Thanks for the reply. If you don’t mind my adding a few more thoughts:
I agree temperature can increase superlinearly past a certain level of emissions. However, I expect the linear regime to continue for a while. From note (6.93) of What We Owe to the Future (WWOF) (see here; emphasis below added by me):
and then there’s some estimates of temperature effects of all the tipping elements you listed … tipped. But temperature effects on temperature, not the effects of the changed systems on the land, oceans, or atmosphere. Looking at those numbers, I have some serious doubts. For example, if you shut off the AMOC, you change ocean circulation such that warming occurs off continental shelves, triggering release of hydrates on those shelves. Globally, there’s more than is needed to raise GAST by 0.5C. There’s more accessible and releasable from just the East Siberian Arctic Shelf, 1C-2C GAST from there alone, if it’s an abrupt release of mostly methane.
If the Greenland Ice Sheet were to collapse, the accompanying sea level rise would be more than 7 meters. Off the top of my head, that would flood some countries, make floods so drastic in others that farming ceases because of saltwater inundation, and flood out most coastal cities around the world. Global farming productivity would take a hit because of loss of low-lying countries. Saltwater would infiltrate groundwater supplies in more places, and reduce the fertility of land near rivers, reducing farming productivity further. That’s one tipping point considered in isolation. EDIt: Those effects would begin with strength around 1-2 meters of rise, I estimate.
If you’re writing about the collapse of the West Antarctic Ice Sheet, that’s near-term, and 10+ feet of sea level rise. I don’t know how you feel about the civilizational impacts of an additional 10+ feet of sea level rise, but you can’t feel that good about it, and at that point, the Antarctic would not stop melting. It holds 50 meters plus of sea level rise in it.
And that’s just one problem. Jet stream instability? That’s connected heat domes across the Northern Hemisphere, extreme weather events like what happened in the UK this year, but much worse, for example, enough to trigger a multi-breadbasket failure. Shifting the monsoons? Well, that could dry out land over Asia and South America, reducing farming productivity, killing forests,desertifying land, collapsing land biological pumps, which currently absorb some 30% of anthropogenic CO2 production. Those effects would be irreversible in the short term. Carbon dumped from existing land suffering fires or drought would go into the atmosphere, adding to anthropogenic sources. The ocean would be what’s left to absorb CO2, some 25%+ of our CO2 production (EDIT: or more).
But then the problems become too big. The AMOC has stopped, land sinks of carbon are gone, methane hydrates globally are melting out, permafrost is melting out abruptly, ocean PH in the productive zones has dropped because of changed circulation, ocean heating and freshening and CO2 absorption has collapsed all fisheries, starting in the Arctic, and some phytoplankton species are dead, with others present but in smaller amounts, though that’s a guess. The ocean’s biological pump is collapsed, and the ocean is dumping more carbon into the atmosphere. In parallel, the 6th great extinction over and ours is threatening.
I just don’t think that the impacts of those tipping elements falling was thought through very well by the WWOTF research. Their analysis reverses the relevant importance of GAST, apparently. It’s not that higher GAST is nonlinearly bad in amplifying itself (though I think if all those tipping points fall, you could be looking at 20C GAST rise or more). What is bad about higher GAST is that it effects those tipping elements as it does, nonlinearly, and at fairly low temps, 2C-5C GAST rise, mostly. The consequences of the tipping elements falling are disastrous. Most people die. Most species go extinct. Most land is uninhabitable. That’s what the fall of those tipping elements means.
I believe it takes patience and bottom-up thinking to consider building a town on a melted permafrost landscape still oozing methane and developing sink holes with constant simmering fire appearing on any vegetation, or in a desert with 55C-60C temps a lot of the year or rocky areas with no groundwater, no meltwater, no rivers, and little or no rain, or on a coast subject to frequent extreme weather, toxic algae blooms, and pollutant-contaminated jellyfish die-offs, when they’re around at all.
