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Dear Legor,
On August 23 2013 00:17 legor wrote:
Nobody knows if the net effects would be good or bad, and probably nobody can know. We are talking, after all, about effects across the world over a century. How accurately could somebody in 1900 have predicted what would matter to human life in 2000? What reason do we have to think we can do better?
Should we, for instance, assume that Bangladesh will still be a poor country a century hence, or that it will by then have followed the path blazed by South Korea, Taiwan, Singapore and Hong Kong—and so be in a position to dike its coast, as Holland did several centuries ago, or move housing some miles further inland, at a cost that can be paid out of petty change? Should we assume that population increase makes agricultural land more valuable and the expansion of the area over which crops can be grown more important, or that improvements in crop yield make it less? While there may be people who believe that they know the answer to such questions, the numbers required to justify such belief are at best educated guesses, in most cases closer to pure invention. Someone who wants to prove that global warming is bad can make high estimates for the costs, low estimates for the benefits, and so prove his case to his own satisfaction. Someone with the opposite agenda can reverse the process and prove his case equally well.
If we cannot calculate in any detail what the actual consequences of global warming and associated costs and benefits will be, an alternative is to ask whether we have any reason to expect, a priori, that costs will be larger than benefits. There are, I think, two answers.
The first is that any change, whether warming or cooling, is presumptively bad, because current human activity is optimized against current conditions. Farmers grow crops suited to the climate where they are growing them; a change in climate will require a costly change in what they grow and how they grow it. Houses are designed for the climate they are built in and located in places not expected, under current circumstances, to flood. Putting it in economic terms, we have born sunk costs based on the current environment, and a change in that environment will eliminate some of the quasi-rents that we expected as the return for those costs.
This is a real argument against rapid change. But the global warming controversy involves changes over not a year or a decade but a century. Over a century, most farmers will change the crop they find it most profitable to grow multiple times; if average temperatures are trending up, those changes will include a shift towards crops better suited to slightly warmer weather. Over a century, most houses will be torn down and replaced; if sea level is rising, houses currently built on low lying coastal ground will be rebuilt a little farther inland—not much farther if we are talking, as the IPCC estimates suggest we should be, about a rise of a foot or two. Hence the presumption that change is bad is a very weak one for changes as slow as those we have good reason to expect from global warming.
It is hard to see any other reason to expect gobal warming to make us, on net, worse off. The earth and its climate were not, after all, designed for our convenience, so there is no good reason to believe that their current state is optimal for us. It is true that our species evolved to survive under then existing climatic conditions but, over the period for which humans have existed, climate has varied by considerably more than the changes being predicted for global warming. And, for the past many thousands of years, humans have lived and prospered over a range of climates much larger than the range that we expect the climate at any particular location to change by.
If we have no good reason to believe that humans will be substantially worse off after global warming than before, we have no good reason to believe that it is worth bearing sizable costs to prevent global warming.
This is a considerate post, and I think it is much more rational to discuss policy options and reasons for them than to attack the underlying science.
Just a few quick comments (most of them personally, because I dont have much professional experience with climat eimpact studies): I personally agree that agriculture will be fine. There is enough money behind it, people will find plants that grow. Additionally, the time scale of changes is slow wrt agriculture. But, see last point. I personally dont agree about sea level rise: wrt to migration of up to billions, the time scales are slow but still significant. It is technically feasible, sure, but it will involve gigantic political and economic costs to move or protect century old cities (this will btw not e necessary in 2100 by any means, this is more a even longer term thing).
Last point: besides direct temperature and precipitation influence, the result of climate change that will most likely be massively detrimental to us, already in this century, will be changes or increases in weather extrems, like monsoons, dry periods, cold winters, hot summers, and so on.
In summary: if we believe that a "business as usual" policy will strengthen local economy and adaptation potential, it might be a viable political strategy to say, lets ignore CO2 right now and hope that we will be able to deal with it later. There are economists who say that this is probably not beneficial to the global GDP, but who know sif this is the relevant metric, after all.It is however, a policy not on the side of caution and restraint wrt to our following fellow humans, so I personally would not follow said policy. It will also blame most of the burdens of todays and yesterdays emissions on developing countries in asia and Africa, which again is okay for a realistic policy, but nothing I would argue for. But that is one of the aforementioned value decisions, not a scientific one.
