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Post by socold on Jul 4, 2009 18:38:09 GMT
SoCold: I think you miss the point. No one denies that co2 is a greenhouse type of gas. And 30 years doesn't mean squat in climate unless you are talking about the quick changes that the Greenland ice core data shows. There have been numerous times in the past that the temp went up 2C in less than 30 years, and fell 2C in less than 30 years. And it can't be blamed on volcanoes etc. No one seems to really know the causes of those rapid swings. You miss the point. Skeptics argue for a low climate sensitivity which current physics doesn't support. They therefore are relying on discoveries about aerosols and the like in coming decades to all come in on the cooling side. I just don't think that's likely.
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Post by socold on Jul 4, 2009 18:48:36 GMT
Without the supposed cooling of aerosols...all we're stuck with is the rather mundane warming we find in observations. And the PipeLine The observations alone are inadequate to tell us a lot of things. We can't for example just look at the temperature record and figure out what caused the temperature changes over time. There has to be theory to explain it. Observed warming over the 20th century cannot be extrapolated simply because the forcings over the 20th century will not be the same as over this century. The high end estimates only occur if emissions increase substantially. I cannot see that happening, but then these are high end estimates. The mid range estimates are obviously more likely. It's too early to conclude we've seen a levelling off
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Post by socold on Jul 4, 2009 19:33:33 GMT
Thats incorrect. You forget the LIA. For there to be a LIA there had to be a warmer Halocene, both well accepted principles. Fact is its been this warm before and over a few centuries it descended into a cold spell. Thats well accepted. A much lower climate sensitivity rests on some new discovery happening. First of all you need the range of uncertainty in cloud feedbacks to fall at the low end, probably even further as even 2C warming per doubling of co2 is not compatible with what you are saying. As for LIA there's a graph on wikipedia of 1000 year temperature reconstructions and they all show a little ice age, but nothing to suggest we should still be coming out of it. In fact it looks like we were already out turn of 20th century. en.wikipedia.org/wiki/File:1000_Year_Temperature_Comparison.pngI am disputing the 20th century warming is a LIA recovery. I haven't seen evidence that the LIA was an event that required a 20th century recovery from. It's not clear that it has. Hansen argued, as many others will, that if the Earth starts absorbing slightly more energy, say 1 joule/second extra for each square meter of ocean, it will take a long time for the ocean to warm up fully, although most of the warming will happen quickly, the rest will follow later. In fact isn't this what LIA recovery requires too? I thought I've posted this before: www.aip.org/history/climate/co2.htmScientists have passed infrared radiation through gases in experimental conditions and measured the absorption. At different pressures, concentrations and temperatures. The military also took a lot of atmospheric measurements of IR propagation. The forcing from co2 is well pinned down thanks to lots of these experiments and observations, as well as the theory of how it absorbs in different conditions. The fall to minimum consitutes about 0.2wm-2 negative forcing. If that fall continued for 70 years, that would be a 2wm-2 negative forcing in total. If we use the mid climate sensitivity from models (3C per doubling of co2), we get 1.5C cooling. That's not really an explaination though. This is what you would get if recent warming is greater than the 20th century linear fit because of some recent forcing increasing. The problem is people trying to falsify the co2 forcing by picking trends too short. www.woodfortrees.org/plot/hadcrut3vgl/from:1970/plot/hadcrut3vgl/from:1970/mean:48
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Post by icefisher on Jul 4, 2009 21:45:06 GMT
