15 ms·

Possibility for strong high-latitude cooling under negative emissions

85 points by rgrieselhuber 5y ago

whiddershins 5y ago
It is so easy to not pay attention to how bad global cooling, and/or co2 reduction curtailing plant growth, could be for the environment and for humans. Global warming and CO2 rise are such difficult problems, and we put so much focus there, it makes me really glad to see some people taking a broad view.
detritus 5y ago
We seem to be so far from a practically-useful level of CO2 removal that this seems like a shrill level of concern. That said, the logic could apply to much quicker solutions that could be distributed globally, such as atmospheric albedo modification or space based solar barriers (the latter being hugely speculative, of course - but I could imagine a few SpaceX starships put to poorly-considered use being able to muster something in a decade or three).
- convolvatron 5y ago
  I think a more important lesson here is that this is not a simple system. its pretty unlikely that we're going to able to calmly walk it back to the state it was in before
  - RC_ITR 5y ago
    The even more wild concept is that the atmosphere’s composition was already changing before human involvement, we just sped up the process by like 1000x. We don’t normatively need the atmosphere to be “natural,” we just need it to be in a state that doesn’t destroy the thousands of years of infrastructure we’ve built.
  - landemva 5y ago
    There were many prior states. In fact, it changes. Vikings had pastures on Greenland until it got cold and they were driven off. Greenland is now covered in snow and ice. Will Greenland return to pastures? Probably at some time.
    - jbotz 5y ago
      The Viking colonies on Greenland were during a relatively warm period, but the difference was rather minor... it's not like now Greenland is covered in snow and ice and then it wasn't, the glaciers weren't any smaller then, they were actually a bit bigger. But during this warm period that lasted a couple of hundred years the summers were a bit longer and probably more sunny. The Viking settlements were in the far South of Greenland, actually further South than their prior home on Iceland, on land that's quite green in Summer today as well (just visit Greenland's official tourism site to see what it looks like). Tundra vegetation is actually excellent pasture, very mineral and protein rich... enough so to have supported lots of the largest mammalian mega-fauna!
    - lifeisstillgood 5y ago
      Is this correct? I thought that Greenland was always a marketing lie, and that the viking's refusal to absorb Inuit style living meant they simply could not become self sustaining and eventually lost the result ships (vaguely remembered BBC podcast as source)
- ttiurani 5y ago
  This is an important study because most (all?) scenarios used by the IPCC depend heavily on these (as of now) wildly optimistic CO2 removal levels, either with BECCS or DACs. In order to hit the "brief and rapidly closing window" we have for effective action, we need to look into lowering material flows and energy use by targeting overconsumption. We simply don't have time to wait for a tech miracle, and – as this study points out – the miracle can have huge downsides.
  - hannob 5y ago
    I have no idea why this comment got downvoted. It points precisely to the point: Many current climate scenarios have already negative emissions "priced in". We absolutely need to have research to better understand what that means, and we should have a plan b if negative emissions at large scales don't work.
    - landemva 5y ago
      I didn't downvote though I noticed this, 'We simply don't have time to wait ...'. Whatever the topic, I mentally ignore posts which shill the NEXT WORST THING EVER.
      - _3u10 5y ago
        Exactly, we have lots of time to wait. Humanity survives pretty much no matter what we do. Most of the waiting scenarios involve a drastic decrease in farmland for the US/Europe and larger gains in Canada / Russia. The planet quite frankly doesn’t care if NY / LA / London lose 6 to 12 Ft of land. Even if no one moved and everyone just stayed there to drown, humanity still goes on. The whole thing mostly fixes itself anyway once population peaks in a few decades. It’s not global warming that kills humanity, it’s our population eventually reaching zero through sub replacement birth rates tho maybe there is a saving grace where once incomes get high enough it rebounds.
        drekk 5y ago