I’ve read before that geologic time shows that species survived high temperature changes, and so there won’t be a 6th great extinction, but it is already taking place, our activities outside global warming contribute to it, and in any case relevant temperature changes from the geologic past occurred over much longer than a few hundred years, giving species time to adapt.
The lesson in climate science and given in public discussion and media coverage of climate change is, that we don’t want to go past 1.5C GAST rise. Here’s we’re looking at upwards of 3C GAST rise this century. The articles I referenced are exploring the outcomes of that rise, and its knock-on effects into the next century. The significance is the systemic effects of that GAST rise, not that the numbers are just “high” per se.
Unfortunately, I do not know much about the effects of the tipping points. I believe you know way more than I do! That being said, I can say I agree with Kemp 2022 that research on the effects of extreme climate change (> 3 ºC) has been neglected relative to non-extreme one.
You’re welcome, of course, and thank you for your courtesy in replying.
I don’t have time, money, training or resources to explore climate in more detail, but if I could, I would start with developing more sophisticated computer models that incorporate more physical processes deciding changes to tipping elements (for example, meltwater drainage on Greenland). Existing atmospheric models use a mesh that is too coarse, making predictions translate from climate to weather poorly. Ocean modeling is hopeless at current atmospheric mesh size, we need 1km meshes or better for climate models, not the much larger meshes in use for the atmosphere. Dedication of more and faster computer resources to climate modeling would be helpful.
However, different methodologies applied to develop less sophisticated models can still produce general foresight that limits or suggests available policy options to prevent climate-related crises. This runs into political interests ultimately concerned with the welfare of a small percentage of the global population, whose false sense of security and selfishness is actually in the way of preserving civilization.
Regardless, the survival of humanity, if that is what this fiasco comes to, could depend on terraforming this planet back to an 1800′s state. Well before then, we need very fine mesh computer models, as well as better understanding of ecosystems and practical means to create and quickly evolve new species. An alternative would be local-scale weather and ecosystem control, allowing a small area of land to have mild weather and favorable living conditions, allowing one city or small country to flourish, though that combination of advanced technology and a small human population might not work on its own. The trouble with humans and technology is that we are not born with the learnings of our parents, so a small population supported by technology that is magic to us, and whose ecosystem also depends on that technology, won’t last, unless we’ve locked in some AI or AL running it that understands it. That issue makes me think we’re better off with a planet that is habitable in many areas, not one with a small green zone run by some effectively alien technology. If that whole discussion seems implausible, that is because it absolutely is implausible.
While as a longtermist, I can see the value of having a small human population reached equitably through family planning over a few centuries, that should be achieved without large losses of existing global population. That means protecting against climate change catastrophe and systemic effects. Implying, for this century, degrowth and energy conservation and the end of consumerism, and less emphasis on democratization of advanced technologies. But all that has to happen soon to preserve most of the global population from early death.
I have watched Kemp’s lecture on foreseeing the end of the world. The discussion is about how to layer forecasting and foreseeing methods to improve prediction of existential crises, something still in the exploratory stages. Don’t associate my own conclusions with his, my weird opinions are my own, but I recommend his work.
You folks do a lot of forecasting, but foreseeing is worth exploring as well. I see the same forks in the road, but only foresee the negative ones as least surprising. Climate destruction is not a hopeless situation though, but not hopeless for whom living how? That’s the bigger question, and a worrisome one. There’s no solutions without compromises, particularly for utilitarians , that is, absent the longtermist “far future trillions of people” take, where current population is a just a blip anyway. And that’s why I’ve said before, only future people that will exist have moral status. Present people do have moral status. Present people matter, including those in the womb. Future people? Only if they will actually be alive at some point.
Climate destruction, as assessed by MacAskill’s book and Halstead’s analysis, is difficult to take seriously. You EA folks could use something better, considering your interest in preventing existential dangers. In general, EA’s massively underestimate the climate change threat to civilization, and appear to prefer techno-optimist solutions regardless, which multiplies environmental and resource management concerns for utilitarians when turned into policy.
Anyway, I envy your position as someone actively involved in foresight and forecasting, as well as your efforts to suggest policy. Congratulations on that opportunity! I have not looked into the climate nonprofit that you recommend, but I hope their work is good.
