9 ms·

Earth to warm more quickly, new climate models show (By 2100, could rise 6.5C)

50 points by consumer451 7y ago

makerofspoons 7y ago
In a world with such high climate sensitivity, is there still a realistic pathway to an acceptable outcome? SSP1 2.6 was already highly optimistic and with these two new models even it doesn't keep us below 2 degrees.
- trevyn 7y ago
  Perhaps it’s time to start considering how to choose to live given unacceptable outcomes.
  - consumer451 7y ago
    > Perhaps it’s time to start considering how to choose to live given unacceptable outcomes. Maybe I am misunderstanding your statement, but to which period of time are you referring to? Your lifetime? 3 generations? The long now includes a non-zero probability of a collapse of atmospheric oxygen, and complete human extinction within ~3600 years. [0] [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5138252/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5138252/
    - AbrahamParangi 7y ago
      I may be misunderstanding it but that paper reads as completely ridiculous. We haven’t had a hypoxic atmosphere in the history of the earth since the evolution of photosynthesis (that’s a 2 Billion Year track record). The support for the plausibility of the author's hypothesis is that if you fit a parabola to the data over a certain time window, you get 100% decrease in atmospheric oxygen in a few thousand years?? That model is just nuts. By the same token it predicts we will have negative oxygen shortly thereafter.
      - consumer451 7y ago
        I would love to have someone convince me that this paper is utter rubbish, so I really appreciate your comment. I am also likely a bit annoying as I don't have a science background. However, you said: > We haven’t had a hypoxic atmosphere in the history of the earth since the evolution of photosynthesis (that’s a 2 Billion Year track record). This research seems to disagree, doesn't it? [0] > Climate change triggered by volcanic greenhouse gases is hypothesized to have caused the largest mass extinction in Earth’s history at the end of the Permian Period (~252 million years ago). Geochemical evidence provides strong support for rapid global warming and accompanying ocean oxygen (O2) loss, but a quantitative link among climate, species’ traits, and extinction is lacking. To test whether warming and O2 loss can mechanistically account for the marine mass extinction, we combined climate model simulations with an established ecophysiological framework to predict the biogeographic patterns and severity of extinction. Those predictions were confirmed by a spatially explicit analysis of the marine fossil record. [0] https://science.sciencemag.org/content/362/6419/eaat1327 https://science.sciencemag.org/content/362/6419/eaat1327
        AbrahamParangi 7y ago
        See [0] for atmospheric oxygen levels over time. That dip from ~35% to ~15% atmospheric oxygen corresponds approximately to the permian extinction (~250 mya). My understanding is that there have been a number of oceanic hypoxic/anoxic events[1] in the history of the planet but that atmospheric oxygen levels have been relatively high since the oxygen holocaust[2]. [0]https://www.pnas.org/content/pnas/96/20/10955/F2.large.jpg https://www.pnas.org/content/pnas/96/20/10955/F2.large.jpg [1]https://en.wikipedia.org/wiki/Anoxic_event#Anoxic_events_in_Earth's_history https://en.wikipedia.org/wiki/Anoxic_event#Anoxic_events_in_... [2]https://en.wikipedia.org/wiki/Great_Oxidation_Event https://en.wikipedia.org/wiki/Great_Oxidation_Event
        gus_massa 7y ago
        In the first article, fitting that data with a parabola+trigonometric is a very big red flag. The error interval for the quadratic coefficient must be huge, but I can't find it. It may be fit with a line+trigonometric to get some approximation for the next few years (10? 100?). With a line you get 50000 years to the 0 oxygen level, that is less alarmist than 3600 years. Also, without a good model it's a bad idea to extend these projections too much. There are a lot of natural process that depend on the concentration of oxygen and will change. For example, under 15%-10% concentration of oxygen you can't burn wood so you solve the problem of forest fires https://en.wikipedia.org/wiki/Limiting_oxygen_concentration https://en.wikipedia.org/wiki/Limiting_oxygen_concentration
Scarblac 7y ago
Maybe only Peak Oil can save us. How much carbon is there? Surely we can't continue unabated indefinitely?
- Ancalagon 7y ago
  With new tech like Fracking, there's a lot of un-tapped resources still unfortunately :/
  - consumer451 7y ago
    Indeed. My intuition here is that climate change is an investment problem at this point. The technological solutions already exist. How do we convince all investors to walk away from a nearly guaranteed and superb return? This is the main problem which we currently face in my view.
    - rmilejczz 7y ago
      By hampering the viability of non renewables via a steep carbon tax, read more here: www.forbes.com/sites/howardgleckman/2018/10/10/bill-nordhaus-the-nobel-prize-climate-change-and-carbon-taxes/ The real barrier is making something like this policy imo
      - Scarblac 7y ago
