5 ms·

Climate Predictions: Worst-Case May Be Most Accurate, Study Finds

36 points by brianchu 14y ago

rayiner 14y ago
I feel like when we see estimates of 2-5C warmer global temperatures, people fail to appreciate how monumentally dramatic the difference is. For reference, during the last ice age, global temperatures were 5C colder than today. At that time, Chicago was under two miles of ice.
- rdl 14y ago
  At some point, if this becomes clearly inevitable, I'm hoping large-scale geoengineering happens. It would be awesome to be able to personally finance it, and from what I've seen, it would be in the hundreds of millions of dollars, so a bunch of families could individually, or even a kickstarter circa 2025.
  - rayiner 14y ago
    What do you mean by "geoengineering" in this specific context?
    - maratd 14y ago
      With about 100 mil worth of cash on an annual basis, you can pump enough sulfur into the stratosphere to cool the planet and keep the temps stable. It's pretty straightforward and a proven method (think volcano eruptions).
      - rdl 14y ago
        Just spraying seawater into the air (from ships) would increase albedo (white clouds reflect much more incoming radiation than black seas), lowering temperature, in a pretty benign way. There's also iron seeding (to make algae). Bill Gates is funding it. I still think his work on Polio eradication is more valuable, but this is pretty awesome too.
        vlad_t 14y ago
        Spraying seawater also impacts in another way - produces a lot of aerosol (salt particles, and so on) which contributes a lot into pollution.
      - rdl 14y ago
        Also, the exciting thing about geoengineering is you don't really have to ask anyone's permission. If you had a random country flagged ship and a bunch of SO2, you could pretty much just do this thing without telling anyone. They would presumably see it from satellites after atmospheric sampling (and people with eyes in the evening) noticed, but I'm unclear what the legal process would be to stop it.
  - AJ007 14y ago
    In The Vanishing Face of Gaia James Lovelock theorizes that geoengineering would trigger a cascading effect of problems, much like a a sick patient on an ever increasing regimen of prescription medications, each solving one problem while causing three. While other portions of the book are questionable, I tend to agree with this analogy. The best case would be for the environment to re-balance itself -- of course, human cause or not, our environment is not static and is destined to continual change. Unfortunately James Lovelock's worst case scenario is an earth which is capable of producing enough food to support single digit percentages of the world's current population. That is a pretty brutal death sentence for the current state of human civilization.
    - rdl 14y ago
      There are changes humans make to the environment which do make it better (at least for humans) -- building dams on rivers which otherwise flood periodically, culling wood and undergrowth to keep large-scale forest fires from happening, etc. There are environmental costs to each of those, but the benefits (direct and economic) far outweigh them, and stuff like salmon ladders, helicopter transport, etc. can deal with some of the harm. The best long-term outcome for humanity is to use capitalism and science/technology to generate as much wealth as possible AND do as little damage to the environment as possible, but I think the "have a much lighter footprint and generate less wealth" option is off the table -- it's not going to be acceptable to generate less wealth than we have now, so really the most favorable outcome is to try to scale the wealth generation up faster than the harm done, and then use some wealth to ameliorate specific severe problems.
      - oelewapperke 14y ago