A much lower climate sensitivity rests on some new discovery happening. First of all you need the range of uncertainty in cloud feedbacks to fall at the low end, probably even further as even 2C warming per doubling of co2 is not compatible with what you are saying. I don't need anything Socold. What you need is some actual warming. As for LIA there's a graph on wikipedia of 1000 year temperature reconstructions and they all show a little ice age, but nothing to suggest we should still be coming out of it. In fact it looks like we were already out turn of 20th century. I am not looking at anything that features bristlecone pines. Thats already been discredited. I am disputing the 20th century warming is a LIA recovery. I haven't seen evidence that the LIA was an event that required a 20th century recovery from. I assume you have a physical theory to support that like in the oceans can't possibly store energy that long right? Hansen argued, as many others will, that if the Earth starts absorbing slightly more energy, say 1 joule/second extra for each square meter of ocean, it will take a long time for the ocean to warm up fully, although most of the warming will happen quickly, the rest will follow later. In fact isn't this what LIA recovery requires too? I certainly wouldn't make a physical law out of that speculation. I would suggest it depends upon what is driving it. Scientists have passed infrared radiation through gases in experimental conditions and measured the absorption. At different pressures, concentrations and temperatures. The military also took a lot of atmospheric measurements of IR propagation. The forcing from co2 is well pinned down thanks to lots of these experiments and observations, as well as the theory of how it absorbs in different conditions. Stop being so pedantic. You become boring to correspond with when you continually fall back on rhetoric. We all know CO2 blocks IR. That is only half the story though. In order for CO2 to have the magnitude of effects you project it has to essentially transfer most of the heat it traps back to the surface. Where is the experiment that establishes that? The fall to minimum consitutes about 0.2wm-2 negative forcing. If that fall continued for 70 years, that would be a 2wm-2 negative forcing in total. If we use the mid climate sensitivity from models (3C per doubling of co2), we get 1.5C cooling. This is a non-argument, the same argument for which you cannot produce a single experiment showing it to be true. Oh I take that back you use TSI as the only source of cooling and from that calculate your sensitivities . . . .am I correct? Whats it now? 11 years? Wow! its already going to be 2020 before you can again make a claim about warming temperatures being evidence of CO2 forcing and thats only if it starts warming tomorrow.The problem is people trying to falsify the co2 forcing by picking trends too short. I want you to do something you obviously are not used to doing and that is pay very close attention to the nouns in what I am going to say. The last 11 years have not picked off any individual segment of the CO2 models and falsified it. What recent cooling has done though is falsified the models. And I say that on the basis that presumably these models are modeling the atmosphere. If they are not modeling the atmosphere they are not models of the atmosphere. Politically a decision was made to create models that don't hindcast, don't predict what the atmosphere is going to do tomorrow, do next week, next month, next year, next decade and I think soon the next generation; but instead purport to show what the atmosphere is going to do in a century. I would suggest if you can't predict what the atmosphere is doing in the short term you can't in the long term either and it seems the only experiment you have in mind is a 100 year experiment we won't have clue one as to whether its right or not for a 100 years. So as a model of the atmosphere they are clearly, permanently, and forever been falsified. As some speculative experiment that the real world is providing zero evidence for, like predicting martians landing in 2080 after calling out of their underground barracks; thats what the CO2 models do. What we are really dealing with here is tabloid science.
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Post by hunter on Jul 4, 2009 22:47:59 GMT
SoCold: I think you miss the point. No one denies that co2 is a greenhouse type of gas. And 30 years doesn't mean squat in climate unless you are talking about the quick changes that the Greenland ice core data shows. There have been numerous times in the past that the temp went up 2C in less than 30 years, and fell 2C in less than 30 years. And it can't be blamed on volcanoes etc. No one seems to really know the causes of those rapid swings. You miss the point. Skeptics argue for a low climate sensitivity which current physics doesn't support. They therefore are relying on discoveries about aerosols and the like in coming decades to all come in on the cooling side. I just don't think that's likely. Perhaps you miss the point? It is not physics that does not support low sensitivity. It is consensus climate science that does not support low sensitivity. And there is a big difference between the laws of physics and the climate theories which seek to apply those laws. There is good evidence, as well as qualified climate scientists, who think there is low sensitivity. They happen to not be very popular right now.
