8 ms·

If we can't figure out an engineering solution to this problem then it's game over. It always amazes me how much people and governments focus on prevention when

by fjabre 10y ago

If we can't figure out an engineering solution to this problem then it's game over. It always amazes me how much people and governments focus on prevention when it comes to climate change, knowing full well it's far too late to change anything by reducing carbon emissions. If we can't sequester these 'surplus' gases from the atmosphere then I guess you could say we don't have a chance in hell, pun intended, of surviving as a species if runaway warming becomes a reality.

philipkglass 10y ago
Artificial sulfate aerosols look like they could quickly damp positive feedbacks though of course they're no permanent fix and won't do anything to counteract ocean acidification. There are more permanent fixes possible in theory (large scale accelerated silicate weathering) but their feasibility hinges, IMO, on some rather optimistic assumptions about the future trajectory of robotics. Metaphorically speaking, we now have to consider the planetary equivalent of high-risk, high-cost surgery after mostly ignoring the planetary "stop smoking" advice experts have been giving for more than a generation. Also, any large scale sequestration effort is going to be much harder if emissions continue unabated. We're past the point where prevention alone can stabilize atmospheric CO2 but we're never past the point where further anthropogenic emissions can make the problem even worse.
- bufbupa 10y ago
  Can you elaborate on the optimistic assumptions in robotics that may enable accelerated silicate weathering? Or could you point me to some readings on the matter?
  - philipkglass 10y ago
    A search on Google Scholar for "accelerated silicate weathering" will be more informative than my comment. But here's the shortish version... Naturally occurring silicates of magnesium, calcium, sodium, and potassium are thermodynamically prone to weather to carbonates in ambient conditions, when water absorbs CO2 and passes over rocks. In the case of magnesium and calcium in particular, the weathering leads to stable solids that will not spontaneously release CO2 again. A schematic example with calcium silicate: CO2 + CaSiO3 -> SiO2 + CaCO3 Gaseous carbon dioxide and solid calcium silicate become solid silicon dioxide and calcium carbonate. Silicate weathering has multiple advantages over other carbon dioxide removal/sequestration schemes: • The end state is naturally stable. You don't have to worry about the leakiness of underground containment. • It restores the pH balance of the oceans as well as reducing radiative forcing (warming) effects. • It deals equally well with point and distributed sources of CO2 (coal plants, automobile tailpipes). • It can be located anywhere on Earth. It does not need to be adjacent to CO2 sources. • It does not require concentrated CO2 streams, but works with ambient atmospheric concentrations. Natural silicate weathering reactions dominate Earth's CO2 balance in the very long term. But they are strongly kinetically hindered in nature. After a freshly exposed rock surface has weathered to a depth of a few microns, the cation-depleted "rind" drastically slows the weathering of the remaining interior. Without human intervention, it'll take about 100,000 years for natural silicate weathering to restore the pre-industrial baseline of atmospheric CO2 concentrations. There are different ways to improve the kinetics: • Crush bulk rock to a fine sand texture, so full interior weathering finishes much faster (still takes years-to-decades, but no longer takes geological time scales). • Place crushed rock in near-shore ocean environments where mechanical wave erosion keeps removing rinds. • Place crushed rock in acidic tropical agricultural soils where it weathers faster due to low pH and elevated temperature. This also improves soil quality for growing crops. It's not explicitly included in the scholarly literature, but I say that advanced robotics are necessary because the required scale of intervention is staggering, bigger than any engineering endeavor in history. For example, the Columbia Plateau in the United States contains basalt whose alkali and alkaline earth content could bind about 20% of its own mass in CO2, after complete weathering: https://crustal.usgs.gov/geochemical_reference_standards/basaltbcr2.html https://crustal.usgs.gov/geochemical_reference_standards/bas... To neutralize the CO2 that humans emitted in 2015, about 36 billion tons (https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...), would require mining and pulverizing about 180 billion tons of Columbia Plateau basalt. That's about 60 cubic kilometers. We're in no danger of running out of plateau -- it contains more than 170,000 km^3. As for energy estimates, the Bond Work Index for crushing basalt such that 80% of particles pass a 100 micron screen is in the neighborhood of 17-20 kWh per ton: https://www.911metallurgist.com/blog/table-of-bond-work-index-by-minerals