6 ms·

Facts about global warming that you should keep for yourself

25 points by joeyespo 14y ago

saraid216 14y ago
Global warming is one of those topics I've always withheld judgement on because it's such a huge topic that, even ignoring politics, it seems very hard to get a solid understanding of the science.
- bryanlarsen 14y ago
  Unfortunately, by deciding to be "neutral" on the issue, you're exactly where the climate change deniers want you to be. The deniers don't have to be proven correct to prevent action on climate change, they just have to put out enough FUD to create doubt.
  - dredmorbius 14y ago
    As IBM and Microsoft were aware, to win with FUD (fear, uncertainty, doubt), they didn't have to convince you to buy their product, they just had to convince you not to buy the competitions', thereby starving the competition out. Cigarettes, seat belts, lead paint, asbestos, Linux, climate change. They've all been fought using the same tactics.
  - Strangiato 14y ago
    There is no need to ascribe malice to those that disagree with you about climate change issues. Reasonable people can disagree, especially on an issue that is complex and depends on predictions about future conditions.
    - anthonyb 14y ago
      It doesn't depend on predictions. Climate change is happening; the models are just to try and figure out how much warmer it's going to get, and how soon.
  - jack-r-abbit 14y ago
    But from the "deniers" side it is the "what ever you call the opposite of deniers" who are using FUD.
  - TheAmazingIdiot 14y ago
    Most of the real changes would require many people to die. Going back, worldwide, to a pre-industrial civilisation would be a possibility. However, We're looking at 90% fatality rates to get to that point due to lack of food production. Probably would be even less than that. No chance in happening, unless forced by catastrophic event. Another possibility is tremendous rationing. We see what having even simple healthcare is in this country. Instead, we would look at rationing everything in the world, including determining who lives and dies by how much resources they use (carbon debt). With 2 high input/output countries, good luck on this happening either. And we have to look at all the smaller ways to handle global warming. One proposal is to dump megatonnes of lime in the ocean?! Or perhaps this carbon credits scam: it makes the rich richer (Well, where DOES the money go?). At least sources of energy like solar or wind make sense... Until you realise the amount of energy to make a solar panel is greater than the total energy you will get out of it. Bummer. And underlying is this assumption that global warming == CO2 peak.. I've heard of this law called thermodynamics. CO2 may trap heat, but heat generated anywhere is still heat. We generate heat via our vehicles, electric grid, generators, burn piles, and other human sources of heat. Is this not a direct consideration as well?
    - DennisP 14y ago
      A study about a year ago claimed that we could get to half the reductions required to keep us under +2C just by halting all fossil fuel subsidies worldwide (not that that's feasible). A little googling on solar panel energy cost found, for example, these links: http://solarbus.org/documents/pvpayback.pdf http://solarbus.org/documents/pvpayback.pdf http://www.theoildrum.com/node/3910 http://www.theoildrum.com/node/3910 which claim that energy payback of solar panels takes about three years. For various reasons I think we'd do better with advanced nuclear, such as integral fast reactors or molten salt reactors. Either would be safer than what we have now, proliferation-resistant, and produce a lot less nuclear waste with a much shorter lifetime. We could have a very energy-rich future without carbon emissions. As for carbon credits, a lot of economists advocate a "fee-and-dividend" scheme. Instead of trading credits, major source emitters simply pay a flat fee per ton of carbon, passing on the cost to the rest of us. The money is divided among all citizens, equal amount per person. Most people come out ahead (since the median emissions are less than the average), but since the dividend is constant and the new cost variable, everyone has more incentive to conserve. I've seen calculations for the contribution of waste heat and it's very minor compared to greenhouse gases. However, if our energy usage continues to grow exponentially on this planet it'll be a real problem in a couple hundred years: http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/ http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...
- nickpinkston 14y ago
  That's true - but when there's risk of something, you need to buy insurance. Alt. energy, geo-enginnering, and small CO2 taxes are all ways of hedging that we should deploy in some combination. We can't say "don't know, therefore do nothing".
  - CamperBob2 14y ago
