years, is the planet still alive? Due directly to human actions, species are dying faster than they ever have. Global warming has the potential to erase more species than ever before. Given the speed it's happening at, it may be a very real possibility that plants will not be able to adapt to changing conditions. Given that, it may be a very real possibility that the overwhelming death will cause runaway greenhouses faster than new plant and ocean life can reverse it, which would end all life on earth. Life on earth would probably survive a nuclear holocaust. If you wanted to have the beast chance of permanently killing all life on this planet, this isn't far off from how you would do it. Push as much co2 as possible into the air as quickly as possible to change global conditions enough to kill all plants at the same time. If you just try to nuke everything, you'll leave a niche that other organisms will expand into. It's like antibiotics- you can't take just one huge pill, you need to keep taking them to make sure absolutely nothing survives. Saying we aren't killing the earth is like watching someone that is getting stabbed repeatedly and saying he still has blood left.

lambdadmitry 10y ago
>Push as much co2 as possible into the air as quickly as possible to change global conditions enough to kill all plants at the same time This makes no sense. How exactly an abundance of CO2 will "kill all plants" given that they are thriving on it? Let's say temperature rises further, like +10C rise. Desertification may kill some plants, sure. In the meantime, huge swaths of Siberia and Canada will stop being permafrost and transform back into thriving bogs, marshes and forests. Moreover, there were times on Earth with widely higher temperatures. We are talking thousands of ppm of CO2 in the air and tropical flora on Antarctica. This didn't "end all life on Earth" at all.
- 0xcafecafe 10y ago
  As quickly as possible is the key. In the past any changes in temperature were much more gradual.
  - lambdadmitry 10y ago
    What mechanism for "killing all plants" through sudden atmospheric CO2 increase do you have in mind?
    - hwillis 10y ago
      I'm just saying that the biggest, most sudden, longest lasting change in habitability would be made with CO2. The temperature change is what kills the plants, not CO2. It's a bigger temperature change than an asteroid impact and lasts longer. It's like setting up a bomb, and it has multiple stages. You load co2 into the air until the bomb goes off, causing enough temperature change to cause large desertification. That releases even more stored carbon. That triggers the polar melt feedback, which triggers the permafrost melts, which triggers even more deforestation, which triggers wildfires and weather, which trigger even more polar melting, which wrecks ocean circulation, which fires the clathrate gun, and suddenly there are a handful of species in an earth that is set to random and they will inevitably die out.
  - mirimir 10y ago
    We're already rather close to "as quickly as possible" :( But plant life? Are you thinking phytoplankton?
    - hwillis 10y ago
      Well, for why specifically you'd do it like that: Loading up CO2 in the atmosphere gives you a delayed action on all of this. It's not the CO2 directly, its the fact that you can just start investing into a sudden, massive change easily and then have it all take off exponentially. If you instead pumped a toxin into the air, you would kill a great deal of things right away but as the concentration of poison rose they would develop a resistance. Thats the slow, traumatic burn, which is global but survivable with enough biodiversity. If you nuked everything, that would kill almost everything on earth but after a couple decades it'll be relatively survivable again. Life only has to stick around a little bit- spores and seeds is safe places, that by some freak coincidence managed to survive the radiation. Also survivable. With CO2, nothing happens until suddenly it does. There is a massive change in temperature that kills off biodiversity at a rate higher than ever before- we haven't even hit significant changes and we're experiencing this already. Then, once the biosphere is vulnerable, it gets hit with millenia of instability and extreme problems. There might be pockets that are shielded from this- if they sustained large, diverse populations through the massive initial changes. It's like the KT extinction on steroids. KT was ~10,000 years- a CO2 bomb would happen even faster and last even longer.
mirimir 10y ago
Yes, major extinction event. No doubt about it. But killing off plants? Can you cite something for that? It seems to me that preventing collapse of human civilization is the thing to focus on. It's what most people will care about, right? And it's far more likely than total global ecosystem collapse. I mean, we may see the first signs within a few years. The "end of all life on this planet" is something that humanity will never get near, because it'll be long gone before it happens.
- hwillis 10y ago
  The next sentence in the page is "It is also the only known mass extinction of plants". I didn't include it because it says citation needed, though. Every scenario in which life is endangered globally involves harsh feedback loops and is therefore extremely hypothetical and unstudied, but the possibilities do exist. Climate change simulation is a best case of a best case scenario- how could you possibly account realistically for the impact of losing biodiversity on that scale? The short term problem is probably ocean acidification, although 3+ degrees will directly kill a ton of food production and plant species. Ocean acidification is usually thought of in terms of corals and shellfish but it can also lead to a collapse of the ocean food chain when nearly all zooplankton die. Oceanic plants can survive acidic conditions and will thrive without predators or competition, but that leaves out the fact that the ocean will now be full of dead, rotting things. There are an incredible number of ways that scenario can become a nightmare. Poison by toxins, infection caused by too-rapid growth, explosion of predators as they feed on detritus, etc. A healthy population is required to survive a huge climate change, and there are a million ways for that to go wrong. The major catastrophe would be 5+ degree warming, which has the potential to collapse current ocean circulation patterns including the nino cycle. That would cause major devastation to biodiversity, deoxygenation of the ocean, and kill most life by land area and ocean volume. Then the isolated patches of life would have to deal with extreme weather, air quality, acidity changes, water and temperature changes. The survivors would have to stabilize the biosphere and live for millions of years with an unprecedented lack of biodiversity, until they could evolve. Species die spontaneously all the time. Tasmanian devils developed contagious cancer. The Sahara used to be a jungle. The wind changed a little bit, and converted everything to sand. As the climate changes, areas will be destroyed- even if they stay green, biodiversity will be massively reduced and those places will no longer be sustainable long term. Even if rain starts falling in the Sahara, it will be decades or centuries before it grows. In a normal extinction event growth is moderated over tens or thousands of years, in a smooth transition to other species. We have a century until we reach the same changes. Say you have a field with grass, moss and cows. Geological warming kills the grass over a hundred years, and the moss slowly grows in it's place, and all is good. If anthropogenic warming kills all the grass overnight, The cows eat all the moss except for a little hidden under a rock, which is killed when a cow dies on top of it and blocks the sun. >It seems to me that preventing collapse of human civilization is the thing to focus on. It's what most people will care about, right? And it's far more likely than total global ecosystem collapse. I mean, we may see the first signs within a few years. The "end of all life on this planet" is something that humanity will never get near, because it'll be long gone before it happens. Wow, that may actually change my feelings on reading this sentiment. It's still a little horrifying that we have to wait until humans are affected, but I do understand how someone could look around and say "Yep, still looks alive to me!". If focusing on the threat to humanity engenders the threat as a whole, I'm all for it. Of course, the breakneck speed of extinction is still horrifying. Each day means hundreds of species that I will never see, and I'm already pissed about missing giant sloths. We only killed those 10,000 years ago.