        Or just making them illegal outright. But the whole world has to participate...
narratives 7y ago
Curious if anyone here has evaluated any of these models? I’ve done a cursory search and haven’t found a source to play with. I’m curious to know what variables were included, what variables were excluded, how the future is being predicted, and to what degree the creators any of these models have been accurate in predicting the future previously. Does anyone have a good explanation as to why it’s prudent to attempt to predict anything about anything 80 years in the future? Also curious if there is evidence of predicting the future in any field. If so, I’m wondering what the accuracy rate is one month out, one year out, five years out, etc. I’ve done some modeling with sales data, trying to predict demand in a given market based on a series of variables. The issue is how much weight to put on each variable. With lots of market research and historical data, we were able to get decent estimates a couple of months in the future. Beyond that? It was complete speculation. Especially if we missed an important variable, which is common, since its impossible to know what variables will (and won’t) be relevant in the future. I imagine climate modeling is more complex than my sales models, meaning more variables that were included, more variables that were excluded (especially the ones that are unknown unknowns), and a much larger margin for error (especially as time increases). I raise this as I haven’t seen any push back from the HN community on articles like this. Not sure if I’m missing something, if it’s political bias, or a fear of ostracized for questioning these reports. Either way, I’d be fascinated to see some deeper analysis on the topic from the minds on this forum. Have humans ever created a complex model that has enabled us to predict the future with any degree of accuracy? If so, how far into the future and with what degree of accuracy? If not, what is the purpose of a model extrapolated out to 2100? Trying to imagine when technology will reach X milestone (AGI, for example) reminds me that it’s probably wise to be less sure of our predictions. The last US presidential election reminded me of this too.
- makerofspoons 7y ago
  The DOE Energy Exascale Earth System Model is on GitHub: https://github.com/E3SM-Project/E3SM https://github.com/E3SM-Project/E3SM Here is some analysis of how the predictions made by some climate models have done: https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming https://www.carbonbrief.org/analysis-how-well-have-climate-m... They have done a remarkable job since the 1970s.
slowhand09 7y ago
A Pinatubo, Laki, or Krakatau event can easily move the ground truth of climate change.
rekabis 7y ago
And the really scary thing is that anything above +8℃ has a very real chance of flipping the planet into a Venus Scenario. Recent work has shown that the Earth sits at the very inner edge of the solar system’s habitable zone. As the sun has aged across billions of years and burned through its fuel, it has heated up and moved the zone outward. As such, the planet could have had higher greenhouse gas levels in the past with life still surviving, but it cannot have such levels now without life dying and the planet becoming a second Venus. At +8℃, equatorial cloud cover becomes impossible to generate, and the amount of oceanic heating accelerates. Methyl Hydrates begin boiling off everywhere, and it becomes too hot to live between the 60th parallels - humanity (or what’s left of it) must pack itself around the poles to survive. At some point, the amount of greenhouse gas creation exceeds the ability of life to counteract said gases, and things heat up until all life on the planet dies.
- spodek 7y ago
  The scariest thing to me is that people think their actions won't make a difference. I was speaking to an organization about reducing its flying. In the spring they wouldn't consider it. One 16-year-old girl, Greta Thunberg, sailing across the Atlantic put the initiative on the table. She didn't plan to influence that organization but she did. We all have that potential. I've given one TEDx talk on environmental leadership http://joshuaspodek.com/my-tedx-talk-is-online-find-your-delicious http://joshuaspodek.com/my-tedx-talk-is-online-find-your-del... with a second in a few weeks https://www.tedxwaltham.com/tedxwaltham-2019 https://www.tedxwaltham.com/tedxwaltham-2019. My podcast http://joshuaspodek.com/podcast http://joshuaspodek.com/podcast is creating role models among globally renowned people. I've become somewhat of a role model -- in my fourth year of not flying, I haven't filled a load of trash in over a year, I pick up litter every day -- and people write me to tell me they're doing it, as are their friends. These results aren't enough, and some disasters will happen, but each person's actions contribute, including yours -- mostly by leading others to contribute too.
- Richard_East 7y ago
  https://en.wikipedia.org/wiki/Stratospheric_aerosol_injection https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio... https://en.wikipedia.org/wiki/Iron_fertilization https://en.wikipedia.org/wiki/Iron_fertilization