    Spoken like a natural-born insurance salesman!
  - glenra 14y ago
    There's also a risk we'll have another ice age. Global warming might be considered insurance against that eventuality. Whatever the perfectly optimum average planetary temperature for human life is, it is exceedingly unlikely that it was achieved in 1990. (And actually seems pretty likely that it's a fair bit warmer than now.) Do we also need to actively "buy insurance" against meteor impacts?
    - nickpinkston 14y ago
      We, as a society, are really bad a planning for these things collective/non-pressing problems, and the data being hard to come by just adds to this. Your thinking is pragmatic only in a short term sense. Do you really need fire insurance? Only 1:1000 homes ever burn - I guess not then... The risk for very bad global warming problems (mass despeciation or crop loss, etc. in 100 years) even at 10% is a really bad consequence that requires some form of insurance. The risk for rock impact in 100 years is about 0.0002%, and we've got people tracking a ton of near earth objects and even some NASA work on how to deflect them. That's probably about $20M in insurance - probably too low, but yes we should care about these things. http://abcnews.go.com/Technology/story?id=98208&page=1 http://abcnews.go.com/Technology/story?id=98208&page=1
      - glenra 14y ago
        It's possible to spend too much on "insurance" and we almost certainly do that when it comes to climate. The general scientific consensus is that the next half-century of warming generally makes humanity better off. So this risk you presumably think we need to be actively trying to mitigate - as opposed to just doing the sort of stuff we do for asteroids - is predicated on the idea that current trends continue for a century. But 50-60 years is quite a long time when it comes to technology. Even if the models are right, by the time global warming starts to be a net negative rather than a net positive, our grandkids will have a lot better options to deal with it then than we do today. Our kids and grandkids will be richer, smarter, better fed (due to longer growing seasons and CO2 fertilization), and MUCH better informed than we are today. The best thing we can do for them is give them an economy that hasn't been crippled due to paranoia that any one PARTICULAR threat we can foresee today will doom their world. There are an infinite number of potential threats that aren't hurting us now but that we can imagine might hurt our grandkids. Only some of them will actually turn out to be a serious problem. Spending trillions or even billions of dollars of resources combatting any one such threat reduces their potential ability to address all the others. There's nothing wrong with caring about things like global warming, but there's quite a lot wrong with trying to "fix" it now. To put it in programming terms: "Premature optimization is the root of all evil."
- CamperBob2 14y ago
  I agree, and what annoys me is that as a supporter of public-school science education via www.ncse.com and other organizations, I find myself being dragged into debates I didn't want to participate in. NCSE in particular has decided to lump criticisms of climate education in with their original cause, which was to do something about widespread attempts on the part of religious people to subvert public-school biology curricula. Strong evidence for anthropogenic climate change exists, to the best of my understanding. However, it's roughly 3.4 gazillion times weaker than the evidence for evolution by natural selection. There are reasons why I am actively interested in helping with one fight but not the other... but the organizations that I support as proxies in the fight don't appear to understand or care. I'm not even sure how annoyed I should be about this state of affairs, frankly.
- anthonyb 14y ago
  Just talk to some scientists, maybe? Here's the Australian CSIRO's take: http://www.csiro.au/Outcomes/Climate/Understanding/State-of-the-Climate-2012.aspx http://www.csiro.au/Outcomes/Climate/Understanding/State-of-... They produce a nifty State of the Climate report every so often, which is pretty easy to understand. There's one just been released, in fact: http://www.csiro.au/Outcomes/Climate/Understanding/%7E/media/8E59FBA4F8A94FE4B84F01E271226316.pdf http://www.csiro.au/Outcomes/Climate/Understanding/%7E/media... Disclaimer: I currently work for the Bureau of Meteorology in Melbourne - as a programmer though, not a scientist.
kstenerud 14y ago