https://www.911metallurgist.com/blog/table-of-bond-work-inde... I'll add a factor of 2 for overhead to estimate the whole process energy expenditure. That would mean that using Columbia Plateau basalt, you'd expend 40 kWh per ton of basalt, about 200 kWh per ton of CO2 removed from the atmosphere. That is, energetically speaking, really good compared to schemes that try to run "combustion-in-reverse" to regenerate hydrocarbons from CO2. It's efficient enough that you could actually use coal fired power to drive the whole process and it would still be a net CO2 sink. But at 200 kWh per ton-CO2-scrubbed, it would take 7.2 billion megawatt hours to neutralize humanity's 2015 CO2 emissions. That's an annualized power of 821 gigawatts -- nearly twice the average electrical power generated in the United States. The scale is so vast that I can only imagine advanced robotic manufacturing, mining, and energy generation being up to the task. However you want to modify my baseline scenario -- smaller projects scattered around the Earth instead of one mega-project, being pickier about processing only the best rocks -- I think that the scale is still daunting. But I think it may still be possible because I see automation advancing a lot in the 21st century if we don't precipitate a civilization-ending crisis first.
    - anon1253 10y ago
      It's not the only option either. Combine that solution on a massive scale with re-forestation and (even though eventually it's CO2 neutral) it might actually make a dent. My go-to model was always: - Plant heliostat molten salt reactors in desert coastal areas [1] - Use generated heat to desalinate water - Use desalinated water to provide irrigation - Plant (potentially GMO'ed) bootstrapping organisms to create a soil (greening) - Plant trees - Rinse repeat. However, your idea makes more sense if the only goal is CO2 scrubbing. But adding the heliostat molten salt reactors in a desert might be quite feasible, they generate tons of heat, which can be translated into energy or simply mechanical force (water pressure)…and there is no shortage of silicates in the desert. [1] http://www.solarreserve.com/en/technology/molten-salt-energy-storage http://www.solarreserve.com/en/technology/molten-salt-energy...
      - philipkglass 10y ago
        Yes, re-forestation or afforestation is another scheme worth considering. It can't scale up to the extent of accelerated silicate weathering but it could reach a scale of gigatons of CO2 per year. And it could produce food, wood products, and desirable living space for humans where once there were deserts with little biomass of any kind. You need to harvest-and-bury wood (as biochar, preferably) pretty regularly if the primary goal is CO2 sequestration; otherwise the steady state is approximately equal to current mature forested areas (which store plenty of carbon in soils but aren't great at continuing to remove more from the air). Accelerated silicate weathering and "greening the deserts" are concepts that work well together, too. Mature fertile soil contains weathered minerals and organic matter. Crushing basalt can speed up the weathering part of producing soil, and provide micronutrients for plants plus a couple of important macros (phosphorus and potassium).
        SwetDrems 10y ago
        Only tangentially related, but here[0] is a video of the great reforestation program that South Korea undertook after the Korean War. They effectively transformed vast arid landscapes into healthy forests. Shows the power of a nation/people coming together with careful planning, forethought, unity, and grit can literally shape the earth. [0] https://www.youtube.com/watch?v=_3KkN8hvUCI https://www.youtube.com/watch?v=_3KkN8hvUCI
rodgerd 10y ago
> It always amazes me how much people and governments focus on prevention when it comes to climate change If the US government was actually focused on prevention, that would be a huge step up from "denying there's a problem."
- mirimir 10y ago
  I suspect that the interests driving denial are planning to ride the crash. There are probably developments in favorable locations. Land. Security. Infrastructure. Resources.
  - marcosdumay 10y ago
    Does somebody have climatology models reliable enough to determine a favorable location? AFAIK, anything can go wrong anywhere.
    - mirimir 10y ago
      Maybe so, but I'm sure that good guesses are possible. Basically, further from the equator, away from oceans, and higher altitude. And away from large cities. I wonder about some of those "useless" Chinese cities, for example.
      - mrec 10y ago
        > I wonder about some of those "useless" Chinese cities, for example. Never attribute to forethought that which is adequately explained by stupidity.
      - flukus 10y ago
        Most of those "useless" chinese cities are filling up now. All of those stories were like looking at a brand new housing estate before any of the houses were on sale.
  - omegaworks 10y ago