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Post by socold on Jul 4, 2009 22:49:46 GMT
If we throw out all the studies of the past 1000 years temperature we have nothing to go on. Without a temperature reconstruction clearly showing the little ice age and the periods around it, there is no basis to assume recent warming is a "recovery from little ice age". A much lower climate sensitivity rests on some new discovery happening. First of all you need the range of uncertainty in cloud feedbacks to fall at the low end, probably even further as even 2C warming per doubling of co2 is not compatible with what you are saying. I don't need anything Socold. What you need is some actual warming. We've had warming. Observations are consistent with that range of climate sensitivity. Warming of the atmosphere will cause more backradiation from co2 and water vapor. Near the surface it will be more water vapor. It's a number of experiments that establishes this, not a single experiment. They are fundamental experiments in climate, for example the spectral analysis of co2 in tube experiments will be just one part of the puzzle. Atmospheric observations of more backradiation during warmer days another. Basically everything you can find in a climate textbook has an origin in experimentation. You can trace it back to some set of experiments in the 50s, I am not a fountain of knowledge on the history of experiments in various physics fields though. I can no more list experiments that established the stefan-boltzmann law than I can list the experiments that established the Earth being 4.5 billion years old. But I can still reference both. There was no "political decision". There are experts trying to explain how components of the climate work the best they can. They put the lot together and see the emergent behavior and test it that the observed climate. This has been going on for decades. It's competative. A lot of teams trying to do it better. If they could predict a month out they would. But it's obvious that predicting the short term noise is not possible. The short term is affected by many more factors that are not important on the long term. Therefore the long term is easier to forecast.
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Post by socold on Jul 4, 2009 23:11:33 GMT
You miss the point. Skeptics argue for a low climate sensitivity which current physics doesn't support. They therefore are relying on discoveries about aerosols and the like in coming decades to all come in on the cooling side. I just don't think that's likely. Perhaps you miss the point? It is not physics that does not support low sensitivity. It is consensus climate science that does not support low sensitivity. The consensus is based on the most vigorous application of the physics. Then why don't they point out the area of the physics which the climate models are getting wrong? Why don't they help make a better model? It's basically a claim that the physics is wrong, but we don't yet know why. Great, but constrast that with decades of climate modelling which has been giving a consistent result that climate sensitivity is not low. If it could be shown that the models could be altered in some way to show a lower climate sensitivity, that would be a great argument. But noone has managed to do this. Some models show lower sensitivity than others, but none of them show anything as low as the skeptics are suggesting. I am not accusing them of deliberately not doing so, they can't do so because they are largely speculating. Nothing wrong with that, but they have no calculated numbers, they are throwing out an idea that X will reduce warming. But they don't know how X can work, only that maybe it can. If they knew how they could suggest how the models should be corrected. And then after the correction we could see what the models show and whether they do show a low climate sensitivity. When it's so hard to get a low climate sensitivity from physics, perhaps that's just because a low climate sensitivity is not possible.
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Post by icefisher on Jul 5, 2009 1:58:13 GMT
I don't need anything Socold. What you need is some actual warming. We've had warming. Observations are consistent with that range of climate sensitivity. Thats the point they are not consistent. We had virtually an identical warming from 1910 to 1940 when CO2 was much lower. Atmospheric observations of more backradiation during warmer days another. How about a link to this on Socold! Basically everything you can find in a climate textbook has an origin in experimentation. You can trace it back to some set of experiments in the 50s, I am not a fountain of knowledge on the history of experiments in various physics fields though. I can no more list experiments that established the stefan-boltzmann law than I can list the experiments that established the Earth being 4.5 billion years old. But I can still reference both. Pray tell how you can reference a study you can't list. There was no "political decision". There are experts trying to explain how components of the climate work the best they can. They put the lot together and see the emergent behavior and test it that the observed climate. This has been going on for decades. It's competative. A lot of teams trying to do it better. If they could predict a month out they would. But it's obvious that predicting the short term noise is not possible. Be advised the decision to fund a study that essentially hypothesizes beyond all that noise and just ignores it as noise and pretends it has no long term effect is in fact nothing more than a policy (political) decision. The short term is affected by many more factors that are not important on the long term. Therefore the long term is easier to forecast. You say! LOL! But be advised thats an experiment that we will not know the results of for some time to come. The nearest thing I can think its akin to is some guy totally enthused by heavier than air flight standing on top of the barn peak about to leap and thinking about how he will store the plan after he lands, suggesting that he need not worry about the landing.