Best regards,
W
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On August 23 2013 01:09 GreenGringo wrote:Show nested quote +On August 22 2013 21:23 Darkwhite wrote:
I am not expecting you to read a study. Someone else posted a single graph, and I wanted to discuss what the results meant. I also provided a source for my guess that the model was designed in 2008, such that everything up to this point is post hoc fitting, while the rest are predictions. If you insist to keep the discussion entirely free of results and data, we'll be left with nothing but peacocking. I'm sorry, but this is a distortion that is so at odds with the post history in this thread that it verges on deception. I never said or hinted that I think the discussion should be free of results and data. I only wanted something more concrete to substantiate your claim that climate scientists arrive at their models by twiddling with free variables to retrospectively fit the data. Show nested quote +On August 22 2013 21:23 Darkwhite wrote:I did not intend to specifically claim that they have fitted entirely free variables. I meant to say that any idiot can give you a perfectly backwards fitted curve in five minutes by Fourier expansion, and that for this reason, I consider the post hoc extremely weak evidence, particularly when the forwards fit is poor. But nobody was TRYING to use that model as evidence for climate change. Rather you were trying to use it as evidence against climate change. Designing a curve by tweaking arbitrary variables to retrospectively fit the data is such an obvious scientific howler that it seems RIDICULOUS to suggest that climate scientists are doing it. That's why I asked for evidence to support your piece of slander. By all means continue to use whatever data you like. But don't make claims about it that you know you can't support and don't speculate that climate scientists are incompetent buffoons who use whatever boundary conditions and arbitrary parameters they feel like.
The only thing I have done is to point towards the graph as an example of the unreliability of predictions about the future.
The following quote seemed to me to be quite the showstopper, as far as discussing actual data goes:
So I'm supposed to read every link posted by every denialist on a forum? No. The burden of proof is on HIM, not on me for subscribing to the overwhelming consensus of climate scientists, borne out by all kinds of disparate and mutually reinforcing evidence they have.
I bear the burden of proof, and you are not going to bother reading up on whatever proof I might present. A single graph can be brushed aside as insignificant, while real reading is off the table as something you can't be expected to do.
Dabbeljuh seems to recognize that overfitting is a potential problem in climate science, even though tweaking arbitrary variables is a strawman representation. See:
your arguments concerning using training data as verification data are partially warranted, though not completely correct. We as in the climate science community are aware of this problem and try to design tests that are meaningful.
The actual mechanism is that a selection bias for models which agree with historical developments puts you at risk of overfitting, while the difficulty of obtaining good test data makes it hard to counteract this.
On August 23 2013 00:45 dabbeljuh wrote:Dear Darkwhite, Show nested quote +On August 22 2013 23:38 Darkwhite wrote:
I am saying that the results I have seen are not enough to place trust in either their projections for climate change nor their calls for policy revision. I really don't see why you take offense at having climate science compared to economics or psychology. Both are legitimate sciences, they just happen to dealing with extremely complicated systems, which sets them very firmly apart from the reliability of the more familiar parts of physics, such as gravity and astronomy.
If you think this is too definite a claim for a well-educated physicist to make, then we'll just have to disagree.
I have never said climate science suffers from priming - the link details how one of the progenitor experiments of priming is probably a false positive. You really need to spend less time making false inferences about what I'm writing. I agree that climate science differs from a "clear" natural science as gravity or astronomy, I dont agree that you can directly compare it to economics and psychology. The reasons have been mentioned above, the root of climate sciences are physics, observations and reproducable and falsifiable hypotheses.
Psychology and economics are mostly based on the same sort of experimental verification, pointing to datasets and quoting confidence values at every possible occasion. The primary difference between these two and physics, as far as I can see, is the complexity of the systems they study.
An hypothesis cannot not be reproducible - that doesn't even make sense. Physics is based on reproducible experiments which can falsify hypotheses. While some of the effects involved in climate change can be studied in laboratory environments and extrapolated to the global scope, there is nothing which smacks of either reproducible or falsifiable insofar as the global warming hypothesis is concerned. This, coupled with apparent indifference towards the only sort of verification possible for these models, i.e. future developments, strikes me as worrisome.