50 points by consumer451 7y ago

In a world with such high climate sensitivity, is there still a realistic pathway to an acceptable outcome? SSP1 2.6 was already highly optimistic and with these two new models even it doesn't keep us below 2 degrees.

trevyn 7y ago
Perhaps it’s time to start considering how to choose to live given unacceptable outcomes.
- consumer451 7y ago
  > Perhaps it’s time to start considering how to choose to live given unacceptable outcomes. Maybe I am misunderstanding your statement, but to which period of time are you referring to? Your lifetime? 3 generations? The long now includes a non-zero probability of a collapse of atmospheric oxygen, and complete human extinction within ~3600 years. [0] [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5138252/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5138252/
  - AbrahamParangi 7y ago
    I may be misunderstanding it but that paper reads as completely ridiculous. We haven’t had a hypoxic atmosphere in the history of the earth since the evolution of photosynthesis (that’s a 2 Billion Year track record). The support for the plausibility of the author's hypothesis is that if you fit a parabola to the data over a certain time window, you get 100% decrease in atmospheric oxygen in a few thousand years?? That model is just nuts. By the same token it predicts we will have negative oxygen shortly thereafter.
    - consumer451 7y ago
      I would love to have someone convince me that this paper is utter rubbish, so I really appreciate your comment. I am also likely a bit annoying as I don't have a science background. However, you said: > We haven’t had a hypoxic atmosphere in the history of the earth since the evolution of photosynthesis (that’s a 2 Billion Year track record). This research seems to disagree, doesn't it? [0] > Climate change triggered by volcanic greenhouse gases is hypothesized to have caused the largest mass extinction in Earth’s history at the end of the Permian Period (~252 million years ago). Geochemical evidence provides strong support for rapid global warming and accompanying ocean oxygen (O2) loss, but a quantitative link among climate, species’ traits, and extinction is lacking. To test whether warming and O2 loss can mechanistically account for the marine mass extinction, we combined climate model simulations with an established ecophysiological framework to predict the biogeographic patterns and severity of extinction. Those predictions were confirmed by a spatially explicit analysis of the marine fossil record. [0] https://science.sciencemag.org/content/362/6419/eaat1327 https://science.sciencemag.org/content/362/6419/eaat1327
      - AbrahamParangi 7y ago
        See [0] for atmospheric oxygen levels over time. That dip from ~35% to ~15% atmospheric oxygen corresponds approximately to the permian extinction (~250 mya). My understanding is that there have been a number of oceanic hypoxic/anoxic events[1] in the history of the planet but that atmospheric oxygen levels have been relatively high since the oxygen holocaust[2]. [0]https://www.pnas.org/content/pnas/96/20/10955/F2.large.jpg https://www.pnas.org/content/pnas/96/20/10955/F2.large.jpg [1]https://en.wikipedia.org/wiki/Anoxic_event#Anoxic_events_in_Earth's_history https://en.wikipedia.org/wiki/Anoxic_event#Anoxic_events_in_... [2]https://en.wikipedia.org/wiki/Great_Oxidation_Event https://en.wikipedia.org/wiki/Great_Oxidation_Event
      - gus_massa 7y ago
        In the first article, fitting that data with a parabola+trigonometric is a very big red flag. The error interval for the quadratic coefficient must be huge, but I can't find it. It may be fit with a line+trigonometric to get some approximation for the next few years (10? 100?). With a line you get 50000 years to the 0 oxygen level, that is less alarmist than 3600 years. Also, without a good model it's a bad idea to extend these projections too much. There are a lot of natural process that depend on the concentration of oxygen and will change. For example, under 15%-10% concentration of oxygen you can't burn wood so you solve the problem of forest fires https://en.wikipedia.org/wiki/Limiting_oxygen_concentration https://en.wikipedia.org/wiki/Limiting_oxygen_concentration

Scarblac 7y ago

Maybe only Peak Oil can save us. How much carbon is there? Surely we can't continue unabated indefinitely?