by hwillis 10y ago

lambdadmitry 10y ago

>Push as much co2 as possible into the air as quickly as possible to change global conditions enough to kill all plants at the same time This makes no sense. How exactly an abundance of CO2 will "kill all plants" given that they are thriving on it? Let's say temperature rises further, like +10C rise. Desertification may kill some plants, sure. In the meantime, huge swaths of Siberia and Canada will stop being permafrost and transform back into thriving bogs, marshes and forests. Moreover, there were times on Earth with widely higher temperatures. We are talking thousands of ppm of CO2 in the air and tropical flora on Antarctica. This didn't "end all life on Earth" at all.

0xcafecafe 10y ago
As quickly as possible is the key. In the past any changes in temperature were much more gradual.
- lambdadmitry 10y ago
  What mechanism for "killing all plants" through sudden atmospheric CO2 increase do you have in mind?
  - hwillis 10y ago
    I'm just saying that the biggest, most sudden, longest lasting change in habitability would be made with CO2. The temperature change is what kills the plants, not CO2. It's a bigger temperature change than an asteroid impact and lasts longer. It's like setting up a bomb, and it has multiple stages. You load co2 into the air until the bomb goes off, causing enough temperature change to cause large desertification. That releases even more stored carbon. That triggers the polar melt feedback, which triggers the permafrost melts, which triggers even more deforestation, which triggers wildfires and weather, which trigger even more polar melting, which wrecks ocean circulation, which fires the clathrate gun, and suddenly there are a handful of species in an earth that is set to random and they will inevitably die out.
- mirimir 10y ago
  We're already rather close to "as quickly as possible" :( But plant life? Are you thinking phytoplankton?
  - hwillis 10y ago
    Well, for why specifically you'd do it like that: Loading up CO2 in the atmosphere gives you a delayed action on all of this. It's not the CO2 directly, its the fact that you can just start investing into a sudden, massive change easily and then have it all take off exponentially. If you instead pumped a toxin into the air, you would kill a great deal of things right away but as the concentration of poison rose they would develop a resistance. Thats the slow, traumatic burn, which is global but survivable with enough biodiversity. If you nuked everything, that would kill almost everything on earth but after a couple decades it'll be relatively survivable again. Life only has to stick around a little bit- spores and seeds is safe places, that by some freak coincidence managed to survive the radiation. Also survivable. With CO2, nothing happens until suddenly it does. There is a massive change in temperature that kills off biodiversity at a rate higher than ever before- we haven't even hit significant changes and we're experiencing this already. Then, once the biosphere is vulnerable, it gets hit with millenia of instability and extreme problems. There might be pockets that are shielded from this- if they sustained large, diverse populations through the massive initial changes. It's like the KT extinction on steroids. KT was ~10,000 years- a CO2 bomb would happen even faster and last even longer.