"Let us look at the predictions made in 1990: they predicted an increase in temperature of 0.3C per decade, plus minus 0.1C. Yet less than 0.2C of warming per decade was observed. To be blunt, they got it flat wrong." How much less than 0.2C was it? 0.3 +/- 0.1 means it can be anywhere from 0.2 to 0.4, so unless it was grossly under 0.2, it wasn't flat wrong. "there are alternatives to banning oil production: solar radiation management. We might be able to setup space mirrors or otherwise increasing the reflectivity of our atmosphere." ... "But keep in mind that we will soon run out of cheap oil in any case." In other words, "Fear not, for we might just come up with some miracle technology or something. It might just all work out in the end so just stay the course and don't worry!" If you're going to call out others for poorly reasoned arguments, at least have well reasoned arguments of your own.
- stonemetal 14y ago
  Also wasn't that 0.3C in a nothing done to avert it scenario? With various green efforts around the world I would expect it to not quite hit the mark.
  - allardschip 14y ago
    Despite all the green efforts, CO2 output from using fossil fuel still grows. Western economies barely, if at all, made a dent in their fossil fuel consumptions. Upcoming economies like China use more and more fossil fuels. I think its fair to say that we are nowhere near having a solution to reduce global CO2 output.
    - stonemetal 14y ago
      Then blame it on the economy gas use fell(or at least growth fell) significantly with the recession.
      - allardschip 14y ago
        Not significantly. The CO2 PPM count is going up, recession or not: http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html#global_growth http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html#global_...
inthewoods 14y ago
I always find it troubling when someone with a computer science background assumes that their knowledge naturally transfers to something like climate science. Climate science is about probability and huge multi-factor models - and most importantly - models that change as new knowledge and data appear. It's just my opinion, but that seems to me to be the opposite of what most computer scientists are taught. Obviously computer scientists incorporate new data and new thinking - but I don't think it's quite the same as constructing a statistical model of how climate works. And obviously there are exceptions - but in general, I think it's just a different mindset.
- dmlorenzetti 14y ago
  I agree that knowledge of computer science doesn't transfer directly to climate science. However, there's a lot about computer science that may help understand how climate models yield probabilistic outcomes (Monte Carlo, anyone?). On the subject, be a little careful equating probabilistic models and statistical models. At least in my experience, "statistical models" generally describes statistical fits to past data. Think of a polynomial whose parameters are chosen by least-squares fit to previous observations. These fits can be used to interpolate or extrapolate (to the future, or to different combinations of inputs). However, they don't encode any domain knowledge, and they can be extremely brittle when pushed outside the regimes from which they were derived. Most climate models, on the other hand, are deterministic, physics-based models. Some of the sub-models may have statistical fits in them, but the modeling is largely driven by some conceptual framework of how the physics drive the dynamic system (e.g., expressing conservation of mass and energy, and how spatial differences drive transport). Those deterministic climate models can be driven probabilistically-- meaning the uncertain inputs and parameters can be sampled from distributions of likely values. Aggregating all the results gives a probabilistic prediction. A lot of climate reports take this one step further, and aggregate results across multiple models. Most computer scientists will immediately "get" this part, even if they don't understand all the physics represented in the individual packages.
  - inthewoods 14y ago
    Excellent points - and important not to generalize about model construction. I have a degree in computer science, and most of my training consisted of solving problems where there was a single outcome - e.g. "does the compiler work?" When I moved into financial modeling, I really had to shift from the idea of one answer to the idea that the real world is exceptionally complex and difficult to model. I had to get comfortable with the idea that I might have an idea of the outcome based on a model, but, as you point out, this is probabilistic outcome. I found this article to have all the marking of someone with a similar background trying out a different profession without understanding probabilistic modeling, and, as you rightly point out, not understanding the deterministic portion of the models - the domain knowledge. Moreover, I think he expresses doubt in any model that doesn't turn out the right answer 100% of the time - to me, not understanding the complexity of the systems that are being modeled and definitely not understanding that it is, as the name "climate science" implies, science - you experiment, you gain new knowledge from new data, etc.

