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Really interesting. Makes me think of Daisyworld and the Gaia Hypothesis. Daisyworld is a model Earth covered in black and white daisies, that either absorb or

Really interesting. Makes me think of Daisyworld and the Gaia Hypothesis. Daisyworld is a model Earth covered in black and white daisies, that either absorb or reflect light. In the model, black daisies need less light because they absorb more, increasing the Earth's heat absorption. White daisies absorb less so need more light, but also reflect more light back, increasing the surface albedo of the planet and lowering its ambient temperature. Because of this, there's a feedback loop were even if the sun gets a little hotter or colder, the successful daisy would spread and either warm or cool the Earth in response, effectively acting as a stabilizer. Gaia theory suggests that the world is full of these stabilizing systems. Anyone who ever played SimEarth in the 90s, it was based on this theory and even had a Daisyworld simulation built in. In this case, the paper is suggesting that seaweed grows much faster in response to raised CO2, and then sequesters some of that carbon underwater. One question I have is how sequestered the undersea carbon really is and whether it will have other, unknown effects on the deep see ecosystem.

pjc50 8y ago
We know that there are a number of homeostatic (self-regulating) processes that affect the proportion of CO2 in the atmosphere; if it wasn't homeostatic it would have drifted off to an extreme long ago. The key question is how well and how rapidly these mechanisms can respond to an increase in CO2 levels.
- bumholio 8y ago
  The homeostasis might work in a limited range under which the biological world evolved in the recent past. Exceeding that range could quickly turn to a runaway geological event of rapid climate change, a state transition in a complex and unpredictable system. Take for example the great oxidation event happening 2.5 billion years ago. As oxygen excreting algae began to take over methane producing organisms, oxygen started to build up in the atmosphere - first slowly, as there were lots of stuff to oxidize, like methane and iron. Eventually, these naturals sinks were saturated and oxygen levels reached the critical toxic point for the other species, leading to a runaway die-off where more and more oxygen was released and methane - a strong green house gas - rapidly disappeared from the atmosphere. This shock was so massive it produced the 400 million year Huronian glaciation - a whole planet freeze unlike any since. So I have full faith life on Earth will eventually restore the feedback loops and get the temperatures back in the sweet spot. I have less faith that this will happen soon, or that most species, humans included, can survive such a massive transition event.
  - masklinn 8y ago
    > So I have full faith life on Earth will eventually restore the feedback loops and get the temperatures back in the sweet spot. Or just broadly adapt to the new state of things, historical data suggests that atmospheric CO2 levels did reach ~1000PPM up to the Cretaceous, with complete lack of continental ice sheets and temperate forests at the poles. The current sweet spot is a sweet spot for us and the ecosystems we grew up in as a species, it's not a life-wide sweet spot.
    - qubex 8y ago
      “The Return to Cretaceous World” just doesn’t have the same cinematic draw to it.
      - bumholio 8y ago
        I believe the "Cretaceous Greenhouse" would make quite a good movie, considering the massive inland seas that formed during the period over the continental shelf. The majority of people on Earth would have to move house to higher altitudes. It's mind-boggling to consider that we increased the CO2 levels from 280 to 410 ppm during the industrial age. We went a quarter of the way to the Cretaceous super-greenhouse of 1000 ppm, with most of the change accumulating in recent decades. And we are accelerating. It's hard to see how most complex ecosystems would survive that kind of change in just a century or so, evolution is simply not that rapid. Forget moving house, imagine a world where the only functional natural ecosystems are bacterial.
        deleted 8y ago
        [deleted]
        masklinn 8y ago