        At what cost does humanity survive? I don't want to become a climate refugee. Even the 1.5C model has millions of climate refugees. People still talk about Miami and Dubai as if they'll be around in a century. I am not so arrogant as to think without humans the planet dies. But maybe unlike most Americans I don't want to sacrifice my grandparents so that people can dine in person at Applebee's, nor do I want to live in a worse, less human-friendly world so that oil executives can make another few decades of profit. We can decarbonize with the technology we have today. We know it will be more expensive economically to wait until it's too late, but it'll be more expensive for taxpayers instead of maybe the companies doing so well they can spend millions on lobbying every year. Farming isn't really the issue, we can eke out 10x the calories by cutting pork/chicken/beef. Wet bulb temperatures (where you can't cool off by sweating and die cooked inside out) are a larger issue. Tons of other cycles that we're fucking with besides carbon, like nitrogen and phosphorus. We're also losing arable land to desertification. I don't even have to get started on our available freshwater reserves. To think humanity will just kinda coast by and that it will all mostly fix itself must be a very nice thought, but it flies in the face of what every single person we pay to study this is saying. And they're not saying humans go extinct.
- go_elmo 5y ago
  Approaches aiming at increasing ocean bio activity, thus carbon capture by providing "ocean desert zones" with nutrients by whirling up ocean floor in those regions seems interesting for that purpose. Still a huge inception into the bio system thus risky.
  - detritus 5y ago
    Ah yes, I'd forgotten about iron-seeding - I was thinking entirely in terms of industrial solutions.
    - galangalalgol 5y ago
      I still think iron fertilization is the best bet, not for co2 removal, but for albedo modification. Keeping equatorial kelp or algae mats alive would prevent lots of energy from entering the system. Those mats have albedo close to snow in the infrared, where water is about as absorptive as it gets.
      - detritus 5y ago
        I wonder if we could somehow use strategic placement of fertilisation to encourage processes that laterally help in cleaning up (/collecting) plastic pollution in oceanic gyres? A girl can dream. - ed: I am fascinated by the idea that otherwise horrid floating plastic pollution can act as centres for bio-accumlation leading to local, floating bio-domains. I guess the real problem is plastic bags and fishing nets, not toothbrushes that happen to float.
    - go_elmo 5y ago
      Ive seen stunning simple / passive water column chimney-effect approaches to do this using lower water levels mixing, no sources though, was german tv (arte station)
- _3u10 5y ago
  That’s largely because we aren’t trying it because most geo-engineering solutions have been made illegal and face significant political opposition from those who are point blank against fossil fuels. (Their opposition agains fossil fuels is second only to opposition to nuclear) Look at the situation in Germany where CO2 emitting Russian oil and gas was preferable by the Greens to zero CO2 nuclear. Net zero CO2 is the ultimate bike shedding issue, because it’s so easy a child could solve it, it devolves into endless bickering.
freddealmeida 5y ago
Quite interesting that this is being published in Nature. I think there are far worse things that need to be removed. But so little is discussed on the affect of the sun moving into a solar minimum. That will have some serious consequences as well.
- SantalBlush 5y ago
  >That will have some serious consequences as well. According to NASA [1], that is false. [1] https://climate.nasa.gov/ask-nasa-climate/2953/there-is-no-impending-mini-ice-age/ https://climate.nasa.gov/ask-nasa-climate/2953/there-is-no-i...
  - hedora 5y ago
    This particular issue has been well understood for at least 30 years. Greenhouse gasses are a first order effect. Solar cycles are second order.
    - wrycoder 5y ago
      The principal greenhouse gas is water vapor, and the effect of solar variation on that is not at all “well understood”.
- imtringued 5y ago
  The sun is moving into a solar minimum for the past decades and temperatures are still rising. Just imagine how much more temperatures would be rising if that wasn't the case.
hedora 5y ago
Tl;dr: Climate change is likely to shut down the Atlantic currents, covering Europe and the US northeast in a glacier. (I saw a PBS special on this part in the 90's. Recent satellite data strongly suggest this is already happening. The last time this happened, Europe went from "too hot" to "glacier" in the under fifty years. If we wait for that to happen, then cool the atmosphere, then it'll make the coming ice age worse in the short term. In other decades-old news, if we don't start capturing CO2 after that, and the predictions about runaway greenhouse gas mechanisms are true, Earth will become like Venus, obliterating life on earth. Am I the only one that learned about this from watching PBS in the 90s? Is there something novel in the paper? It's good to raise awareness of just how f-cked we are, I guess.
- ripper1138 5y ago
  So you feel confident that Europe will be under a glacier in 50 years?
  - hedora 5y ago
    I'm confident we'll get about 50 years warning when/if the current stops. It's currently weakening, and weather is a chaotic system. I'm also confident that the root cause of the crunching noise and vibrations from the front end of my car will eventually lead to a breakdown, but I don't have any idea if it'll happen tomorrow or in a year.
