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This is how the world ends. Not with a bang or whimper, but with a fart. https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis https://en.wikipedia.org/wiki/C

This is how the world ends. Not with a bang or whimper, but with a fart. https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

Retric 8y ago
Global warming is bad in terms of infrastructure, but would not make earth uninhabitable or anything.
- starbeast 8y ago
  Is predicted to made several large populated areas uninhabitable due to the wet bulb temperature rising past the limits of human survivability for much of the year.
- jellicle 8y ago
  If we burn or release the ocean methane deposits for any reason, most of the Earth's land surface would be uninhabitable to humans, meaning all unprotected humans would die. Maybe there would still be habitable zones near the poles. Not certainly, but maybe.
  - Retric 8y ago
    [Citation needed] because as near as I can find that's really not on the table. Remember temperature is very nonlinear, eventually adding atmospheric methane has a reduced effect as their is enough of it to block the spectra and adding more does little.
- adrianN 8y ago
  There is a chance that the oceans will warm more quickly than the phyplankton can survive. A massive die-off of phytoplankton would be catastrophic. It's our main source of oxygen and the basis for the marine food chain.
  - Retric 8y ago
    Source? Ocean phyplankton are very resistant to temperature changes.
    - adrianN 8y ago
      Phytoplankton is already declining: > We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ∼1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. https://www.nature.com/articles/nature09268 https://www.nature.com/articles/nature09268
      - Retric 8y ago
        If you could find areas where warm waters killed them off that would be something, but some species of phytoplankton are known to survive to 40+°C. "The 1980s saw a rapid increase in phytoplankton biomass in the North-east Atlantic. We now know this dramatic change was part of a regime shift—a climate-driven stepwise change in the structure and functioning of the north-east Atlantic marine ecosystem." https://www.mba.ac.uk/are-marine-phytoplankton-decline https://www.mba.ac.uk/are-marine-phytoplankton-decline Anyway, they are not simply being killed of in the warmest waters. Climate change means changes in ocean current circulation and other effects beyond simple changes in temperature.
- specialist 8y ago
  What is the survivable level of atmospheric carbon? I don't mean civilization as we know it. I mean mammals, specifically humans. -- The tundra is thawing with no way to halt, much less reverse. Not an expert, but IIRC it holds 3x the carbon of total anthropogenic sources. That's bad, right? Ocean acidification will remove that source of food. I don't know if it stops being a carbon sink at some point. What happens when the microscopic critters (plankton), which consumed carbon, can no longer survive? Deforestation and desertification is transferring terrestrial carbon to the air. How much of that burns? Most of it? Those three processes are now in a positive feedback loop. With no apparent inhibitors. And humans keep consuming fossil fuels. Juicing the feedback loop. What's projected atmospheric carbon of all those combined? 1200ppm? 2000ppm? Higher? Ok, that's pretty bleak, right? Is that a mass extinction event level of bleakness? -- Now what happens if even a fraction of the frozen methane gets released? Which critters are capable of surviving that? -- Edit: I couldn't remember the values for the hottest period. Eocene Epoch had 4000ppm. https://en.wikipedia.org/wiki/Eocene#Atmospheric_greenhouse_gas_evolution https://en.wikipedia.org/wiki/Eocene#Atmospheric_greenhouse_... And not everything died. So maybe there's some hope.
  - Retric 8y ago
    “The Center for Disease Control has designated 100,000 ppm of carbon dioxide as life-threatening.” So, that’s a very long way past 4,000. The workplace safty limit is set at 5,000 for 8 hours which is considered a very conservative and safe estimate. Honestly, if we where looking at 40,000 I would be very concerned. But that’s vastly above anyone’s projections. So, CO2 is not going to be a direct threat to us. It’s knock on effects that’s the issue. PS: Remember people can survive with significantly reduced lung capacity. Breathing is really important in terms of evolution so the ‘safty factor’ is huge.

This is how the world ends. Not with a bang or whimper, but with a fart. https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

Retric 8y ago

Global warming is bad in terms of infrastructure, but would not make earth uninhabitable or anything.

starbeast 8y ago
Is predicted to made several large populated areas uninhabitable due to the wet bulb temperature rising past the limits of human survivability for much of the year.
jellicle 8y ago
If we burn or release the ocean methane deposits for any reason, most of the Earth's land surface would be uninhabitable to humans, meaning all unprotected humans would die. Maybe there would still be habitable zones near the poles. Not certainly, but maybe.
- Retric 8y ago
  [Citation needed] because as near as I can find that's really not on the table. Remember temperature is very nonlinear, eventually adding atmospheric methane has a reduced effect as their is enough of it to block the spectra and adding more does little.
adrianN 8y ago
There is a chance that the oceans will warm more quickly than the phyplankton can survive. A massive die-off of phytoplankton would be catastrophic. It's our main source of oxygen and the basis for the marine food chain.
- Retric 8y ago
  Source? Ocean phyplankton are very resistant to temperature changes.
  - adrianN 8y ago
    Phytoplankton is already declining: > We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ∼1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. https://www.nature.com/articles/nature09268 https://www.nature.com/articles/nature09268
    - Retric 8y ago
      If you could find areas where warm waters killed them off that would be something, but some species of phytoplankton are known to survive to 40+°C. "The 1980s saw a rapid increase in phytoplankton biomass in the North-east Atlantic. We now know this dramatic change was part of a regime shift—a climate-driven stepwise change in the structure and functioning of the north-east Atlantic marine ecosystem." https://www.mba.ac.uk/are-marine-phytoplankton-decline https://www.mba.ac.uk/are-marine-phytoplankton-decline Anyway, they are not simply being killed of in the warmest waters. Climate change means changes in ocean current circulation and other effects beyond simple changes in temperature.
specialist 8y ago
What is the survivable level of atmospheric carbon? I don't mean civilization as we know it. I mean mammals, specifically humans. -- The tundra is thawing with no way to halt, much less reverse. Not an expert, but IIRC it holds 3x the carbon of total anthropogenic sources. That's bad, right? Ocean acidification will remove that source of food. I don't know if it stops being a carbon sink at some point. What happens when the microscopic critters (plankton), which consumed carbon, can no longer survive? Deforestation and desertification is transferring terrestrial carbon to the air. How much of that burns? Most of it? Those three processes are now in a positive feedback loop. With no apparent inhibitors. And humans keep consuming fossil fuels. Juicing the feedback loop. What's projected atmospheric carbon of all those combined? 1200ppm? 2000ppm? Higher? Ok, that's pretty bleak, right? Is that a mass extinction event level of bleakness? -- Now what happens if even a fraction of the frozen methane gets released? Which critters are capable of surviving that? -- Edit: I couldn't remember the values for the hottest period. Eocene Epoch had 4000ppm. https://en.wikipedia.org/wiki/Eocene#Atmospheric_greenhouse_gas_evolution https://en.wikipedia.org/wiki/Eocene#Atmospheric_greenhouse_... And not everything died. So maybe there's some hope.
- Retric 8y ago
  “The Center for Disease Control has designated 100,000 ppm of carbon dioxide as life-threatening.” So, that’s a very long way past 4,000. The workplace safty limit is set at 5,000 for 8 hours which is considered a very conservative and safe estimate. Honestly, if we where looking at 40,000 I would be very concerned. But that’s vastly above anyone’s projections. So, CO2 is not going to be a direct threat to us. It’s knock on effects that’s the issue. PS: Remember people can survive with significantly reduced lung capacity. Breathing is really important in terms of evolution so the ‘safty factor’ is huge.