        > I believe the "Cretaceous Greenhouse" would make quite a good movie, considering the massive inland seas that formed during the period over the continental shelf. The majority of people on Earth would have to move house to higher altitudes. Many breadbasket lands are also fairly low-lying. The northern china plain is mostly under 50m. Even if it doesn't get covered in water, saline intrusion will seriously hurt it, as it's already starting to hurt countries with extensive coastlines and river deltas like Vietnam or Bangladesh.
- JulianMorrison 8y ago
  Also it may be homeostatic with multiple attractors, push too hard from one and you pop over into the one next door.
- scythe 8y ago
  The big cycle is caused by the reaction of magnesium silicate with carbon dioxide. Mg silicate is the chief component of Earth's mantle. As temperature increases, silicate rocks are worn away faster by rain and wind, and absorb more CO2. This CO2 eventually sinks down into the mantle as magnesium carbonate, where it is very slowly re-released by volcanoes (the majority of Earth's carbon is in the mantle). As CO2 is sequestered, the Earth cools, and the weathering of silicate rocks slows, especially when they are covered by glaciers. Then the release of CO2 by volcanoes starts to outpace the absorption by olivine, and the atmosphere warms up again. Eventually as the Sun gets brighter, the equilibrium amount of CO2 in the atmosphere is expected to drop below the requirements for plant life, and the Earth will die. By heating the atmosphere, we hasten the arrival of the next glacial cycle, but we are (thankfully) at low risk of starving the biosphere.
wklauss 8y ago
> Because of this, there's a feedback loop were even if the sun gets a little hotter or colder, the successful daisy would spread and either warm or cool the Earth in response, effectively acting as a stabilizer. Gaia theory suggests that the world is full of these stabilizing systems. There are several mechanisms in place on earth to stabilize changes in atmospheric composition and temperature (otherwise an sporadic eruption of a volcano or glacial eras would have thrown things out of whack long time ago). I don't think this is an hypothesis. We have seen some of them in action in recent years, like the advanced rate of reforestation due to larger levels of CO2 in the atmosphere. The problem is we don't know what would happen if we push these to the limit or what their limit really is. And they are very complex in the way the interact. For example. Warmer oceans and larger levels of CO2 will make phytoplankton grow faster, absorbing more CO2 in return, but it will also accelerate the growth of zooplankton, that feeds on it. This creates a bottleneck. So TL;DR: yeah, it's cool we have these mechanisms around but the goal should still be to keep things as close to the baseline as possible (and we have been really bad about it in the last century)
- zerealshadowban 8y ago
  What specific baseline do you pick, and why? are there multiple variables involved in that "baseline"? have these variables changed over the 10k years preceding the Industrial Revolution? together or separately? what about these same variables over the last 200k years?
  - snikeris 8y ago
    Good questions. You also have to consider the variables that have changed since the Industrial Revolution. There are more people on earth to feed and provide a modern standard of living. We should work to reduce the costs on the planet for these things, but we can't eschew the progress we've made in order to return to some arbitrary baseline. See: ecomodernism
    - zerealshadowban 8y ago
      Yes, one would most likely have followup questions once the baseline and its variables are made explicit.
matt42 8y ago
>> Gaia theory suggests that the world is full of these stabilizing systems. Earth may have tricks to save its ecosystem, one of them could be temporarily increase temperatures and sea levels, just enough to end humanity.
- swarnie_ 8y ago
  The Great Filter in effect.
- jules 8y ago
  It is exceedingly unlikely that raised temperatures or sea levels would end humanity. Even if all ice melts there would still be a lot of land, and humans can and do currently survive in hot climates. The habitable zone will just shrink a bit, but it will also expand in other places. Siberia + 5 degrees is still cold.
  - enraged_camel 8y ago
    No, this is very wrong. It’s not about having land to live on and being able to continue to breathe on it. Of course we would be able to do that. The issue is all the parts of the ecosystem we have come to rely on. Animals, plants, insects... the entire global economy and our ways of live are tightly intertwined with everything else and even small disruptions can have enormous repercussions, especially on more vulnerable populations in the world.