    - ripper1138 5y ago
      I see. Of course the North Atlantic current will change/stop at some point regardless of any actions we take (assuming we don’t have technology to keep it going somehow). But delaying that as long as possible is a noble goal.
      - hedora 5y ago
        There's no reason to think it would shutdown in the absence of human intervention. It's extremely stable. Last time it shut down, it was due to elevated CO2 and temperatures, and the conditions that led to that won't naturally reoccur any time soon.
sgt101 5y ago
In other news: population crisis on Mars.
mrfusion 5y ago
Sorry but I’m all panicked out.
01100011 5y ago
What if we tap sources of energy, like fusion and to some extent(*) fission, which are novel to the normal solar/earth system and release extra heat energy into the atmosphere? Since this study is obviously only relevant in the far future, why not add in likely future technologies to the mix? It seems to me that at some point we could just wrap the earth in shutters(since we're talking far future anyway) or intentionally release greenhouse gasses to servo the planet's temp. * - I believe much of the geothermal heat is actually heat from fission already so I don't know if fission energy changes the balance much.
- throwanem 5y ago
  > I believe much of the geothermal heat is actually heat from fission already On what basis do you believe this?
  - topaz0 5y ago
    This seems to have a good explainer: https://www.psu.edu/news/research/story/probing-question-what-heats-earths-core/ https://www.psu.edu/news/research/story/probing-question-wha...
no-body 5y ago
But aren't we at the end off the small ice age? And is global warming really something we can prevent, or is it part off the normal warming and cooling cycles off the earth? I sometimes wonder if all the effort we do is in vain.
- mostly_harmless 5y ago
  There's a huge difference between warming over a couple tens of thousands of years (natural rate), and warming over a couple of decades (our current trajectory). That difference is the eradication of much of life on earth that is unable to evolve to a new environment. For example, insect numbers worldwide are drastically lower than decades ago, and insects are required for almost all pollination of plants and a key source of food for small animals. The "food chain" collapses if there is no first chain. Even a partial loss of ecodiversity can lead to further problems later. Our efforts are certainly not in vain.
gmuslera 5y ago
Global yearly average temperature keeps increasing because not directly by our emissions, but the excess of CO2 and other GHG (that yes, that was mostly our emissions, mostly adding fossil carbon to the cycle). This way we are going head-first towards dangerous levels of it (that cause extreme weather, trigger positive feedback loops and other not so nice things that you won't want to live through) Keeping our current emissions will keep increasing that excess of CO2 and GHG, getting to some sort of net-zero (not the proposed one in COP26, but one counting with all kind of mankind carbon emissions AND the one emitted by the current already triggered feedback loops) will keep more or less the same amount of GHG in the atmosphere as CO2 lasts there for centuries. The only way to have some hope that things don't keep getting worse is to manage to do negative emissions, and bring GHG down to pre-industrial levels, or even lower, if we want to drop in some way the global temperature average that had been steady rising for many decades, as that extra temperature is fueling positive feedback loops. If there is a shortcut for making that temperature drop, because natural processes like the AMOC or whatever, the better, because we are not fighting for how livable will be a particular region of the world, but the entire world.
melgogo 5y ago
The fact that the global average temperature anomaly is running about 1/3 of where climate models said it should be, is proof in itself that the anthrpogenic component of climate change is not remotely understood. It might be zero or net beneficial for all we currently know. H2O is by far the most significant GHG; compared to it, CO2 is a rounding error.
- wrycoder 5y ago
  > (From the OP) ...in stark contrast to the fact that net zero CO2 emissions are required by around 2050 to meet a 50% chance of keeping the average surface temperature increase to below 1.5 °C These forecasts used to be 4.5C or more. Now the forecasts are 1.5C and yet the IPCC is still pushing hard. It happens that the average tropospheric temperature increase over the last 40 years of satellite measurements is 0.13C per decade, or 1.3C per century if that rate continues.[0] We have still not peaked during this interglacial epoch, but the tropospheric warming appears normal and less than the IPCC target. [0] https://www.drroyspencer.com/2022/03/uah-global-temperature-update-for-february-2022-0-00-deg-c/ https://www.drroyspencer.com/2022/03/uah-global-temperature-...
deleted 5y ago
[deleted]