        I don't think you can have it both ways. Either we can predict the effect of things on the environment (co2, and other things we could use for geoengineering), or we cannot. If you believe we cannot predict and prevent cascading problems or adapt to them then you're the same thing as a climate change denier, since who's to say that we got the cascading effect of co2 increase right ? If you believe we can predict those consequences, then geoengineering will allow the human race to take control of the climate. So the problem of climate change becomes the problem of finding the set of consequences we like best. Climate change becomes a problem similar to animals digging holes in a dam : an inconvenience to be monitored, but nothing more. This ignores political problems of course. Geoengineering would make one hell of a weapon of war, for example. China, given it's coastline, might choose to raise the sea level by 5 meters with little consequence for them, but major US population centers would become unliveable (New York, San Francisco), as would many European cities. Geoengineering, used like that, can do far more damage than 5000 nukes could.
- giardini 14y ago
  Chicago's temperature can vary 5C in a single day. Does that mean it will suddenly be sheeted with two miles of ice?
  - rayiner 14y ago
    What on earth gets you from point A to point B here...
  - rdl 14y ago
    Shifting the baseline of average temperature does make a huge difference in extreme outliers (hurricanes, etc.). Similarly, raising the average IQ of a site increases the number of patio11. It also makes a difference if there's a seasonal change -- like, right now, all of the ice melts in the summer at the southern extent of an ice sheet, but if the temperature drops a critical amount, the ice lasts all summer, and starts to accumulate. Or temperature rises and the reverse happens.
- Zarkonnen 14y ago
  Yeah. The problem here isn't really whether we have to turn up the aircon in the summer. The problem is agriculture. Right now, when there's a particularly hot summer, you get (at least here in Switzerland) lots of news stories about poor very poor harvests due to the heat. With a 2-5C increase, nearly all summers will be particularly hot, and nearly all harvests will be particularly poor. And we simply will not have enough food in the world.
droithomme 14y ago
I like the part where they say that actual observed data is unreliable so they'll use a made up model instead to prove their claims. > "Satellite observations of clouds are sketchy, and contain errors."
- dmlorenzetti 14y ago
  they say that actual observed data is unreliable so they'll use a made up model instead to prove their claims. A better paraphrase would be "they say that accurate data on one part of the system are hard to get, so they compared several models using another, correlated, part of the system, for which better data are readily available." Also, since their claims relate to which of 16 models match "actual observed data" best, it's incorrect to characterize their work as using a model to prove their claims. The models are the subject of their claims, not tools used to prove them.
- justsee 14y ago
  I think you're misrepresenting the facts with your response, as the article actually states they decided to use humidity data rather than satellite data of clouds, because "conveniently, high-quality relative humidity data is readily available from satellites". I'm not sure how you can determine whether their approach is good or bad from that article.
- jws 14y ago
  You mean the part where they built their model off the accurately measurable water vapor content instead of building it off of the ambiguous reflectivity? [Edit: ok, let's not all pile on.]
  - deleted 14y ago
    [deleted]
- guscost 14y ago
  Looks like the climate police don't appreciate your objection. Figures.
drivebyacct2 14y ago
I swear there is a common denominator between the dissonance that allows people to find any tiny thing they can to confirm their beliefs even the in the face of growing and yet already insurmountable evidence. For years climate change skeptics held on to one or two prominent scientists who disagreed. They've both recanted and apologized and urged a reexamination of the science, yet doubters just latched onto something else. Or, in the case of droithomme, find some half-invented ad hominem attack to use to dismiss the ENTIRE body of science on the issue. It's the same people that swore to me, up and down, bet me and made foolish statements that Romney was going to have some magic emotional boost and that Nate Silver was the devil working for the liberals and that his numbers were "wrong". That you don't like the facts or that they don't fit with your world view does nothing to make them any less true.