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On August 23 2013 01:11 dabbeljuh wrote:
In summary: if we believe that a "business as usual" policy will strengthen local economy and adaptation potential, it might be a viable political strategy to say, lets ignore CO2 right now and hope that we will be able to deal with it later. There are economists who say that this is probably not beneficial to the global GDP, but who know sif this is the relevant metric, after all.It is however, a policy not on the side of caution and restraint wrt to our following fellow humans, so I personally would not follow said policy. It will also blame most of the burdens of todays and yesterdays emissions on developing countries in asia and Africa, which again is okay for a realistic policy, but nothing I would argue for. But that is one of the aforementioned value decisions, not a scientific one.
In regards to this paragraph, I have a few questions for you. Are developing countries expending the most CO2? (Also if there is data on CO2 output of different regions or countries I'd love to read through it) If they develop, do they stop releasing as much? To what effect do you feel conscious consumerism could curb global warming (i.e. voting with your wallet and not supporting companies that release unnecessarily high amounts of CO2). What steps could one take personally to help curb CO2 output without forcefully requiring others to do so? Are there any effects of global warming that could be incredibly difficult to adapt to?
p.s. Thanks for the thread, it really got me started on reading more into the subject.
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On August 23 2013 01:58 Darkwhite wrote:
I bear the burden of proof, and you are not going to bother reading up on whatever proof I might present. A single graph can be brushed aside as insignificant, while real reading is off the table as something you can't be expected to do. Not much to say other than that your reading comprehension sucks or you're lying.
The "proof" I was referring to was the proof of your claim that climate scientists arrive at their models by playing with free variables. A claim which you still have failed to corroborate. The burden is on YOU to prove that -- not on me to chase up the paper trail stemming from your fourth-hand source. A 14-year-old could come in here, disagree with climate scientists and say "Climate scientists are using random equations -- here is a body of literature that proves I'm right". The null hypothesis is he's bullshitting and unless he gives compelling scholarly arguments or a very detailed reference (citation together with quotations or page number -- not a paper trail), then proving him wrong is almost certainly not going to be worth the time investment.
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True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase.
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United States24740 Posts
On August 23 2013 03:25 TheOneWhoKnocks wrote:
True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase.
I believe it would continue to increase. However, the 'turnaround point' would come sooner than if humans were not to suddenly vanish. The Earth has a lot of 'inertia.'
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On August 23 2013 03:45 micronesia wrote:Show nested quote +On August 23 2013 03:25 TheOneWhoKnocks wrote:
True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase. I believe it would continue to increase. However, the 'turnaround point' would come sooner than if humans were not to suddenly vanish. The Earth has a lot of 'inertia.'
If my statement is true, then there is no turnaround point.
No policies we enact could ever make as significant a dent in CO2 emissions as eliminating the entire US. It is therefore necessary to admit that we cannot stop CO2 concentration from increasing, and therefore cannot stop global warming. We can only delay it, and probably for less than a week.
What, then, is the real purpose of CO2 legislation?
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United States24740 Posts
On August 23 2013 04:07 TheOneWhoKnocks wrote:Show nested quote +On August 23 2013 03:45 micronesia wrote:On August 23 2013 03:25 TheOneWhoKnocks wrote:
True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase. I believe it would continue to increase. However, the 'turnaround point' would come sooner than if humans were not to suddenly vanish. The Earth has a lot of 'inertia.' If my statement is true, then there is no turnaround point.
How did you arrive at this conclusion? You must not be sharing all of your information because that is not apparent from what you have said in this conversation (specifically the quote chain above).
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Why would there be no turnaround point? Wouldn't the appropriate question be - what is the difference in CO2 increase from nature and from humans?
And also - how can you say that we cannot stop CO2 concentration from increasing/cannot stop global warming? Are we to limit ourselves from studying solutions just because we ourselves are limited by our current technologies?
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On August 23 2013 04:15 micronesia wrote:Show nested quote +On August 23 2013 04:07 TheOneWhoKnocks wrote:On August 23 2013 03:45 micronesia wrote:On August 23 2013 03:25 TheOneWhoKnocks wrote:
True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase. I believe it would continue to increase. However, the 'turnaround point' would come sooner than if humans were not to suddenly vanish. The Earth has a lot of 'inertia.' If my statement is true, then there is no turnaround point. How did you arrive at this conclusion? You must not be sharing all of your information because that is not apparent from what you have said in this conversation (specifically the quote chain above).
You can't have a turnaround point if CO2 is perpetually increasing. I'm not sure what more information you need.