85 points by rgrieselhuber 5y ago

It is so easy to not pay attention to how bad global cooling, and/or co2 reduction curtailing plant growth, could be for the environment and for humans. Global warming and CO2 rise are such difficult problems, and we put so much focus there, it makes me really glad to see some people taking a broad view.

detritus 5y ago

We seem to be so far from a practically-useful level of CO2 removal that this seems like a shrill level of concern. That said, the logic could apply to much quicker solutions that could be distributed globally, such as atmospheric albedo modification or space based solar barriers (the latter being hugely speculative, of course - but I could imagine a few SpaceX starships put to poorly-considered use being able to muster something in a decade or three).

convolvatron 5y ago
I think a more important lesson here is that this is not a simple system. its pretty unlikely that we're going to able to calmly walk it back to the state it was in before
- RC_ITR 5y ago
  The even more wild concept is that the atmosphere’s composition was already changing before human involvement, we just sped up the process by like 1000x. We don’t normatively need the atmosphere to be “natural,” we just need it to be in a state that doesn’t destroy the thousands of years of infrastructure we’ve built.
- landemva 5y ago
  There were many prior states. In fact, it changes. Vikings had pastures on Greenland until it got cold and they were driven off. Greenland is now covered in snow and ice. Will Greenland return to pastures? Probably at some time.
  - jbotz 5y ago
    The Viking colonies on Greenland were during a relatively warm period, but the difference was rather minor... it's not like now Greenland is covered in snow and ice and then it wasn't, the glaciers weren't any smaller then, they were actually a bit bigger. But during this warm period that lasted a couple of hundred years the summers were a bit longer and probably more sunny. The Viking settlements were in the far South of Greenland, actually further South than their prior home on Iceland, on land that's quite green in Summer today as well (just visit Greenland's official tourism site to see what it looks like). Tundra vegetation is actually excellent pasture, very mineral and protein rich... enough so to have supported lots of the largest mammalian mega-fauna!
  - lifeisstillgood 5y ago
    Is this correct? I thought that Greenland was always a marketing lie, and that the viking's refusal to absorb Inuit style living meant they simply could not become self sustaining and eventually lost the result ships (vaguely remembered BBC podcast as source)
ttiurani 5y ago
This is an important study because most (all?) scenarios used by the IPCC depend heavily on these (as of now) wildly optimistic CO2 removal levels, either with BECCS or DACs. In order to hit the "brief and rapidly closing window" we have for effective action, we need to look into lowering material flows and energy use by targeting overconsumption. We simply don't have time to wait for a tech miracle, and – as this study points out – the miracle can have huge downsides.
- hannob 5y ago
  I have no idea why this comment got downvoted. It points precisely to the point: Many current climate scenarios have already negative emissions "priced in". We absolutely need to have research to better understand what that means, and we should have a plan b if negative emissions at large scales don't work.
  - landemva 5y ago
    I didn't downvote though I noticed this, 'We simply don't have time to wait ...'. Whatever the topic, I mentally ignore posts which shill the NEXT WORST THING EVER.
    - _3u10 5y ago
      Exactly, we have lots of time to wait. Humanity survives pretty much no matter what we do. Most of the waiting scenarios involve a drastic decrease in farmland for the US/Europe and larger gains in Canada / Russia. The planet quite frankly doesn’t care if NY / LA / London lose 6 to 12 Ft of land. Even if no one moved and everyone just stayed there to drown, humanity still goes on. The whole thing mostly fixes itself anyway once population peaks in a few decades. It’s not global warming that kills humanity, it’s our population eventually reaching zero through sub replacement birth rates tho maybe there is a saving grace where once incomes get high enough it rebounds.
      - drekk 5y ago
        At what cost does humanity survive? I don't want to become a climate refugee. Even the 1.5C model has millions of climate refugees. People still talk about Miami and Dubai as if they'll be around in a century. I am not so arrogant as to think without humans the planet dies. But maybe unlike most Americans I don't want to sacrifice my grandparents so that people can dine in person at Applebee's, nor do I want to live in a worse, less human-friendly world so that oil executives can make another few decades of profit. We can decarbonize with the technology we have today. We know it will be more expensive economically to wait until it's too late, but it'll be more expensive for taxpayers instead of maybe the companies doing so well they can spend millions on lobbying every year. Farming isn't really the issue, we can eke out 10x the calories by cutting pork/chicken/beef. Wet bulb temperatures (where you can't cool off by sweating and die cooked inside out) are a larger issue. Tons of other cycles that we're fucking with besides carbon, like nitrogen and phosphorus. We're also losing arable land to desertification. I don't even have to get started on our available freshwater reserves. To think humanity will just kinda coast by and that it will all mostly fix itself must be a very nice thought, but it flies in the face of what every single person we pay to study this is saying. And they're not saying humans go extinct.
go_elmo 5y ago
Approaches aiming at increasing ocean bio activity, thus carbon capture by providing "ocean desert zones" with nutrients by whirling up ocean floor in those regions seems interesting for that purpose. Still a huge inception into the bio system thus risky.
- detritus 5y ago
  Ah yes, I'd forgotten about iron-seeding - I was thinking entirely in terms of industrial solutions.
  - galangalalgol 5y ago
    I still think iron fertilization is the best bet, not for co2 removal, but for albedo modification. Keeping equatorial kelp or algae mats alive would prevent lots of energy from entering the system. Those mats have albedo close to snow in the infrared, where water is about as absorptive as it gets.
    - detritus 5y ago
      I wonder if we could somehow use strategic placement of fertilisation to encourage processes that laterally help in cleaning up (/collecting) plastic pollution in oceanic gyres? A girl can dream. - ed: I am fascinated by the idea that otherwise horrid floating plastic pollution can act as centres for bio-accumlation leading to local, floating bio-domains. I guess the real problem is plastic bags and fishing nets, not toothbrushes that happen to float.
  - go_elmo 5y ago
    Ive seen stunning simple / passive water column chimney-effect approaches to do this using lower water levels mixing, no sources though, was german tv (arte station)
_3u10 5y ago
That’s largely because we aren’t trying it because most geo-engineering solutions have been made illegal and face significant political opposition from those who are point blank against fossil fuels. (Their opposition agains fossil fuels is second only to opposition to nuclear) Look at the situation in Germany where CO2 emitting Russian oil and gas was preferable by the Greens to zero CO2 nuclear. Net zero CO2 is the ultimate bike shedding issue, because it’s so easy a child could solve it, it devolves into endless bickering.