- inthewoods 14y ago
  They seem to be following a familiar pattern: - First, deny that temps are rising. - Next, admit they are rising, but that it isn't caused by humans. - Next (and perhaps finally), admit they rising, and that it is caused by humans, but state that there's nothing that can be done about it anyway.
- guscost 14y ago
  You seem to be fond of exaggeration.
  - drivebyacct2 14y ago
    Oh! No wonder you're trolling me. After a glance at your comments, I accidentally nailed you spot on for both global warming and Nate Silver without even realizing your last page of comments is denial of both! I don't know why you're calling me names. I made a single comment that had to do with the actual issue of global warming and now that's grounds for me being a climate change zealot? I'll ask you again, do you realize that dismissing science as zealotry with no actual evidence or argument makes your position look less legitimate?
    - 14y ago
guscost 14y ago
I don't trust this study, because I don't trust National Geographic with regard to this issue. Go ahead and shame the disbeliever, I'm used to it.
- drivebyacct2 14y ago
  You know, when you come by, write a controversial one-line dismissal of an article, mock anyone who might disagree or even just wonder why you feel that way, and offer NO explanation or reasoning.... that is called trolling. The name-calling and accusations elsewhere are just further evidence.
- deleted 14y ago
  [deleted]
waterlesscloud 14y ago
I'm always cautious of the models as you get to the more extreme cases. To me it seems likely that as you get further and further from the current state that there are unknown factors lurking somewhere. Those factors may represent positive feedback, they may be negative feedback, or they may not exist at all. But to me the further into the unknown we go, the further into the unknown we are, if that makes sense. To be absolutely clear, I think the models probably work well enough for the near range. It's the far ranges I wonder about.
patrickgzill 14y ago
We were told back in the late 1980s and early 1990s that huge computer models were written, that ran on supercomputers, to model and predict climate change. The fastest Cray in 1990 could do (I think) 60 GFlops when loaded with 32 processors, which is roughly the sustained GFlops as a high end i7. So clearly it is not a case of "just need a faster supercomputer and we will have an accurate prediction". Reality is, from what I can tell, is that we don't have an accurate mathematical model of all the pieces that go into global climate to run on a supercomputer, no matter how powerful.
- guscost 14y ago
  Bingo.
- oscilloscope 14y ago
  We don't even have a particularly good data model. If you're interested in the water cycle, you'll have to construct that data from dozens of agencies in hundreds of governments. If the data was collected, linked together and published in an accessible form, more people could experiment with statistics, machine learning and visualization. Right now the data is in labyrinthine web forms, SOAP services, XLS files, GIS systems, etc. The barrier to entry needs to be lower.
- macavity23 14y ago
  Agreed. And even then, the system you're dealing with is so 'chaotic' (i.e. massive effects can be caused by very small changes in data) that you get diminishing returns the more data you have. Take the weather forecast as a (very) slimmed-down version of this problem. Yes, weather forecasts are better now than they were 20 years ago, but how much better? In the UK now, the 24h forecast is pretty accurate most of the time, but the three-day is very iffy, and a week out is still a crap shoot. That's despite a metric fuckton of satellite data and some serious hardware (the UK met office numbercruncher consumes more than a megawatt!). We're always going to be making guesses here. It seems, to my non-climatologist brain anyway, that the most up-to-date models produce predictions that are fairly consistent with the real world data we have. I would say the political and economic problems are much more important, and harder to solve.