    Siberia stands to become more arable if the permafrost thaws. It certainly becomes more drillable. Wonder who might be involved there... https://www.2b1stconsulting.com/exxonmobil-and-rosneft-set-joint-venture-for-western-siberia-tight-oil/ https://www.2b1stconsulting.com/exxonmobil-and-rosneft-set-j...
mirimir 10y ago
Yeah, exponentials are tricky. By the time danger is clear, it's too late to do anything about it. But hey, at least this will probably be self-limiting. Disruption will arguably reduce population and industrialization, and so CO2 emissions will drop.
- cafebabbe 10y ago
  And then good luck rebuilding civilization now that every easily accessible resource has been mined/harvested out.
  - clydethefrog 10y ago
    Let's hope the beings that will rebuild civilization will learn from our mistakes.
    - TeMPOraL 10y ago
      I don't know about you, but I like human civilisation, so this is not much of a consolation for me.
      - mirimir 10y ago
        Well, but you'll likely be dead, no? And yes, I'm sure that parents fear for their kids. Maybe the AIs will pick up where we left off. They'll be sort of human. Especially if hybrids become popular.
    - mirimir 10y ago
      Well, what did we learn from the Indus Valley folks? Or the Amazon folks? Whatever electronic records survive will probably get recycled long before they're read. And paper doesn't last very long. So arguably they'll just have folktales.
    - SerpentJoe 10y ago
      Nobody is rebuilding anything on this planet, not considering how deep we need to drill/mine at this point to get anything good, and the example will not be useful to anyone who arrives here from elsewhere.
rubber_duck 10y ago
Why focus on "fixing" climate ? Why not just assume it's going to become unstable in close future and start building with that assumption ? Large scale isolated citiy domes. Nutrient synthesis that doesn't rely on climate/agriculture. Environment independent energy generation like micro nuclear reactors. Large scale air filtration and temperature control. As the world becomes more interconnected and developed catastrophic outcomes like super virus/bacteria, large scale nuclear event, etc. become bigger threats to entire world. Why not start building self sufficient and well isolated megacities that can function irregardless of climate change ? It's perfectly possible on 50 year timescale if we don't waste time on shoving our heads in to the ground and hoping everything will stay great if we stop burning stuff.
- gnaritas 10y ago
  If you can't mobilize man to fight climate change, you aren't going to mobilize him to prepare for it either. People are in deep denial about the problem.
  - Razengan 10y ago
    Preserving human knowledge and art [0] won't require mobilizing all of mankind; it could be done by a few individuals and it's kinda already being done by Wikipedia, Wikia, "pirates" etc. [0] https://news.ycombinator.com/item?id=13944410 https://news.ycombinator.com/item?id=13944410
    - gnaritas 10y ago
      True, however, the problem is preserving humans from near extinction, not preserving our knowledge and culture for the few who might survive if we ignore the problem.
      - Razengan 10y ago
        > for the few who might survive It doesn't have to be for our survivors... We could, and I believe we should, do it for the next civilization to come after ours, even if it's a few alien visitors. If for no other reason than to leave a legacy of our short existence against the infinity of this universe.
marcosdumay 10y ago
An engineering solution to CH4 may be much easier than one for CO2. We can buy some time without even sequestration.
yongjik 10y ago
IMHO, even if we end up needing some mega-geoengineering project for our survival, it would still be cheaper if we first stop our CO2 emission and then plan for geoengineering, rather than building something scaled for our current CO2 emission trajectory. Basically, if an oil tanker is leaking oil all over the beach, we should first plug the goddamn hole before talking about (expensive) solutions to clean up the contaminated beach. Doing it the other way just doesn't make sense.
- stevenwoo 10y ago
  I think the problem if we are in you scenario is that 200 people own parts of the oil tanker and the beach is owned by 200 people and not everyone wants to pay for the costs of cleaning up the contamination, and that we have to get permission from the owners of each separate plot of beach and mone from each of the 200 people to pay for the cleanup to make the analogy of people roughly equivalent to countries and our current predicament - one or two powerful, rich people could pay for the whole thing but if they decide they don't believe in cleaning up and letting things be they could mess up things for all 200 by themselves.
- taberiand 10y ago
  If we stop the CO2 generation, do we have enough industry left to perform the mega-geoengineering?
vacri 10y ago
> we don't have a chance in hell, pun intended, of surviving as a species if runaway warming becomes a reality. We'll survive as a species, just not as a civilisation.