So long as humans and industry exist, it will be emitting CO2, which means the global concentration will be increasing. Legislation can't stop the decrease, only the rate of increase. Sure, there is some "maintenance level" of CO2 that nature can absorb back, but you don't think that we are anywhere close to that do you?
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On August 23 2013 02:36 renoB wrote:Show nested quote +On August 23 2013 01:11 dabbeljuh wrote:
In summary: if we believe that a "business as usual" policy will strengthen local economy and adaptation potential, it might be a viable political strategy to say, lets ignore CO2 right now and hope that we will be able to deal with it later. There are economists who say that this is probably not beneficial to the global GDP, but who know sif this is the relevant metric, after all.It is however, a policy not on the side of caution and restraint wrt to our following fellow humans, so I personally would not follow said policy. It will also blame most of the burdens of todays and yesterdays emissions on developing countries in asia and Africa, which again is okay for a realistic policy, but nothing I would argue for. But that is one of the aforementioned value decisions, not a scientific one.
In regards to this paragraph, I have a few questions for you. Are developing countries expending the most CO2? (Also if there is data on CO2 output of different regions or countries I'd love to read through it) If they develop, do they stop releasing as much? To what effect do you feel conscious consumerism could curb global warming (i.e. voting with your wallet and not supporting companies that release unnecessarily high amounts of CO2). What steps could one take personally to help curb CO2 output without forcefully requiring others to do so? Are there any effects of global warming that could be incredibly difficult to adapt to? p.s. Thanks for the thread, it really got me started on reading more into the subject.
To but in..
Developed countries produce the most CO2 as CO2 production is largely a product of economic activity. Developing countries are responsible for the recent and projected future increases in CO2 production as their economies grow faster and catch up to the developed world.
Developing countries also tend to produce more CO2 per unit of economic activity because they rely more on industry and raw material production (factories, mining, drilling, etc). As economies advance they use less energy per unit of economic activity as they move to less energy intensive services. Right now, advanced economies are also more able to afford clean energy over cheaper fossil fuels which has also retarded the growth of CO2 generation in those countries.
On the last point of clean energy, many forms (like solar) are expected to reach cost parity with various fossil fuels within the decade, unsubsidized, which should be an important game changer going forward.
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Hey there, I've got a few questions for the climate scientists in the thread. My background is chemistry and optics, so please excuse me if this comes off as dumb, but, when you develop the climate models, do you really just solve N-dimensional systems of equations? One of Darkwhite's problems seems to be that, if you take the available data, assume it is a function of N-variables, fit the variables over a given time period and, if it's not accurate enough, do it for N+1, you'll eventually be able to fit the previously-observed trends. But, is this how the models are actually developed? Or, do you model the Earth simply as a rotating sphere(oid) with specific thermodynamic assumptions (energy input from the sun, dissipation across the earth, different absorption properties in different areas, etc.) and let the model run starting at time=150+ years ago? Then, if it doesn't match observations, add the effects of volcanoes, ocean currents, etc. It seems that in the former, Darkwhite's concerns certainly are legitimate, but in the latter, you cannot really argue against adding MORE information into a simulation. I don't mean to make it sound like Darkwhite is arguing against adding more information into a simulation, his comments seem more directed to solving arbitrary N-dimensional systems.
Also, I suppose this is a little pet-peeve of mine related to the "sanctity of physics" vs social sciences, but physics isn't reproducible at all scales anyways. Sorry, but I feel like physics is elevated as an unassailable truth, when in fact its limitations are just better-characterized. Think about picking an atom at random out of an ensemble and measuring its energy for a given ensemble temperature. You don't know what the energy will be, you can only predict statistically what range it should be in. Same thing as the position vs momentum of an atomic particle. But, you don't feel bad about it, cause the next person who comes along cannot do any better than you. Climate science is like economics and psychology because it is physics-based, that is, you concede that you cannot know every single detail simultaneously. You just work at the scale relative to the system of interest to extract meaningful information.
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United States24740 Posts
On August 23 2013 04:30 TheOneWhoKnocks wrote:Show nested quote +On August 23 2013 04:15 micronesia wrote:On August 23 2013 04:07 TheOneWhoKnocks wrote:On August 23 2013 03:45 micronesia wrote:On August 23 2013 03:25 TheOneWhoKnocks wrote:
True or False?