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Post by poitsplace on Jul 5, 2009 2:16:34 GMT
The high end estimates only occur if emissions increase substantially. I cannot see that happening, but then these are high end estimates. The mid range estimates are obviously more likely. Technically the "mid range" estimate is in fact what I showed but...it's OBVIOUSLY too high [/quote] Ok, perhaps simple concepts just don't manage to slip past all the brainwashing but...the COOLING period would need a steeper slope than the WARMING period that just ended. Basically to fit the warming/cooling period the slope of the warm period that just ended would need to have been about 50% more pronounced. Can you get what I'm saying here? The climate was essentially at top speed. It was on a natural warming trend AND we were dumping CO2 into the air. Now you're suggesting that the same climate is somehow going to lurch into an even higher speed while in a cooler mode but without additional warming. The ONLY thing that makes sense since CO2's absorption is logarithmic but it's increases are linear is to assume a linear trend or lower. Previously it's been ASSUMED that the warming was covered by aerosols but new studies have found that in the arctic especially, the aerosols would have had an extremely powerful warming affect (and a LOT of the observed warming is from those regions). And while the hypothesis that CO2 causes such incredible warming has hit a huge snag in recent cooling...the hypothesis that a large part of the warming was from natural cycles has hit an important milestone. The latter correctly predicted the shift of the ocean currents and drop in temperature. The excuse, "it's just weather" simply doesn't cut it when you're talking about 12 years of no warming on a .4C/decade "cooling" trend and a .6C/decade warming trend. To fit the pattern at all the cooling period needs to have a more shallow temperature rise than the warming period. The highest projection that meets that criteria is BELOW 2C (and even that would mean the next warming trend would need to be .5C/decade just to catch up). Why on earth would a skeptic EVER think that or the higher "mid-range" estimates were reasonable given the complete lack of evidence for it?
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Post by socold on Jul 5, 2009 11:09:12 GMT
We've had warming. Observations are consistent with that range of climate sensitivity. Thats the point they are not consistent. We had virtually an identical warming from 1910 to 1940 when CO2 was much lower. And that falsifiesa high climate sensitivity? No eg www.esrl.noaa.gov/gmd/grad/brwmain.htmlI can't reference the Earth being 4.5 billion years old or the radiodating methods used to determine it without knowing the precise study (or studies) that established this? No that's crazy talk. Why don't weather organizations make predictions 6 months out for where storms will happen? Do you think that's a political decision too? I think it's because it's very hard, actually impossible to do that kind of forecast. It's nigh impossible to predict ENSO patterns 10 years in advance, but you can predict the response to a strong forcing over many decades. It's ongoing, we have decades of past data. It's not as if it didn't warm during the last 30 years. We can see the trend over that time period breaks through the noise, ie the overall warming is greater than the year to year variation from the noise.
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Post by socold on Jul 5, 2009 11:47:59 GMT
The high end estimates only occur if emissions increase substantially. I cannot see that happening, but then these are high end estimates. The mid range estimates are obviously more likely. Technically the "mid range" estimate is in fact what I showed but...it's OBVIOUSLY too high 3C is the A1B, A2 scenarios which are two of the highest. Both see emissions continue to rise for another 30 years, A1B continues upwards till 2100 by when emissions are over 3 times greater than they are today, which I find highly unlikely. A2 emissions go roughly flat 2030-2100. Again I find that unlikely. More likely emissions will rise for a while longer but then fall as in A1T and B1, with temperature rise about 2-2.5C by 2100. Nope, the addition on the below graphic has a less steep cooling period, but shows every period increasing in slope as time progresses. The overall trend is slightly exponential, but not much and only because under this projection GHG emissions treble by 2100. Not top speed because according to A2 and A1B emissions will close to double by 2030, and going by the oscillation argument we would then have a natural warming trend AND even more co2 forcing than the 1970-2000 period. The above graphic addition does show a roughly linear trend from 1970 to 2100. Of course this rate of growth is a rapid acceleration from the 20th century pattern, but then GHG did start ramping up mid 20th century so a sudden change in behavior at this point could be expected. There are many factors of uncertainty, one is the feedbacks, another is aerosols. There are also issues with the climate response, how long does it take a body of water the size of the ocean to warm up fully from a 1wm-2 forcing. There are warming and cooling effects from aerosols. The models are tested against all this to produce the ranges of uncertainty we see. However they are still pointing at significant warming, even if we take the mid range projections. There hasn't been 12 years of no warming. There has been perhaps 6. But then that 6 year period starts with a strong el nino and solar maximum and ends with a strong la nina and the current solar minimum. So what a bad 6 years to pick to make a point about weather not affecting the trend. How do you know the cooling since 2003 wasn't simply due to lowering ENSO and lowing solar cycle and nothing else? Why invoke any mystery natural cycles when the drop can be explained by these two phenomenon alone? If the drop is caused by only the ENSO drop and the solar drop, then when ENSO increases (as it is doing now) and solar cycle 24 ramps up we will return to the 2003 levels and higher. We can even do some maths now. If the current solar minimum has dropped global temp down 0.1C, then we can expect about 0.1C warming in coming years. If ENSO has dropped it 0.2C, we can expect 0.2C warming in coming years. 0.1 + 0.2 = 0.3C above today and on track with warming. We can pose this question in a few years time.