Thanks for the reply. If you don’t mind my adding a few more thoughts:
and then there’s some estimates of temperature effects of all the tipping elements you listed … tipped. But temperature effects on temperature, not the effects of the changed systems on the land, oceans, or atmosphere. Looking at those numbers, I have some serious doubts. For example, if you shut off the AMOC, you change ocean circulation such that warming occurs off continental shelves, triggering release of hydrates on those shelves. Globally, there’s more than is needed to raise GAST by 0.5C. There’s more accessible and releasable from just the East Siberian Arctic Shelf, 1C-2C GAST from there alone, if it’s an abrupt release of mostly methane.
If the Greenland Ice Sheet were to collapse, the accompanying sea level rise would be more than 7 meters. Off the top of my head, that would flood some countries, make floods so drastic in others that farming ceases because of saltwater inundation, and flood out most coastal cities around the world. Global farming productivity would take a hit because of loss of low-lying countries. Saltwater would infiltrate groundwater supplies in more places, and reduce the fertility of land near rivers, reducing farming productivity further. That’s one tipping point considered in isolation. EDIt: Those effects would begin with strength around 1-2 meters of rise, I estimate.
If you’re writing about the collapse of the West Antarctic Ice Sheet, that’s near-term, and 10+ feet of sea level rise. I don’t know how you feel about the civilizational impacts of an additional 10+ feet of sea level rise, but you can’t feel that good about it, and at that point, the Antarctic would not stop melting. It holds 50 meters plus of sea level rise in it.
And that’s just one problem. Jet stream instability? That’s connected heat domes across the Northern Hemisphere, extreme weather events like what happened in the UK this year, but much worse, for example, enough to trigger a multi-breadbasket failure. Shifting the monsoons? Well, that could dry out land over Asia and South America, reducing farming productivity, killing forests,desertifying land, collapsing land biological pumps, which currently absorb some 30% of anthropogenic CO2 production. Those effects would be irreversible in the short term. Carbon dumped from existing land suffering fires or drought would go into the atmosphere, adding to anthropogenic sources. The ocean would be what’s left to absorb CO2, some 25%+ of our CO2 production (EDIT: or more).
But then the problems become too big. The AMOC has stopped, land sinks of carbon are gone, methane hydrates globally are melting out, permafrost is melting out abruptly, ocean PH in the productive zones has dropped because of changed circulation, ocean heating and freshening and CO2 absorption has collapsed all fisheries, starting in the Arctic, and some phytoplankton species are dead, with others present but in smaller amounts, though that’s a guess. The ocean’s biological pump is collapsed, and the ocean is dumping more carbon into the atmosphere. In parallel, the 6th great extinction over and ours is threatening.
I just don’t think that the impacts of those tipping elements falling was thought through very well by the WWOTF research. Their analysis reverses the relevant importance of GAST, apparently. It’s not that higher GAST is nonlinearly bad in amplifying itself (though I think if all those tipping points fall, you could be looking at 20C GAST rise or more). What is bad about higher GAST is that it effects those tipping elements as it does, nonlinearly, and at fairly low temps, 2C-5C GAST rise, mostly. The consequences of the tipping elements falling are disastrous. Most people die. Most species go extinct. Most land is uninhabitable. That’s what the fall of those tipping elements means.
I believe it takes patience and bottom-up thinking to consider building a town on a melted permafrost landscape still oozing methane and developing sink holes with constant simmering fire appearing on any vegetation, or in a desert with 55C-60C temps a lot of the year or rocky areas with no groundwater, no meltwater, no rivers, and little or no rain, or on a coast subject to frequent extreme weather, toxic algae blooms, and pollutant-contaminated jellyfish die-offs, when they’re around at all.
I’ve read before that geologic time shows that species survived high temperature changes, and so there won’t be a 6th great extinction, but it is already taking place, our activities outside global warming contribute to it, and in any case relevant temperature changes from the geologic past occurred over much longer than a few hundred years, giving species time to adapt.