Ancalagon 7y ago
With new tech like Fracking, there's a lot of un-tapped resources still unfortunately :/
- consumer451 7y ago
  Indeed. My intuition here is that climate change is an investment problem at this point. The technological solutions already exist. How do we convince all investors to walk away from a nearly guaranteed and superb return? This is the main problem which we currently face in my view.
  - rmilejczz 7y ago
    By hampering the viability of non renewables via a steep carbon tax, read more here: www.forbes.com/sites/howardgleckman/2018/10/10/bill-nordhaus-the-nobel-prize-climate-change-and-carbon-taxes/ The real barrier is making something like this policy imo
    - Scarblac 7y ago
      Or just making them illegal outright. But the whole world has to participate...

narratives 7y ago

Curious if anyone here has evaluated any of these models? I’ve done a cursory search and haven’t found a source to play with. I’m curious to know what variables were included, what variables were excluded, how the future is being predicted, and to what degree the creators any of these models have been accurate in predicting the future previously. Does anyone have a good explanation as to why it’s prudent to attempt to predict anything about anything 80 years in the future? Also curious if there is evidence of predicting the future in any field. If so, I’m wondering what the accuracy rate is one month out, one year out, five years out, etc. I’ve done some modeling with sales data, trying to predict demand in a given market based on a series of variables. The issue is how much weight to put on each variable. With lots of market research and historical data, we were able to get decent estimates a couple of months in the future. Beyond that? It was complete speculation. Especially if we missed an important variable, which is common, since its impossible to know what variables will (and won’t) be relevant in the future. I imagine climate modeling is more complex than my sales models, meaning more variables that were included, more variables that were excluded (especially the ones that are unknown unknowns), and a much larger margin for error (especially as time increases). I raise this as I haven’t seen any push back from the HN community on articles like this. Not sure if I’m missing something, if it’s political bias, or a fear of ostracized for questioning these reports. Either way, I’d be fascinated to see some deeper analysis on the topic from the minds on this forum. Have humans ever created a complex model that has enabled us to predict the future with any degree of accuracy? If so, how far into the future and with what degree of accuracy? If not, what is the purpose of a model extrapolated out to 2100? Trying to imagine when technology will reach X milestone (AGI, for example) reminds me that it’s probably wise to be less sure of our predictions. The last US presidential election reminded me of this too.

makerofspoons 7y ago
The DOE Energy Exascale Earth System Model is on GitHub: https://github.com/E3SM-Project/E3SM https://github.com/E3SM-Project/E3SM Here is some analysis of how the predictions made by some climate models have done: https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming https://www.carbonbrief.org/analysis-how-well-have-climate-m... They have done a remarkable job since the 1970s.

slowhand09 7y ago

A Pinatubo, Laki, or Krakatau event can easily move the ground truth of climate change.

rekabis 7y ago

And the really scary thing is that anything above +8℃ has a very real chance of flipping the planet into a Venus Scenario. Recent work has shown that the Earth sits at the very inner edge of the solar system’s habitable zone. As the sun has aged across billions of years and burned through its fuel, it has heated up and moved the zone outward. As such, the planet could have had higher greenhouse gas levels in the past with life still surviving, but it cannot have such levels now without life dying and the planet becoming a second Venus. At +8℃, equatorial cloud cover becomes impossible to generate, and the amount of oceanic heating accelerates. Methyl Hydrates begin boiling off everywhere, and it becomes too hot to live between the 60th parallels - humanity (or what’s left of it) must pack itself around the poles to survive. At some point, the amount of greenhouse gas creation exceeds the ability of life to counteract said gases, and things heat up until all life on the planet dies.

spodek 7y ago
The scariest thing to me is that people think their actions won't make a difference. I was speaking to an organization about reducing its flying. In the spring they wouldn't consider it. One 16-year-old girl, Greta Thunberg, sailing across the Atlantic put the initiative on the table. She didn't plan to influence that organization but she did. We all have that potential. I've given one TEDx talk on environmental leadership http://joshuaspodek.com/my-tedx-talk-is-online-find-your-delicious http://joshuaspodek.com/my-tedx-talk-is-online-find-your-del... with a second in a few weeks https://www.tedxwaltham.com/tedxwaltham-2019 https://www.tedxwaltham.com/tedxwaltham-2019. My podcast http://joshuaspodek.com/podcast http://joshuaspodek.com/podcast is creating role models among globally renowned people. I've become somewhat of a role model -- in my fourth year of not flying, I haven't filled a load of trash in over a year, I pick up litter every day -- and people write me to tell me they're doing it, as are their friends. These results aren't enough, and some disasters will happen, but each person's actions contribute, including yours -- mostly by leading others to contribute too.
Richard_East 7y ago
https://en.wikipedia.org/wiki/Stratospheric_aerosol_injection https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio... https://en.wikipedia.org/wiki/Iron_fertilization https://en.wikipedia.org/wiki/Iron_fertilization