If every human being and machine in the United States were to vanish from the Earth, the total CO2 concentration of the atmosphere would continue to increase. I believe it would continue to increase. However, the 'turnaround point' would come sooner than if humans were not to suddenly vanish. The Earth has a lot of 'inertia.' If my statement is true, then there is no turnaround point. How did you arrive at this conclusion? You must not be sharing all of your information because that is not apparent from what you have said in this conversation (specifically the quote chain above). You can't have a turnaround point if CO2 is perpetually increasing. I'm not sure what more information you need.
Why do you think CO2 is perpetually increasing? There are many factors that influence whether it goes up or down.
I agree with you that CO2 would continue to go up if human industry suddenly disappeared, at least at first. However, that does not mean that CO2 is perpetually increasing, or that the increase immediately after humans disappeared would be natural (not of human origin).
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On August 23 2013 04:33 TallMax wrote:
It seems that in the former, Darkwhite's concerns certainly are legitimate, but in the latter, you cannot really argue against adding MORE information into a simulation. I don't mean to make it sound like Darkwhite is arguing against adding more information into a simulation, his comments seem more directed to solving arbitrary N-dimensional systems. Bear in mind that he didn't allude to so much as a whiff of evidence that could support that speculation about the methodologies of climate scientists. When challenged, he backed down and prevaricated with some waffle about how the existence of a curve that fits past data can't be used as evidence. Very good, but nobody said that it should be used as evidence of climate change. For that we have a bunch of other things.
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On August 23 2013 02:36 renoB wrote:Show nested quote +On August 23 2013 01:11 dabbeljuh wrote:
In summary: if we believe that a "business as usual" policy will strengthen local economy and adaptation potential, it might be a viable political strategy to say, lets ignore CO2 right now and hope that we will be able to deal with it later. There are economists who say that this is probably not beneficial to the global GDP, but who know sif this is the relevant metric, after all.It is however, a policy not on the side of caution and restraint wrt to our following fellow humans, so I personally would not follow said policy. It will also blame most of the burdens of todays and yesterdays emissions on developing countries in asia and Africa, which again is okay for a realistic policy, but nothing I would argue for. But that is one of the aforementioned value decisions, not a scientific one.
In regards to this paragraph, I have a few questions for you. Are developing countries expending the most CO2? (Also if there is data on CO2 output of different regions or countries I'd love to read through it) If they develop, do they stop releasing as much? To what effect do you feel conscious consumerism could curb global warming (i.e. voting with your wallet and not supporting companies that release unnecessarily high amounts of CO2). What steps could one take personally to help curb CO2 output without forcefully requiring others to do so? Are there any effects of global warming that could be incredibly difficult to adapt to? p.s. Thanks for the thread, it really got me started on reading more into the subject.
It is often the other way around. Developed countries and oil states release the most CO2 or greenhouse gasses. You can look up "carbon footprint" for a measure and a list of countries by greenhouse gas emission can be found here. The problem of developing countries is their increase in emission and that increase is a significant part of the problems in discussions on the Kyoto protocol and other global treaties.
Conscious consumerism would be using mass transit or even better a transportation running on second/third generation biofuels, cycle/walk, avoiding unnecesssary plastic, low electricity use, low heat use, vegetarian local diet, preferrably homegrown etcetera. etcetera. Well, if you look at the WRI report on the subject (which is a bit "outdated" so don't trust the exact numbers!), most of the problems are with deforestation, industrial uses and farming where the conscious consumer needs quite the knowledge and quite the numbers to effectively improve the situation. Also, energy is the biggest sector and to change the situation there, you have to fiddle with the incentives to increase production of the more expensive green energy. All in all a single persons choices are a bit limited in the overall picture. Fortunately a lot of companies have found out that they can actually save money or at least break even by getting more environmentally friendly and that is helping.
The exact effects of global warming are still uncertian. I would imagine that more powerful tornados are relatively hard to adapt to, but that is a regional problem.
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Dear Renob,
On August 23 2013 02:36 renoB wrote:
In regards to this paragraph, I have a few questions for you. Are developing countries expending the most CO2? (Also if there is data on CO2 output of different regions or countries I'd love to read through it) If they develop, do they stop releasing as much? To what effect do you feel conscious consumerism could curb global warming (i.e. voting with your wallet and not supporting companies that release unnecessarily high amounts of CO2). What steps could one take personally to help curb CO2 output without forcefully requiring others to do so? Are there any effects of global warming that could be incredibly difficult to adapt to?
p.s. Thanks for the thread, it really got me started on reading more into the subject.