freddealmeida 5y ago

Quite interesting that this is being published in Nature. I think there are far worse things that need to be removed. But so little is discussed on the affect of the sun moving into a solar minimum. That will have some serious consequences as well.

SantalBlush 5y ago
>That will have some serious consequences as well. According to NASA [1], that is false. [1] https://climate.nasa.gov/ask-nasa-climate/2953/there-is-no-impending-mini-ice-age/ https://climate.nasa.gov/ask-nasa-climate/2953/there-is-no-i...
- hedora 5y ago
  This particular issue has been well understood for at least 30 years. Greenhouse gasses are a first order effect. Solar cycles are second order.
  - wrycoder 5y ago
    The principal greenhouse gas is water vapor, and the effect of solar variation on that is not at all “well understood”.
imtringued 5y ago
The sun is moving into a solar minimum for the past decades and temperatures are still rising. Just imagine how much more temperatures would be rising if that wasn't the case.

hedora 5y ago

Tl;dr: Climate change is likely to shut down the Atlantic currents, covering Europe and the US northeast in a glacier. (I saw a PBS special on this part in the 90's. Recent satellite data strongly suggest this is already happening. The last time this happened, Europe went from "too hot" to "glacier" in the under fifty years. If we wait for that to happen, then cool the atmosphere, then it'll make the coming ice age worse in the short term. In other decades-old news, if we don't start capturing CO2 after that, and the predictions about runaway greenhouse gas mechanisms are true, Earth will become like Venus, obliterating life on earth. Am I the only one that learned about this from watching PBS in the 90s? Is there something novel in the paper? It's good to raise awareness of just how f-cked we are, I guess.