The lesson in climate science and given in public discussion and media coverage of climate change is, that we don’t want to go past 1.5C GAST rise. Here’s we’re looking at upwards of 3C GAST rise this century. The articles I referenced are exploring the outcomes of that rise, and its knock-on effects into the next century. The significance is the systemic effects of that GAST rise, not that the numbers are just “high” per se.
Thanks for sharing!
Unfortunately, I do not know much about the effects of the tipping points. I believe you know way more than I do! That being said, I can say I agree with Kemp 2022 that research on the effects of extreme climate change (> 3 ºC) has been neglected relative to non-extreme one.
You’re welcome, of course, and thank you for your courtesy in replying.
I don’t have time, money, training or resources to explore climate in more detail, but if I could, I would start with developing more sophisticated computer models that incorporate more physical processes deciding changes to tipping elements (for example, meltwater drainage on Greenland). Existing atmospheric models use a mesh that is too coarse, making predictions translate from climate to weather poorly. Ocean modeling is hopeless at current atmospheric mesh size, we need 1km meshes or better for climate models, not the much larger meshes in use for the atmosphere. Dedication of more and faster computer resources to climate modeling would be helpful.
However, different methodologies applied to develop less sophisticated models can still produce general foresight that limits or suggests available policy options to prevent climate-related crises. This runs into political interests ultimately concerned with the welfare of a small percentage of the global population, whose false sense of security and selfishness is actually in the way of preserving civilization.
Regardless, the survival of humanity, if that is what this fiasco comes to, could depend on terraforming this planet back to an 1800′s state. Well before then, we need very fine mesh computer models, as well as better understanding of ecosystems and practical means to create and quickly evolve new species. An alternative would be local-scale weather and ecosystem control, allowing a small area of land to have mild weather and favorable living conditions, allowing one city or small country to flourish, though that combination of advanced technology and a small human population might not work on its own. The trouble with humans and technology is that we are not born with the learnings of our parents, so a small population supported by technology that is magic to us, and whose ecosystem also depends on that technology, won’t last, unless we’ve locked in some AI or AL running it that understands it. That issue makes me think we’re better off with a planet that is habitable in many areas, not one with a small green zone run by some effectively alien technology. If that whole discussion seems implausible, that is because it absolutely is implausible.
While as a longtermist, I can see the value of having a small human population reached equitably through family planning over a few centuries, that should be achieved without large losses of existing global population. That means protecting against climate change catastrophe and systemic effects. Implying, for this century, degrowth and energy conservation and the end of consumerism, and less emphasis on democratization of advanced technologies. But all that has to happen soon to preserve most of the global population from early death.
I have watched Kemp’s lecture on foreseeing the end of the world. The discussion is about how to layer forecasting and foreseeing methods to improve prediction of existential crises, something still in the exploratory stages. Don’t associate my own conclusions with his, my weird opinions are my own, but I recommend his work.
You folks do a lot of forecasting, but foreseeing is worth exploring as well. I see the same forks in the road, but only foresee the negative ones as least surprising. Climate destruction is not a hopeless situation though, but not hopeless for whom living how? That’s the bigger question, and a worrisome one. There’s no solutions without compromises, particularly for utilitarians , that is, absent the longtermist “far future trillions of people” take, where current population is a just a blip anyway. And that’s why I’ve said before, only future people that will exist have moral status. Present people do have moral status. Present people matter, including those in the womb. Future people? Only if they will actually be alive at some point.
Climate destruction, as assessed by MacAskill’s book and Halstead’s analysis, is difficult to take seriously. You EA folks could use something better, considering your interest in preventing existential dangers. In general, EA’s massively underestimate the climate change threat to civilization, and appear to prefer techno-optimist solutions regardless, which multiplies environmental and resource management concerns for utilitarians when turned into policy.
Anyway, I envy your position as someone actively involved in foresight and forecasting, as well as your efforts to suggest policy. Congratulations on that opportunity! I have not looked into the climate nonprofit that you recommend, but I hope their work is good.