36 points by brianchu 14y ago

I feel like when we see estimates of 2-5C warmer global temperatures, people fail to appreciate how monumentally dramatic the difference is. For reference, during the last ice age, global temperatures were 5C colder than today. At that time, Chicago was under two miles of ice.

rdl 14y ago
At some point, if this becomes clearly inevitable, I'm hoping large-scale geoengineering happens. It would be awesome to be able to personally finance it, and from what I've seen, it would be in the hundreds of millions of dollars, so a bunch of families could individually, or even a kickstarter circa 2025.
- rayiner 14y ago
  What do you mean by "geoengineering" in this specific context?
  - maratd 14y ago
    With about 100 mil worth of cash on an annual basis, you can pump enough sulfur into the stratosphere to cool the planet and keep the temps stable. It's pretty straightforward and a proven method (think volcano eruptions).
    - rdl 14y ago
      Just spraying seawater into the air (from ships) would increase albedo (white clouds reflect much more incoming radiation than black seas), lowering temperature, in a pretty benign way. There's also iron seeding (to make algae). Bill Gates is funding it. I still think his work on Polio eradication is more valuable, but this is pretty awesome too.
      - vlad_t 14y ago
        Spraying seawater also impacts in another way - produces a lot of aerosol (salt particles, and so on) which contributes a lot into pollution.
    - rdl 14y ago
      Also, the exciting thing about geoengineering is you don't really have to ask anyone's permission. If you had a random country flagged ship and a bunch of SO2, you could pretty much just do this thing without telling anyone. They would presumably see it from satellites after atmospheric sampling (and people with eyes in the evening) noticed, but I'm unclear what the legal process would be to stop it.
- AJ007 14y ago
  In The Vanishing Face of Gaia James Lovelock theorizes that geoengineering would trigger a cascading effect of problems, much like a a sick patient on an ever increasing regimen of prescription medications, each solving one problem while causing three. While other portions of the book are questionable, I tend to agree with this analogy. The best case would be for the environment to re-balance itself -- of course, human cause or not, our environment is not static and is destined to continual change. Unfortunately James Lovelock's worst case scenario is an earth which is capable of producing enough food to support single digit percentages of the world's current population. That is a pretty brutal death sentence for the current state of human civilization.
  - rdl 14y ago
    There are changes humans make to the environment which do make it better (at least for humans) -- building dams on rivers which otherwise flood periodically, culling wood and undergrowth to keep large-scale forest fires from happening, etc. There are environmental costs to each of those, but the benefits (direct and economic) far outweigh them, and stuff like salmon ladders, helicopter transport, etc. can deal with some of the harm. The best long-term outcome for humanity is to use capitalism and science/technology to generate as much wealth as possible AND do as little damage to the environment as possible, but I think the "have a much lighter footprint and generate less wealth" option is off the table -- it's not going to be acceptable to generate less wealth than we have now, so really the most favorable outcome is to try to scale the wealth generation up faster than the harm done, and then use some wealth to ameliorate specific severe problems.
    - oelewapperke 14y ago
      I don't think you can have it both ways. Either we can predict the effect of things on the environment (co2, and other things we could use for geoengineering), or we cannot. If you believe we cannot predict and prevent cascading problems or adapt to them then you're the same thing as a climate change denier, since who's to say that we got the cascading effect of co2 increase right ? If you believe we can predict those consequences, then geoengineering will allow the human race to take control of the climate. So the problem of climate change becomes the problem of finding the set of consequences we like best. Climate change becomes a problem similar to animals digging holes in a dam : an inconvenience to be monitored, but nothing more. This ignores political problems of course. Geoengineering would make one hell of a weapon of war, for example. China, given it's coastline, might choose to raise the sea level by 5 meters with little consequence for them, but major US population centers would become unliveable (New York, San Francisco), as would many European cities. Geoengineering, used like that, can do far more damage than 5000 nukes could.
giardini 14y ago
Chicago's temperature can vary 5C in a single day. Does that mean it will suddenly be sheeted with two miles of ice?
- rayiner 14y ago
  What on earth gets you from point A to point B here...
- rdl 14y ago
  Shifting the baseline of average temperature does make a huge difference in extreme outliers (hurricanes, etc.). Similarly, raising the average IQ of a site increases the number of patio11. It also makes a difference if there's a seasonal change -- like, right now, all of the ice melts in the summer at the southern extent of an ice sheet, but if the temperature drops a critical amount, the ice lasts all summer, and starts to accumulate. Or temperature rises and the reverse happens.
Zarkonnen 14y ago
Yeah. The problem here isn't really whether we have to turn up the aircon in the summer. The problem is agriculture. Right now, when there's a particularly hot summer, you get (at least here in Switzerland) lots of news stories about poor very poor harvests due to the heat. With a 2-5C increase, nearly all summers will be particularly hot, and nearly all harvests will be particularly poor. And we simply will not have enough food in the world.

droithomme 14y ago

I like the part where they say that actual observed data is unreliable so they'll use a made up model instead to prove their claims. > "Satellite observations of clouds are sketchy, and contain errors."

dmlorenzetti 14y ago
they say that actual observed data is unreliable so they'll use a made up model instead to prove their claims. A better paraphrase would be "they say that accurate data on one part of the system are hard to get, so they compared several models using another, correlated, part of the system, for which better data are readily available." Also, since their claims relate to which of 16 models match "actual observed data" best, it's incorrect to characterize their work as using a model to prove their claims. The models are the subject of their claims, not tools used to prove them.
justsee 14y ago
I think you're misrepresenting the facts with your response, as the article actually states they decided to use humidity data rather than satellite data of clouds, because "conveniently, high-quality relative humidity data is readily available from satellites". I'm not sure how you can determine whether their approach is good or bad from that article.
jws 14y ago
You mean the part where they built their model off the accurately measurable water vapor content instead of building it off of the ambiguous reflectivity? [Edit: ok, let's not all pile on.]
- deleted 14y ago
  [deleted]
guscost 14y ago
Looks like the climate police don't appreciate your objection. Figures.