    - mbostleman 8y ago
      This description is full of hyperbolic generalities. The available land example may or may not be comprehensive, but at least it's specific. I think the biggest problem that I have about everything climate change / global warming is that we are making laws to force (don't forget that force means pointing guns at people regardless of the warm and fuzzy intentions used to sell it) entire populations and their economies in the absence of so much specific knowledge. That doesn't make me a denier because accept / deny is not really the issue. Just because I accept the general premise doesn't mean that I trust the depth of the understanding to the point that I am willing to turn a gun on my neighbor to either reduce their liberty and / or confiscate their personal property in the name of said premise.
drubio 8y ago
> In this case, the paper is suggesting that seaweed grows much faster in response to raised CO2, and then sequesters some of that carbon underwater. Makes you wonder about news like this seaweed deluge in the Caribbean and how it's related to an increase in CO2 "In 2011 it was the first time we'd seen it...says Professor Hazel Oxenford, an expert in fisheries biology and management at the University of the West Indies...It came as a complete shock and no-one had a clue what to do with it." "For us, the worst year we had for sargassum still remains 2015'..says Carla Daniel of Barbados Sea Turtle Project" "Now it is happening again and everything suggests 2018 could be the worst year yet." https://www.bbc.co.uk/news/world-latin-america-45044513 https://www.bbc.co.uk/news/world-latin-america-45044513 https://www.riviera-maya-news.com/first-seaweed-barrier-to-be-placed-in-cancun-waters-this-week/2018.html https://www.riviera-maya-news.com/first-seaweed-barrier-to-b...
JumpCrisscross 8y ago
> Gaia theory suggests that the world is full of these stabilizing systems Doesn’t it go considerably further, into almost suggesting the Earth is a spiritual or conscious entity?
- ghostbrainalpha 8y ago
  https://en.wikipedia.org/wiki/Gaia_hypothesis https://en.wikipedia.org/wiki/Gaia_hypothesis No. If it did, then it wouldn't be a theory, it would just be a religious belief. Although, I would agree that many of the people working on the theory, would privately believe something like that.
azernik 8y ago
This is actually not at all what the paper is saying. It's saying that a natural carbon-sequestration process we already knew about is more effective than we thought. It says nothing about the way seaweed growth changes with increased carbon levels.
- benza 8y ago
  Hy
- mistercow 8y ago
  In other words, it sounds like the above commenter is suggesting that seaweed might unexpectedly save us. But the actual point is almost the opposite: this means we’ve been relying on something all along that we didn’t know we needed to protect.
  - azernik 8y ago
    I hadn't thought about it that way! Although I'm actually not sure in which direction it changes their priors - I'm not sure if this adds to the negative-carbon side of the scales in models taking this into account, or if this was already factored into some kind of separate measurement of total natural carbon sequestration and so the loss of seaweed now adds a bigger positive-carbon term.
red75prime 8y ago
> Gaia theory suggests that the world is full of these stabilizing systems. Or stable feedback loops exist longer (because they are stable) and that's all there is to it. Life managed to almost kill itself a couple of times during Huronian glaciation.
kokey 8y ago
Also reminds me of Richard Lindzen's Iris hypothesis, which suggest that temperature increases in the tropics will reduce cirrus clouds and thus let more heat escape from the atmosphere. Lindzen and his theories are controversial, but I do think there may not have been enough focus on possible negative feedback mechanisms like this.
- bjourne 8y ago
  But that would also mean that much more sunlight would hit the surface of the earth and not be reflected by those clouds.
dwc 8y ago
> One question I have is how sequestered the undersea carbon really is Depends on how you interpret "sequestered". In the sense that it's locked away somewhere for a long time, like organic matter frozen into tundra, it's not very sequestered. But as long as there's lots of seaweed there'll be a lot of carbon taken up. Even though individual plants may die and release their carbon on a relatively short timeline, new growth will take up carbon.