A few comments:
- here is a list of co2 emissions (top10)
http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions#List_of_countries_by_2011_emissions_estimates or all
http://edgar.jrc.ec.europa.eu/overview.php?v=CO2ts1990-2011
so no, the most CO2 is still produced in the developed countries, +BRIC. It is interesting, though, to look at emissions per capita, where some of the developing countries are still far away from global average (India), while some are approaching global average levels (China) even thouhg their per capita GDP is far from average. This has mostly to do with a "bad" energy production system, too much coal.
- If countries develop, they usually increase their energy efficiency, so they decrease CO2 / GDP. This already happens for China and India. Unfortunately, in most cases the GDP grows faster than this energy efficiency increase, so that most countries continue to increase their emissions for quite some time. There is no general theory as to when this stops, but in the developed countires it usually just stopped because we outsorced energy intensive production into developing countries °J
- The strongest influence you have on your personal CO2 emissions without bothering others are food and travel (energy efficiency at home is probably followup). Food as in local, vegetarian food (and chicken) is much better than pork or beef (or 40%+fat cheese, unfortunately, so its not as easy as becoming vegetarian =). Travel: every intercontinental flight has the potential to double your yearly CO2 emissions.
- I believe that western countries with sufficient money will be able to adapt to all direct climate changes of the 21st century. Most difficult will be things like Sandy or heat and drought periods, if they get stronger and more frequent, this is still unsure. I am not so sure with respect to Africa and Asia, or essentially all areas where there is hunger today. Those countries will be disproportionately affected by increased droughts and change in agricultural system due to changes in temperature and precipitation patterns.
I hope that helps as a starter, feel free to PM or ask again here,
W
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Hey Tallmax,
On August 23 2013 04:33 TallMax wrote:
Hey there, I've got a few questions for the climate scientists in the thread. My background is chemistry and optics, so please excuse me if this comes off as dumb, but, when you develop the climate models, do you really just solve N-dimensional systems of equations? One of Darkwhite's problems seems to be that, if you take the available data, assume it is a function of N-variables, fit the variables over a given time period and, if it's not accurate enough, do it for N+1, you'll eventually be able to fit the previously-observed trends. But, is this how the models are actually developed? Or, do you model the Earth simply as a rotating sphere(oid) with specific thermodynamic assumptions (energy input from the sun, dissipation across the earth, different absorption properties in different areas, etc.) and let the model run starting at time=150+ years ago? Then, if it doesn't match observations, add the effects of volcanoes, ocean currents, etc. It seems that in the former, Darkwhite's concerns certainly are legitimate, but in the latter, you cannot really argue against adding MORE information into a simulation. I don't mean to make it sound like Darkwhite is arguing against adding more information into a simulation, his comments seem more directed to solving arbitrary N-dimensional systems.
.
It is more similar to your second variant: the models people usually call climate models are a coupled system of two global fluid solvers: atmosphere and ocean. Those are - in a very simple way - just equations of motion of air and water. Coupled into these systems are radiative transfer models, that simulate what sunshine does when it hits water, particles or ground. At the ocean atmosphere interface there are simulators, that activate when ice forms and that change in the following albedo, surface roughness and so on. In the end result, these system are just "started" from a steady state of atmosphere and ocean in rest. Given a rotatingn Earth and a resulting daily radiation forcing, the system starts to oscillate, move, behave chaotically. This is the so called preindustrial control, a steady state of an ever changing Earth. Already here, things like El Nino, the QBO, Moonsson, Tornados and stuff just start via emergence in the system. They are not "put into the model", they are exhibited by the model because it simulates the physical basis of the system.
Then, starting from the 1850s, a forcing is put into the system, telling the atmosphere, how much CO2 , also from human emissions, from volcanoes et cetera has been there as far as we know. The system is run for 150 years and reacts to that forcing and in the result we see two lines: a more or less continous "control" and the socalled "historical" run. From 2000 on, we only subscribe solar and CO2 (and aerosol, and xxx )forcing, no volcanoes anymore because we cannot predict them. This is why the curves get smoother.
So, in a way we let the model run, but we always have to feed it with boundary conditions. OVerall, we treat Earth as a stochastic partial differential euqation with time dependent boundary conditions, if this is of any help.