by fjabre 10y ago

philipkglass 10y ago

Artificial sulfate aerosols look like they could quickly damp positive feedbacks though of course they're no permanent fix and won't do anything to counteract ocean acidification. There are more permanent fixes possible in theory (large scale accelerated silicate weathering) but their feasibility hinges, IMO, on some rather optimistic assumptions about the future trajectory of robotics. Metaphorically speaking, we now have to consider the planetary equivalent of high-risk, high-cost surgery after mostly ignoring the planetary "stop smoking" advice experts have been giving for more than a generation. Also, any large scale sequestration effort is going to be much harder if emissions continue unabated. We're past the point where prevention alone can stabilize atmospheric CO2 but we're never past the point where further anthropogenic emissions can make the problem even worse.

bufbupa 10y ago
Can you elaborate on the optimistic assumptions in robotics that may enable accelerated silicate weathering? Or could you point me to some readings on the matter?
- philipkglass 10y ago
  A search on Google Scholar for "accelerated silicate weathering" will be more informative than my comment. But here's the shortish version... Naturally occurring silicates of magnesium, calcium, sodium, and potassium are thermodynamically prone to weather to carbonates in ambient conditions, when water absorbs CO2 and passes over rocks. In the case of magnesium and calcium in particular, the weathering leads to stable solids that will not spontaneously release CO2 again. A schematic example with calcium silicate: CO2 + CaSiO3 -> SiO2 + CaCO3 Gaseous carbon dioxide and solid calcium silicate become solid silicon dioxide and calcium carbonate. Silicate weathering has multiple advantages over other carbon dioxide removal/sequestration schemes: • The end state is naturally stable. You don't have to worry about the leakiness of underground containment. • It restores the pH balance of the oceans as well as reducing radiative forcing (warming) effects. • It deals equally well with point and distributed sources of CO2 (coal plants, automobile tailpipes). • It can be located anywhere on Earth. It does not need to be adjacent to CO2 sources. • It does not require concentrated CO2 streams, but works with ambient atmospheric concentrations. Natural silicate weathering reactions dominate Earth's CO2 balance in the very long term. But they are strongly kinetically hindered in nature. After a freshly exposed rock surface has weathered to a depth of a few microns, the cation-depleted "rind" drastically slows the weathering of the remaining interior. Without human intervention, it'll take about 100,000 years for natural silicate weathering to restore the pre-industrial baseline of atmospheric CO2 concentrations. There are different ways to improve the kinetics: • Crush bulk rock to a fine sand texture, so full interior weathering finishes much faster (still takes years-to-decades, but no longer takes geological time scales). • Place crushed rock in near-shore ocean environments where mechanical wave erosion keeps removing rinds. • Place crushed rock in acidic tropical agricultural soils where it weathers faster due to low pH and elevated temperature. This also improves soil quality for growing crops. It's not explicitly included in the scholarly literature, but I say that advanced robotics are necessary because the required scale of intervention is staggering, bigger than any engineering endeavor in history. For example, the Columbia Plateau in the United States contains basalt whose alkali and alkaline earth content could bind about 20% of its own mass in CO2, after complete weathering: https://crustal.usgs.gov/geochemical_reference_standards/basaltbcr2.html https://crustal.usgs.gov/geochemical_reference_standards/bas... To neutralize the CO2 that humans emitted in 2015, about 36 billion tons (https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...), would require mining and pulverizing about 180 billion tons of Columbia Plateau basalt. That's about 60 cubic kilometers. We're in no danger of running out of plateau -- it contains more than 170,000 km^3. As for energy estimates, the Bond Work Index for crushing basalt such that 80% of particles pass a 100 micron screen is in the neighborhood of 17-20 kWh per ton: https://www.911metallurgist.com/blog/table-of-bond-work-index-by-minerals https://www.911metallurgist.com/blog/table-of-bond-work-inde... I'll add a factor of 2 for overhead to estimate the whole process energy expenditure. That would mean that using Columbia Plateau basalt, you'd expend 40 kWh per ton of basalt, about 200 kWh per ton of CO2 removed from the atmosphere. That is, energetically speaking, really good compared to schemes that try to run "combustion-in-reverse" to regenerate hydrocarbons from CO2. It's efficient enough that you could actually use coal fired power to drive the whole process and it would still be a net CO2 sink. But at 200 kWh per ton-CO2-scrubbed, it would take 7.2 billion megawatt hours to neutralize humanity's 2015 CO2 emissions. That's an annualized power of 821 gigawatts -- nearly twice the average electrical power generated in the United States. The scale is so vast that I can only imagine advanced robotic manufacturing, mining, and energy generation being up to the task. However you want to modify my baseline scenario -- smaller projects scattered around the Earth instead of one mega-project, being pickier about processing only the best rocks -- I think that the scale is still daunting. But I think it may still be possible because I see automation advancing a lot in the 21st century if we don't precipitate a civilization-ending crisis first.
  - anon1253 10y ago
    It's not the only option either. Combine that solution on a massive scale with re-forestation and (even though eventually it's CO2 neutral) it might actually make a dent. My go-to model was always: - Plant heliostat molten salt reactors in desert coastal areas [1] - Use generated heat to desalinate water - Use desalinated water to provide irrigation - Plant (potentially GMO'ed) bootstrapping organisms to create a soil (greening) - Plant trees - Rinse repeat. However, your idea makes more sense if the only goal is CO2 scrubbing. But adding the heliostat molten salt reactors in a desert might be quite feasible, they generate tons of heat, which can be translated into energy or simply mechanical force (water pressure)…and there is no shortage of silicates in the desert. [1] http://www.solarreserve.com/en/technology/molten-salt-energy-storage http://www.solarreserve.com/en/technology/molten-salt-energy...
    - philipkglass 10y ago
      Yes, re-forestation or afforestation is another scheme worth considering. It can't scale up to the extent of accelerated silicate weathering but it could reach a scale of gigatons of CO2 per year. And it could produce food, wood products, and desirable living space for humans where once there were deserts with little biomass of any kind. You need to harvest-and-bury wood (as biochar, preferably) pretty regularly if the primary goal is CO2 sequestration; otherwise the steady state is approximately equal to current mature forested areas (which store plenty of carbon in soils but aren't great at continuing to remove more from the air). Accelerated silicate weathering and "greening the deserts" are concepts that work well together, too. Mature fertile soil contains weathered minerals and organic matter. Crushing basalt can speed up the weathering part of producing soil, and provide micronutrients for plants plus a couple of important macros (phosphorus and potassium).
      - SwetDrems 10y ago
        Only tangentially related, but here[0] is a video of the great reforestation program that South Korea undertook after the Korean War. They effectively transformed vast arid landscapes into healthy forests. Shows the power of a nation/people coming together with careful planning, forethought, unity, and grit can literally shape the earth. [0] https://www.youtube.com/watch?v=_3KkN8hvUCI https://www.youtube.com/watch?v=_3KkN8hvUCI