25 points by joeyespo 14y ago

Global warming is one of those topics I've always withheld judgement on because it's such a huge topic that, even ignoring politics, it seems very hard to get a solid understanding of the science.

bryanlarsen 14y ago
Unfortunately, by deciding to be "neutral" on the issue, you're exactly where the climate change deniers want you to be. The deniers don't have to be proven correct to prevent action on climate change, they just have to put out enough FUD to create doubt.
- dredmorbius 14y ago
  As IBM and Microsoft were aware, to win with FUD (fear, uncertainty, doubt), they didn't have to convince you to buy their product, they just had to convince you not to buy the competitions', thereby starving the competition out. Cigarettes, seat belts, lead paint, asbestos, Linux, climate change. They've all been fought using the same tactics.
- Strangiato 14y ago
  There is no need to ascribe malice to those that disagree with you about climate change issues. Reasonable people can disagree, especially on an issue that is complex and depends on predictions about future conditions.
  - anthonyb 14y ago
    It doesn't depend on predictions. Climate change is happening; the models are just to try and figure out how much warmer it's going to get, and how soon.
- jack-r-abbit 14y ago
  But from the "deniers" side it is the "what ever you call the opposite of deniers" who are using FUD.
- TheAmazingIdiot 14y ago
  Most of the real changes would require many people to die. Going back, worldwide, to a pre-industrial civilisation would be a possibility. However, We're looking at 90% fatality rates to get to that point due to lack of food production. Probably would be even less than that. No chance in happening, unless forced by catastrophic event. Another possibility is tremendous rationing. We see what having even simple healthcare is in this country. Instead, we would look at rationing everything in the world, including determining who lives and dies by how much resources they use (carbon debt). With 2 high input/output countries, good luck on this happening either. And we have to look at all the smaller ways to handle global warming. One proposal is to dump megatonnes of lime in the ocean?! Or perhaps this carbon credits scam: it makes the rich richer (Well, where DOES the money go?). At least sources of energy like solar or wind make sense... Until you realise the amount of energy to make a solar panel is greater than the total energy you will get out of it. Bummer. And underlying is this assumption that global warming == CO2 peak.. I've heard of this law called thermodynamics. CO2 may trap heat, but heat generated anywhere is still heat. We generate heat via our vehicles, electric grid, generators, burn piles, and other human sources of heat. Is this not a direct consideration as well?
  - DennisP 14y ago
    A study about a year ago claimed that we could get to half the reductions required to keep us under +2C just by halting all fossil fuel subsidies worldwide (not that that's feasible). A little googling on solar panel energy cost found, for example, these links: http://solarbus.org/documents/pvpayback.pdf http://solarbus.org/documents/pvpayback.pdf http://www.theoildrum.com/node/3910 http://www.theoildrum.com/node/3910 which claim that energy payback of solar panels takes about three years. For various reasons I think we'd do better with advanced nuclear, such as integral fast reactors or molten salt reactors. Either would be safer than what we have now, proliferation-resistant, and produce a lot less nuclear waste with a much shorter lifetime. We could have a very energy-rich future without carbon emissions. As for carbon credits, a lot of economists advocate a "fee-and-dividend" scheme. Instead of trading credits, major source emitters simply pay a flat fee per ton of carbon, passing on the cost to the rest of us. The money is divided among all citizens, equal amount per person. Most people come out ahead (since the median emissions are less than the average), but since the dividend is constant and the new cost variable, everyone has more incentive to conserve. I've seen calculations for the contribution of waste heat and it's very minor compared to greenhouse gases. However, if our energy usage continues to grow exponentially on this planet it'll be a real problem in a couple hundred years: http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/ http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...
nickpinkston 14y ago