ripper1138 5y ago
So you feel confident that Europe will be under a glacier in 50 years?
- hedora 5y ago
  I'm confident we'll get about 50 years warning when/if the current stops. It's currently weakening, and weather is a chaotic system. I'm also confident that the root cause of the crunching noise and vibrations from the front end of my car will eventually lead to a breakdown, but I don't have any idea if it'll happen tomorrow or in a year.
  - ripper1138 5y ago
    I see. Of course the North Atlantic current will change/stop at some point regardless of any actions we take (assuming we don’t have technology to keep it going somehow). But delaying that as long as possible is a noble goal.
    - hedora 5y ago
      There's no reason to think it would shutdown in the absence of human intervention. It's extremely stable. Last time it shut down, it was due to elevated CO2 and temperatures, and the conditions that led to that won't naturally reoccur any time soon.

sgt101 5y ago

In other news: population crisis on Mars.

mrfusion 5y ago

Sorry but I’m all panicked out.

01100011 5y ago

What if we tap sources of energy, like fusion and to some extent(*) fission, which are novel to the normal solar/earth system and release extra heat energy into the atmosphere? Since this study is obviously only relevant in the far future, why not add in likely future technologies to the mix? It seems to me that at some point we could just wrap the earth in shutters(since we're talking far future anyway) or intentionally release greenhouse gasses to servo the planet's temp. * - I believe much of the geothermal heat is actually heat from fission already so I don't know if fission energy changes the balance much.

throwanem 5y ago
> I believe much of the geothermal heat is actually heat from fission already On what basis do you believe this?
- topaz0 5y ago
  This seems to have a good explainer: https://www.psu.edu/news/research/story/probing-question-what-heats-earths-core/ https://www.psu.edu/news/research/story/probing-question-wha...

no-body 5y ago

But aren't we at the end off the small ice age? And is global warming really something we can prevent, or is it part off the normal warming and cooling cycles off the earth? I sometimes wonder if all the effort we do is in vain.

mostly_harmless 5y ago
There's a huge difference between warming over a couple tens of thousands of years (natural rate), and warming over a couple of decades (our current trajectory). That difference is the eradication of much of life on earth that is unable to evolve to a new environment. For example, insect numbers worldwide are drastically lower than decades ago, and insects are required for almost all pollination of plants and a key source of food for small animals. The "food chain" collapses if there is no first chain. Even a partial loss of ecodiversity can lead to further problems later. Our efforts are certainly not in vain.

gmuslera 5y ago

Global yearly average temperature keeps increasing because not directly by our emissions, but the excess of CO2 and other GHG (that yes, that was mostly our emissions, mostly adding fossil carbon to the cycle). This way we are going head-first towards dangerous levels of it (that cause extreme weather, trigger positive feedback loops and other not so nice things that you won't want to live through) Keeping our current emissions will keep increasing that excess of CO2 and GHG, getting to some sort of net-zero (not the proposed one in COP26, but one counting with all kind of mankind carbon emissions AND the one emitted by the current already triggered feedback loops) will keep more or less the same amount of GHG in the atmosphere as CO2 lasts there for centuries. The only way to have some hope that things don't keep getting worse is to manage to do negative emissions, and bring GHG down to pre-industrial levels, or even lower, if we want to drop in some way the global temperature average that had been steady rising for many decades, as that extra temperature is fueling positive feedback loops. If there is a shortcut for making that temperature drop, because natural processes like the AMOC or whatever, the better, because we are not fighting for how livable will be a particular region of the world, but the entire world.

melgogo 5y ago

The fact that the global average temperature anomaly is running about 1/3 of where climate models said it should be, is proof in itself that the anthrpogenic component of climate change is not remotely understood. It might be zero or net beneficial for all we currently know. H2O is by far the most significant GHG; compared to it, CO2 is a rounding error.

wrycoder 5y ago
> (From the OP) ...in stark contrast to the fact that net zero CO2 emissions are required by around 2050 to meet a 50% chance of keeping the average surface temperature increase to below 1.5 °C These forecasts used to be 4.5C or more. Now the forecasts are 1.5C and yet the IPCC is still pushing hard. It happens that the average tropospheric temperature increase over the last 40 years of satellite measurements is 0.13C per decade, or 1.3C per century if that rate continues.[0] We have still not peaked during this interglacial epoch, but the tropospheric warming appears normal and less than the IPCC target. [0] https://www.drroyspencer.com/2022/03/uah-global-temperature-update-for-february-2022-0-00-deg-c/ https://www.drroyspencer.com/2022/03/uah-global-temperature-...

deleted 5y ago

[deleted]