pjc50 8y ago

We know that there are a number of homeostatic (self-regulating) processes that affect the proportion of CO2 in the atmosphere; if it wasn't homeostatic it would have drifted off to an extreme long ago. The key question is how well and how rapidly these mechanisms can respond to an increase in CO2 levels.

bumholio 8y ago
The homeostasis might work in a limited range under which the biological world evolved in the recent past. Exceeding that range could quickly turn to a runaway geological event of rapid climate change, a state transition in a complex and unpredictable system. Take for example the great oxidation event happening 2.5 billion years ago. As oxygen excreting algae began to take over methane producing organisms, oxygen started to build up in the atmosphere - first slowly, as there were lots of stuff to oxidize, like methane and iron. Eventually, these naturals sinks were saturated and oxygen levels reached the critical toxic point for the other species, leading to a runaway die-off where more and more oxygen was released and methane - a strong green house gas - rapidly disappeared from the atmosphere. This shock was so massive it produced the 400 million year Huronian glaciation - a whole planet freeze unlike any since. So I have full faith life on Earth will eventually restore the feedback loops and get the temperatures back in the sweet spot. I have less faith that this will happen soon, or that most species, humans included, can survive such a massive transition event.
- masklinn 8y ago
  > So I have full faith life on Earth will eventually restore the feedback loops and get the temperatures back in the sweet spot. Or just broadly adapt to the new state of things, historical data suggests that atmospheric CO2 levels did reach ~1000PPM up to the Cretaceous, with complete lack of continental ice sheets and temperate forests at the poles. The current sweet spot is a sweet spot for us and the ecosystems we grew up in as a species, it's not a life-wide sweet spot.
  - qubex 8y ago
    “The Return to Cretaceous World” just doesn’t have the same cinematic draw to it.
    - bumholio 8y ago
      I believe the "Cretaceous Greenhouse" would make quite a good movie, considering the massive inland seas that formed during the period over the continental shelf. The majority of people on Earth would have to move house to higher altitudes. It's mind-boggling to consider that we increased the CO2 levels from 280 to 410 ppm during the industrial age. We went a quarter of the way to the Cretaceous super-greenhouse of 1000 ppm, with most of the change accumulating in recent decades. And we are accelerating. It's hard to see how most complex ecosystems would survive that kind of change in just a century or so, evolution is simply not that rapid. Forget moving house, imagine a world where the only functional natural ecosystems are bacterial.
      - deleted 8y ago
        [deleted]
      - masklinn 8y ago
        > I believe the "Cretaceous Greenhouse" would make quite a good movie, considering the massive inland seas that formed during the period over the continental shelf. The majority of people on Earth would have to move house to higher altitudes. Many breadbasket lands are also fairly low-lying. The northern china plain is mostly under 50m. Even if it doesn't get covered in water, saline intrusion will seriously hurt it, as it's already starting to hurt countries with extensive coastlines and river deltas like Vietnam or Bangladesh.
JulianMorrison 8y ago
Also it may be homeostatic with multiple attractors, push too hard from one and you pop over into the one next door.
scythe 8y ago
The big cycle is caused by the reaction of magnesium silicate with carbon dioxide. Mg silicate is the chief component of Earth's mantle. As temperature increases, silicate rocks are worn away faster by rain and wind, and absorb more CO2. This CO2 eventually sinks down into the mantle as magnesium carbonate, where it is very slowly re-released by volcanoes (the majority of Earth's carbon is in the mantle). As CO2 is sequestered, the Earth cools, and the weathering of silicate rocks slows, especially when they are covered by glaciers. Then the release of CO2 by volcanoes starts to outpace the absorption by olivine, and the atmosphere warms up again. Eventually as the Sun gets brighter, the equilibrium amount of CO2 in the atmosphere is expected to drop below the requirements for plant life, and the Earth will die. By heating the atmosphere, we hasten the arrival of the next glacial cycle, but we are (thankfully) at low risk of starving the biosphere.

wklauss 8y ago

> Because of this, there's a feedback loop were even if the sun gets a little hotter or colder, the successful daisy would spread and either warm or cool the Earth in response, effectively acting as a stabilizer. Gaia theory suggests that the world is full of these stabilizing systems. There are several mechanisms in place on earth to stabilize changes in atmospheric composition and temperature (otherwise an sporadic eruption of a volcano or glacial eras would have thrown things out of whack long time ago). I don't think this is an hypothesis. We have seen some of them in action in recent years, like the advanced rate of reforestation due to larger levels of CO2 in the atmosphere. The problem is we don't know what would happen if we push these to the limit or what their limit really is. And they are very complex in the way the interact. For example. Warmer oceans and larger levels of CO2 will make phytoplankton grow faster, absorbing more CO2 in return, but it will also accelerate the growth of zooplankton, that feeds on it. This creates a bottleneck. So TL;DR: yeah, it's cool we have these mechanisms around but the goal should still be to keep things as close to the baseline as possible (and we have been really bad about it in the last century)

zerealshadowban 8y ago
What specific baseline do you pick, and why? are there multiple variables involved in that "baseline"? have these variables changed over the 10k years preceding the Industrial Revolution? together or separately? what about these same variables over the last 200k years?
- snikeris 8y ago
  Good questions. You also have to consider the variables that have changed since the Industrial Revolution. There are more people on earth to feed and provide a modern standard of living. We should work to reduce the costs on the planet for these things, but we can't eschew the progress we've made in order to return to some arbitrary baseline. See: ecomodernism
  - zerealshadowban 8y ago
    Yes, one would most likely have followup questions once the baseline and its variables are made explicit.

matt42 8y ago

>> Gaia theory suggests that the world is full of these stabilizing systems. Earth may have tricks to save its ecosystem, one of them could be temporarily increase temperatures and sea levels, just enough to end humanity.