That's true - but when there's risk of something, you need to buy insurance. Alt. energy, geo-enginnering, and small CO2 taxes are all ways of hedging that we should deploy in some combination. We can't say "don't know, therefore do nothing".
- CamperBob2 14y ago
  Spoken like a natural-born insurance salesman!
- glenra 14y ago
  There's also a risk we'll have another ice age. Global warming might be considered insurance against that eventuality. Whatever the perfectly optimum average planetary temperature for human life is, it is exceedingly unlikely that it was achieved in 1990. (And actually seems pretty likely that it's a fair bit warmer than now.) Do we also need to actively "buy insurance" against meteor impacts?
  - nickpinkston 14y ago
    We, as a society, are really bad a planning for these things collective/non-pressing problems, and the data being hard to come by just adds to this. Your thinking is pragmatic only in a short term sense. Do you really need fire insurance? Only 1:1000 homes ever burn - I guess not then... The risk for very bad global warming problems (mass despeciation or crop loss, etc. in 100 years) even at 10% is a really bad consequence that requires some form of insurance. The risk for rock impact in 100 years is about 0.0002%, and we've got people tracking a ton of near earth objects and even some NASA work on how to deflect them. That's probably about $20M in insurance - probably too low, but yes we should care about these things. http://abcnews.go.com/Technology/story?id=98208&page=1 http://abcnews.go.com/Technology/story?id=98208&page=1
    - glenra 14y ago
      It's possible to spend too much on "insurance" and we almost certainly do that when it comes to climate. The general scientific consensus is that the next half-century of warming generally makes humanity better off. So this risk you presumably think we need to be actively trying to mitigate - as opposed to just doing the sort of stuff we do for asteroids - is predicated on the idea that current trends continue for a century. But 50-60 years is quite a long time when it comes to technology. Even if the models are right, by the time global warming starts to be a net negative rather than a net positive, our grandkids will have a lot better options to deal with it then than we do today. Our kids and grandkids will be richer, smarter, better fed (due to longer growing seasons and CO2 fertilization), and MUCH better informed than we are today. The best thing we can do for them is give them an economy that hasn't been crippled due to paranoia that any one PARTICULAR threat we can foresee today will doom their world. There are an infinite number of potential threats that aren't hurting us now but that we can imagine might hurt our grandkids. Only some of them will actually turn out to be a serious problem. Spending trillions or even billions of dollars of resources combatting any one such threat reduces their potential ability to address all the others. There's nothing wrong with caring about things like global warming, but there's quite a lot wrong with trying to "fix" it now. To put it in programming terms: "Premature optimization is the root of all evil."
CamperBob2 14y ago
I agree, and what annoys me is that as a supporter of public-school science education via www.ncse.com and other organizations, I find myself being dragged into debates I didn't want to participate in. NCSE in particular has decided to lump criticisms of climate education in with their original cause, which was to do something about widespread attempts on the part of religious people to subvert public-school biology curricula. Strong evidence for anthropogenic climate change exists, to the best of my understanding. However, it's roughly 3.4 gazillion times weaker than the evidence for evolution by natural selection. There are reasons why I am actively interested in helping with one fight but not the other... but the organizations that I support as proxies in the fight don't appear to understand or care. I'm not even sure how annoyed I should be about this state of affairs, frankly.
anthonyb 14y ago
Just talk to some scientists, maybe? Here's the Australian CSIRO's take: http://www.csiro.au/Outcomes/Climate/Understanding/State-of-the-Climate-2012.aspx http://www.csiro.au/Outcomes/Climate/Understanding/State-of-... They produce a nifty State of the Climate report every so often, which is pretty easy to understand. There's one just been released, in fact: http://www.csiro.au/Outcomes/Climate/Understanding/%7E/media/8E59FBA4F8A94FE4B84F01E271226316.pdf http://www.csiro.au/Outcomes/Climate/Understanding/%7E/media... Disclaimer: I currently work for the Bureau of Meteorology in Melbourne - as a programmer though, not a scientist.