rodgerd 10y ago

> It always amazes me how much people and governments focus on prevention when it comes to climate change If the US government was actually focused on prevention, that would be a huge step up from "denying there's a problem."

mirimir 10y ago
I suspect that the interests driving denial are planning to ride the crash. There are probably developments in favorable locations. Land. Security. Infrastructure. Resources.
- marcosdumay 10y ago
  Does somebody have climatology models reliable enough to determine a favorable location? AFAIK, anything can go wrong anywhere.
  - mirimir 10y ago
    Maybe so, but I'm sure that good guesses are possible. Basically, further from the equator, away from oceans, and higher altitude. And away from large cities. I wonder about some of those "useless" Chinese cities, for example.
    - mrec 10y ago
      > I wonder about some of those "useless" Chinese cities, for example. Never attribute to forethought that which is adequately explained by stupidity.
    - flukus 10y ago
      Most of those "useless" chinese cities are filling up now. All of those stories were like looking at a brand new housing estate before any of the houses were on sale.
- omegaworks 10y ago
  Siberia stands to become more arable if the permafrost thaws. It certainly becomes more drillable. Wonder who might be involved there... https://www.2b1stconsulting.com/exxonmobil-and-rosneft-set-joint-venture-for-western-siberia-tight-oil/ https://www.2b1stconsulting.com/exxonmobil-and-rosneft-set-j...