Feel free to ask again if this is too technical / not technical enough 
Best regards
W
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On August 23 2013 03:15 GreenGringo wrote:Show nested quote +On August 23 2013 01:58 Darkwhite wrote:
I bear the burden of proof, and you are not going to bother reading up on whatever proof I might present. A single graph can be brushed aside as insignificant, while real reading is off the table as something you can't be expected to do. Not much to say other than that your reading comprehension sucks or you're lying. The "proof" I was referring to was the proof of your claim that climate scientists arrive at their models by playing with free variables. A claim which you still have failed to corroborate. The burden is on YOU to prove that -- not on me to chase up the paper trail stemming from your fourth-hand source. A 14-year-old could come in here, disagree with climate scientists and say "Climate scientists are using random equations -- here is a body of literature that proves I'm right". The null hypothesis is he's bullshitting and unless he gives compelling scholarly arguments or a very detailed reference (citation together with quotations or page number -- not a paper trail), then proving him wrong is almost certainly not going to be worth the time investment.
They are not using random equations. They are basing their equations on data, which is what every sensible science must do. However, the observations made prior to the model being published is both being used explicitly, to determine empirical constants, and implicitly, to discard models with poor match. For this reason, backwards matching is at best very tenuous proof of the models' validity.
As an example, I have explained how I can fit any dataset to any level of accuracy by doing a simple Fourier expansion. This is, of course, the extreme end of using only free variables. I am not suggesting that climate scientists are literally doing this. What I am saying is some free variable selection bias will still sneak in, by the two mechanisms explained in the above paragraph, and the best way to gauge the model independent of this is to focus on its forwards predictive accuracy.
The only thing I have asked you to verify yourself from the source is the publication year of the model in question, because I wasn't quite certain it was from 2008.
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On August 23 2013 05:55 Darkwhite wrote:Show nested quote +On August 23 2013 03:15 GreenGringo wrote:On August 23 2013 01:58 Darkwhite wrote:
I bear the burden of proof, and you are not going to bother reading up on whatever proof I might present. A single graph can be brushed aside as insignificant, while real reading is off the table as something you can't be expected to do. Not much to say other than that your reading comprehension sucks or you're lying. The "proof" I was referring to was the proof of your claim that climate scientists arrive at their models by playing with free variables. A claim which you still have failed to corroborate. The burden is on YOU to prove that -- not on me to chase up the paper trail stemming from your fourth-hand source. A 14-year-old could come in here, disagree with climate scientists and say "Climate scientists are using random equations -- here is a body of literature that proves I'm right". The null hypothesis is he's bullshitting and unless he gives compelling scholarly arguments or a very detailed reference (citation together with quotations or page number -- not a paper trail), then proving him wrong is almost certainly not going to be worth the time investment. They are not using random equations. They are basing their equations on data, which is what every sensible science must do. However, the observations made prior to the model being published is both being used explicitly, to determine empirical constants, and implicitly, to discard models with poor match. For this reason, backwards matching is at best very tenuous proof of the models' validity. Logic isn't your forte, as we see once again. I used the random equations thing as an EXAMPLE of the kind of thing that is equivalent to what you did.
On August 23 2013 05:55 Darkwhite wrote:As an example, I have explained how I can fit any dataset to any level of accuracy by doing a simple Fourier expansion. This is, of course, the extreme end of using only free variables. I am not suggesting that climate scientists are literally doing this. What I am saying is some free variable selection bias will still sneak in, by the two mechanisms explained in the above paragraph, and the best way to gauge the model independent of this is to focus on its forwards predictive accuracy. And because no half-competent climate scientist in the world would even dream of calling on this method, your point would appear to be pretty much irrelevant. Unless of course you can prove that they're less than half-competent. Which you can't.
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While I don't agree with Darkwhite, statistics require that you use prior data to test models and keep only those which correctly fit that historical data. I mean, you plug in variables for like atmospheric co2, solar radiation, wind patterns(?), I dunno, but it only makes sense to discard models which produce poor results and tweak/modify better models to be more accurate. I don't think this is wrong as this type of methodology is used in multiple other fields with high degrees of success; as long as unrealistic modifications aren't made to models they can be useful for predicting the future, but we must remember that "Essentially, all models are wrong, but some are useful."
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EPT