mirimir 10y ago

Yes, major extinction event. No doubt about it. But killing off plants? Can you cite something for that? It seems to me that preventing collapse of human civilization is the thing to focus on. It's what most people will care about, right? And it's far more likely than total global ecosystem collapse. I mean, we may see the first signs within a few years. The "end of all life on this planet" is something that humanity will never get near, because it'll be long gone before it happens.

hwillis 10y ago
The next sentence in the page is "It is also the only known mass extinction of plants". I didn't include it because it says citation needed, though. Every scenario in which life is endangered globally involves harsh feedback loops and is therefore extremely hypothetical and unstudied, but the possibilities do exist. Climate change simulation is a best case of a best case scenario- how could you possibly account realistically for the impact of losing biodiversity on that scale? The short term problem is probably ocean acidification, although 3+ degrees will directly kill a ton of food production and plant species. Ocean acidification is usually thought of in terms of corals and shellfish but it can also lead to a collapse of the ocean food chain when nearly all zooplankton die. Oceanic plants can survive acidic conditions and will thrive without predators or competition, but that leaves out the fact that the ocean will now be full of dead, rotting things. There are an incredible number of ways that scenario can become a nightmare. Poison by toxins, infection caused by too-rapid growth, explosion of predators as they feed on detritus, etc. A healthy population is required to survive a huge climate change, and there are a million ways for that to go wrong. The major catastrophe would be 5+ degree warming, which has the potential to collapse current ocean circulation patterns including the nino cycle. That would cause major devastation to biodiversity, deoxygenation of the ocean, and kill most life by land area and ocean volume. Then the isolated patches of life would have to deal with extreme weather, air quality, acidity changes, water and temperature changes. The survivors would have to stabilize the biosphere and live for millions of years with an unprecedented lack of biodiversity, until they could evolve. Species die spontaneously all the time. Tasmanian devils developed contagious cancer. The Sahara used to be a jungle. The wind changed a little bit, and converted everything to sand. As the climate changes, areas will be destroyed- even if they stay green, biodiversity will be massively reduced and those places will no longer be sustainable long term. Even if rain starts falling in the Sahara, it will be decades or centuries before it grows. In a normal extinction event growth is moderated over tens or thousands of years, in a smooth transition to other species. We have a century until we reach the same changes. Say you have a field with grass, moss and cows. Geological warming kills the grass over a hundred years, and the moss slowly grows in it's place, and all is good. If anthropogenic warming kills all the grass overnight, The cows eat all the moss except for a little hidden under a rock, which is killed when a cow dies on top of it and blocks the sun. >It seems to me that preventing collapse of human civilization is the thing to focus on. It's what most people will care about, right? And it's far more likely than total global ecosystem collapse. I mean, we may see the first signs within a few years. The "end of all life on this planet" is something that humanity will never get near, because it'll be long gone before it happens. Wow, that may actually change my feelings on reading this sentiment. It's still a little horrifying that we have to wait until humans are affected, but I do understand how someone could look around and say "Yep, still looks alive to me!". If focusing on the threat to humanity engenders the threat as a whole, I'm all for it. Of course, the breakneck speed of extinction is still horrifying. Each day means hundreds of species that I will never see, and I'm already pissed about missing giant sloths. We only killed those 10,000 years ago.