mirimir 10y ago

Yeah, exponentials are tricky. By the time danger is clear, it's too late to do anything about it. But hey, at least this will probably be self-limiting. Disruption will arguably reduce population and industrialization, and so CO2 emissions will drop.

cafebabbe 10y ago
And then good luck rebuilding civilization now that every easily accessible resource has been mined/harvested out.
- clydethefrog 10y ago
  Let's hope the beings that will rebuild civilization will learn from our mistakes.
  - TeMPOraL 10y ago
    I don't know about you, but I like human civilisation, so this is not much of a consolation for me.
    - mirimir 10y ago
      Well, but you'll likely be dead, no? And yes, I'm sure that parents fear for their kids. Maybe the AIs will pick up where we left off. They'll be sort of human. Especially if hybrids become popular.
  - mirimir 10y ago
    Well, what did we learn from the Indus Valley folks? Or the Amazon folks? Whatever electronic records survive will probably get recycled long before they're read. And paper doesn't last very long. So arguably they'll just have folktales.
  - SerpentJoe 10y ago
    Nobody is rebuilding anything on this planet, not considering how deep we need to drill/mine at this point to get anything good, and the example will not be useful to anyone who arrives here from elsewhere.

rubber_duck 10y ago

Why focus on "fixing" climate ? Why not just assume it's going to become unstable in close future and start building with that assumption ? Large scale isolated citiy domes. Nutrient synthesis that doesn't rely on climate/agriculture. Environment independent energy generation like micro nuclear reactors. Large scale air filtration and temperature control. As the world becomes more interconnected and developed catastrophic outcomes like super virus/bacteria, large scale nuclear event, etc. become bigger threats to entire world. Why not start building self sufficient and well isolated megacities that can function irregardless of climate change ? It's perfectly possible on 50 year timescale if we don't waste time on shoving our heads in to the ground and hoping everything will stay great if we stop burning stuff.

gnaritas 10y ago
If you can't mobilize man to fight climate change, you aren't going to mobilize him to prepare for it either. People are in deep denial about the problem.
- Razengan 10y ago
  Preserving human knowledge and art [0] won't require mobilizing all of mankind; it could be done by a few individuals and it's kinda already being done by Wikipedia, Wikia, "pirates" etc. [0] https://news.ycombinator.com/item?id=13944410 https://news.ycombinator.com/item?id=13944410
  - gnaritas 10y ago
    True, however, the problem is preserving humans from near extinction, not preserving our knowledge and culture for the few who might survive if we ignore the problem.
    - Razengan 10y ago
      > for the few who might survive It doesn't have to be for our survivors... We could, and I believe we should, do it for the next civilization to come after ours, even if it's a few alien visitors. If for no other reason than to leave a legacy of our short existence against the infinity of this universe.

marcosdumay 10y ago

An engineering solution to CH4 may be much easier than one for CO2. We can buy some time without even sequestration.

yongjik 10y ago

IMHO, even if we end up needing some mega-geoengineering project for our survival, it would still be cheaper if we first stop our CO2 emission and then plan for geoengineering, rather than building something scaled for our current CO2 emission trajectory. Basically, if an oil tanker is leaking oil all over the beach, we should first plug the goddamn hole before talking about (expensive) solutions to clean up the contaminated beach. Doing it the other way just doesn't make sense.

stevenwoo 10y ago
I think the problem if we are in you scenario is that 200 people own parts of the oil tanker and the beach is owned by 200 people and not everyone wants to pay for the costs of cleaning up the contamination, and that we have to get permission from the owners of each separate plot of beach and mone from each of the 200 people to pay for the cleanup to make the analogy of people roughly equivalent to countries and our current predicament - one or two powerful, rich people could pay for the whole thing but if they decide they don't believe in cleaning up and letting things be they could mess up things for all 200 by themselves.
taberiand 10y ago
If we stop the CO2 generation, do we have enough industry left to perform the mega-geoengineering?

vacri 10y ago

> we don't have a chance in hell, pun intended, of surviving as a species if runaway warming becomes a reality. We'll survive as a species, just not as a civilisation.