drivebyacct2 14y ago

I swear there is a common denominator between the dissonance that allows people to find any tiny thing they can to confirm their beliefs even the in the face of growing and yet already insurmountable evidence. For years climate change skeptics held on to one or two prominent scientists who disagreed. They've both recanted and apologized and urged a reexamination of the science, yet doubters just latched onto something else. Or, in the case of droithomme, find some half-invented ad hominem attack to use to dismiss the ENTIRE body of science on the issue. It's the same people that swore to me, up and down, bet me and made foolish statements that Romney was going to have some magic emotional boost and that Nate Silver was the devil working for the liberals and that his numbers were "wrong". That you don't like the facts or that they don't fit with your world view does nothing to make them any less true.

inthewoods 14y ago
They seem to be following a familiar pattern: - First, deny that temps are rising. - Next, admit they are rising, but that it isn't caused by humans. - Next (and perhaps finally), admit they rising, and that it is caused by humans, but state that there's nothing that can be done about it anyway.
guscost 14y ago
You seem to be fond of exaggeration.
- drivebyacct2 14y ago
  Oh! No wonder you're trolling me. After a glance at your comments, I accidentally nailed you spot on for both global warming and Nate Silver without even realizing your last page of comments is denial of both! I don't know why you're calling me names. I made a single comment that had to do with the actual issue of global warming and now that's grounds for me being a climate change zealot? I'll ask you again, do you realize that dismissing science as zealotry with no actual evidence or argument makes your position look less legitimate?
  - 14y ago

guscost 14y ago

I don't trust this study, because I don't trust National Geographic with regard to this issue. Go ahead and shame the disbeliever, I'm used to it.

drivebyacct2 14y ago
You know, when you come by, write a controversial one-line dismissal of an article, mock anyone who might disagree or even just wonder why you feel that way, and offer NO explanation or reasoning.... that is called trolling. The name-calling and accusations elsewhere are just further evidence.
deleted 14y ago
[deleted]

waterlesscloud 14y ago

I'm always cautious of the models as you get to the more extreme cases. To me it seems likely that as you get further and further from the current state that there are unknown factors lurking somewhere. Those factors may represent positive feedback, they may be negative feedback, or they may not exist at all. But to me the further into the unknown we go, the further into the unknown we are, if that makes sense. To be absolutely clear, I think the models probably work well enough for the near range. It's the far ranges I wonder about.

patrickgzill 14y ago

We were told back in the late 1980s and early 1990s that huge computer models were written, that ran on supercomputers, to model and predict climate change. The fastest Cray in 1990 could do (I think) 60 GFlops when loaded with 32 processors, which is roughly the sustained GFlops as a high end i7. So clearly it is not a case of "just need a faster supercomputer and we will have an accurate prediction". Reality is, from what I can tell, is that we don't have an accurate mathematical model of all the pieces that go into global climate to run on a supercomputer, no matter how powerful.

guscost 14y ago
Bingo.
oscilloscope 14y ago
We don't even have a particularly good data model. If you're interested in the water cycle, you'll have to construct that data from dozens of agencies in hundreds of governments. If the data was collected, linked together and published in an accessible form, more people could experiment with statistics, machine learning and visualization. Right now the data is in labyrinthine web forms, SOAP services, XLS files, GIS systems, etc. The barrier to entry needs to be lower.
macavity23 14y ago
Agreed. And even then, the system you're dealing with is so 'chaotic' (i.e. massive effects can be caused by very small changes in data) that you get diminishing returns the more data you have. Take the weather forecast as a (very) slimmed-down version of this problem. Yes, weather forecasts are better now than they were 20 years ago, but how much better? In the UK now, the 24h forecast is pretty accurate most of the time, but the three-day is very iffy, and a week out is still a crap shoot. That's despite a metric fuckton of satellite data and some serious hardware (the UK met office numbercruncher consumes more than a megawatt!). We're always going to be making guesses here. It seems, to my non-climatologist brain anyway, that the most up-to-date models produce predictions that are fairly consistent with the real world data we have. I would say the political and economic problems are much more important, and harder to solve.