kstenerud 14y ago

"Let us look at the predictions made in 1990: they predicted an increase in temperature of 0.3C per decade, plus minus 0.1C. Yet less than 0.2C of warming per decade was observed. To be blunt, they got it flat wrong." How much less than 0.2C was it? 0.3 +/- 0.1 means it can be anywhere from 0.2 to 0.4, so unless it was grossly under 0.2, it wasn't flat wrong. "there are alternatives to banning oil production: solar radiation management. We might be able to setup space mirrors or otherwise increasing the reflectivity of our atmosphere." ... "But keep in mind that we will soon run out of cheap oil in any case." In other words, "Fear not, for we might just come up with some miracle technology or something. It might just all work out in the end so just stay the course and don't worry!" If you're going to call out others for poorly reasoned arguments, at least have well reasoned arguments of your own.

stonemetal 14y ago
Also wasn't that 0.3C in a nothing done to avert it scenario? With various green efforts around the world I would expect it to not quite hit the mark.
- allardschip 14y ago
  Despite all the green efforts, CO2 output from using fossil fuel still grows. Western economies barely, if at all, made a dent in their fossil fuel consumptions. Upcoming economies like China use more and more fossil fuels. I think its fair to say that we are nowhere near having a solution to reduce global CO2 output.
  - stonemetal 14y ago
    Then blame it on the economy gas use fell(or at least growth fell) significantly with the recession.
    - allardschip 14y ago
      Not significantly. The CO2 PPM count is going up, recession or not: http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html#global_growth http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html#global_...

inthewoods 14y ago

I always find it troubling when someone with a computer science background assumes that their knowledge naturally transfers to something like climate science. Climate science is about probability and huge multi-factor models - and most importantly - models that change as new knowledge and data appear. It's just my opinion, but that seems to me to be the opposite of what most computer scientists are taught. Obviously computer scientists incorporate new data and new thinking - but I don't think it's quite the same as constructing a statistical model of how climate works. And obviously there are exceptions - but in general, I think it's just a different mindset.

dmlorenzetti 14y ago
I agree that knowledge of computer science doesn't transfer directly to climate science. However, there's a lot about computer science that may help understand how climate models yield probabilistic outcomes (Monte Carlo, anyone?). On the subject, be a little careful equating probabilistic models and statistical models. At least in my experience, "statistical models" generally describes statistical fits to past data. Think of a polynomial whose parameters are chosen by least-squares fit to previous observations. These fits can be used to interpolate or extrapolate (to the future, or to different combinations of inputs). However, they don't encode any domain knowledge, and they can be extremely brittle when pushed outside the regimes from which they were derived. Most climate models, on the other hand, are deterministic, physics-based models. Some of the sub-models may have statistical fits in them, but the modeling is largely driven by some conceptual framework of how the physics drive the dynamic system (e.g., expressing conservation of mass and energy, and how spatial differences drive transport). Those deterministic climate models can be driven probabilistically-- meaning the uncertain inputs and parameters can be sampled from distributions of likely values. Aggregating all the results gives a probabilistic prediction. A lot of climate reports take this one step further, and aggregate results across multiple models. Most computer scientists will immediately "get" this part, even if they don't understand all the physics represented in the individual packages.
- inthewoods 14y ago
  Excellent points - and important not to generalize about model construction. I have a degree in computer science, and most of my training consisted of solving problems where there was a single outcome - e.g. "does the compiler work?" When I moved into financial modeling, I really had to shift from the idea of one answer to the idea that the real world is exceptionally complex and difficult to model. I had to get comfortable with the idea that I might have an idea of the outcome based on a model, but, as you point out, this is probabilistic outcome. I found this article to have all the marking of someone with a similar background trying out a different profession without understanding probabilistic modeling, and, as you rightly point out, not understanding the deterministic portion of the models - the domain knowledge. Moreover, I think he expresses doubt in any model that doesn't turn out the right answer 100% of the time - to me, not understanding the complexity of the systems that are being modeled and definitely not understanding that it is, as the name "climate science" implies, science - you experiment, you gain new knowledge from new data, etc.