swarnie_ 8y ago
The Great Filter in effect.
jules 8y ago
It is exceedingly unlikely that raised temperatures or sea levels would end humanity. Even if all ice melts there would still be a lot of land, and humans can and do currently survive in hot climates. The habitable zone will just shrink a bit, but it will also expand in other places. Siberia + 5 degrees is still cold.
- enraged_camel 8y ago
  No, this is very wrong. It’s not about having land to live on and being able to continue to breathe on it. Of course we would be able to do that. The issue is all the parts of the ecosystem we have come to rely on. Animals, plants, insects... the entire global economy and our ways of live are tightly intertwined with everything else and even small disruptions can have enormous repercussions, especially on more vulnerable populations in the world.
  - mbostleman 8y ago
    This description is full of hyperbolic generalities. The available land example may or may not be comprehensive, but at least it's specific. I think the biggest problem that I have about everything climate change / global warming is that we are making laws to force (don't forget that force means pointing guns at people regardless of the warm and fuzzy intentions used to sell it) entire populations and their economies in the absence of so much specific knowledge. That doesn't make me a denier because accept / deny is not really the issue. Just because I accept the general premise doesn't mean that I trust the depth of the understanding to the point that I am willing to turn a gun on my neighbor to either reduce their liberty and / or confiscate their personal property in the name of said premise.

drubio 8y ago

> In this case, the paper is suggesting that seaweed grows much faster in response to raised CO2, and then sequesters some of that carbon underwater. Makes you wonder about news like this seaweed deluge in the Caribbean and how it's related to an increase in CO2 "In 2011 it was the first time we'd seen it...says Professor Hazel Oxenford, an expert in fisheries biology and management at the University of the West Indies...It came as a complete shock and no-one had a clue what to do with it." "For us, the worst year we had for sargassum still remains 2015'..says Carla Daniel of Barbados Sea Turtle Project" "Now it is happening again and everything suggests 2018 could be the worst year yet." https://www.bbc.co.uk/news/world-latin-america-45044513 https://www.bbc.co.uk/news/world-latin-america-45044513 https://www.riviera-maya-news.com/first-seaweed-barrier-to-be-placed-in-cancun-waters-this-week/2018.html https://www.riviera-maya-news.com/first-seaweed-barrier-to-b...

JumpCrisscross 8y ago

> Gaia theory suggests that the world is full of these stabilizing systems Doesn’t it go considerably further, into almost suggesting the Earth is a spiritual or conscious entity?

ghostbrainalpha 8y ago
https://en.wikipedia.org/wiki/Gaia_hypothesis https://en.wikipedia.org/wiki/Gaia_hypothesis No. If it did, then it wouldn't be a theory, it would just be a religious belief. Although, I would agree that many of the people working on the theory, would privately believe something like that.

azernik 8y ago

This is actually not at all what the paper is saying. It's saying that a natural carbon-sequestration process we already knew about is more effective than we thought. It says nothing about the way seaweed growth changes with increased carbon levels.

benza 8y ago
Hy
mistercow 8y ago
In other words, it sounds like the above commenter is suggesting that seaweed might unexpectedly save us. But the actual point is almost the opposite: this means we’ve been relying on something all along that we didn’t know we needed to protect.
- azernik 8y ago
  I hadn't thought about it that way! Although I'm actually not sure in which direction it changes their priors - I'm not sure if this adds to the negative-carbon side of the scales in models taking this into account, or if this was already factored into some kind of separate measurement of total natural carbon sequestration and so the loss of seaweed now adds a bigger positive-carbon term.

red75prime 8y ago

> Gaia theory suggests that the world is full of these stabilizing systems. Or stable feedback loops exist longer (because they are stable) and that's all there is to it. Life managed to almost kill itself a couple of times during Huronian glaciation.

kokey 8y ago

Also reminds me of Richard Lindzen's Iris hypothesis, which suggest that temperature increases in the tropics will reduce cirrus clouds and thus let more heat escape from the atmosphere. Lindzen and his theories are controversial, but I do think there may not have been enough focus on possible negative feedback mechanisms like this.

bjourne 8y ago
But that would also mean that much more sunlight would hit the surface of the earth and not be reflected by those clouds.

dwc 8y ago

> One question I have is how sequestered the undersea carbon really is Depends on how you interpret "sequestered". In the sense that it's locked away somewhere for a long time, like organic matter frozen into tundra, it's not very sequestered. But as long as there's lots of seaweed there'll be a lot of carbon taken up. Even though individual plants may die and release their carbon on a relatively short timeline, new growth will take up carbon.