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Post by poitsplace on Jul 5, 2009 19:02:29 GMT
So again from a logarithmic increase by CO2, ice-albedo feedback rapidly decreasing to zero and at the very most a linear increase in water vapor feedback (if it's not actually negative) and exponentially increasing output with temperature (a strong negative feedback)...you expect an exponential increase in temperature? I hate to break this to you but mathematically we can consider that entirely falsified. Anything in the models is due to parametrization allowing the models to do things that aren't possible in reality.
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Post by socold on Jul 5, 2009 19:52:45 GMT
So again from a logarithmic increase by CO2, ice-albedo feedback rapidly decreasing to zero and at the very most a linear increase in water vapor feedback (if it's not actually negative) and exponentially increasing output with temperature (a strong negative feedback)...you expect an exponential increase in temperature? I hate to break this to you but mathematically we can consider that entirely falsified. Anything in the models is due to parametrization allowing the models to do things that aren't possible in reality. No I don't expect this, the high end model projections show basically a linear warming since the 70s. I can't break that down into components myself, but I suspect it has something to do with co2 levels increasing exponentially.
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Post by icefisher on Jul 5, 2009 21:02:27 GMT
Thats the point they are not consistent. We had virtually an identical warming from 1910 to 1940 when CO2 was much lower. And that falsifiesa high climate sensitivity? No I would suggest you didn't listen, or if you did it hit a void between the ears and passed straight through. I can't reference the Earth being 4.5 billion years old or the radiodating methods used to determine it without knowing the precise study (or studies) that established this? I don't think we are talking about precise references here. Sounds like another of your strawmen. Either you are aware of how this was established or you are ignorant of it. Can't be both. Myself I don't dispute anybody's estimate of the age of the earth. I have no reason to. Perhaps though if somebody starts talking about taxing me on it, I am sure going to find out though and I am not going to run around trying to sell it to somebody else without knowing it for sure either. When you suggest its OK to sell it without knowing it, that must mean either you have no sense of ethics or you have no idea where the line is between fact in fiction inside of your head. No that's crazy talk. Why don't weather organizations make predictions 6 months out for where storms will happen? Do you think that's a political decision too? I think it's because it's very hard, actually impossible to do that kind of forecast. I would suggest that the world of physics isn't quite prepared for the real world. Apparently they have difficulty distinguishing between a radiocarbon experiment that skips over 4.4 billion years of history and a model that skips over every variation they have no clue about what drives it, calls it noise, and applies an overly simple explanation to what is an incredibly complex process. That might be a good use of Occam's Razor but Occam's Razor should not be used for policy decisions when those policy decisions limit people's freedoms. To many people died for those freedoms to sell them off so cheaply. It's nigh impossible to predict ENSO patterns 10 years in advance, but you can predict the response to a strong forcing over many decades. No you cannot. You need to understand how the system works, otherwise feedbacks can change everything assuming you have correctly allocated the forcing in the first place. You say! LOL! But be advised thats an experiment that we will not know the results of for some time to come. It's ongoing, we have decades of past data. It's not as if it didn't warm during the last 30 years. We can see the trend over that time period breaks through the noise, ie the overall warming is greater than the year to year variation from the noise. You can't say that unless you understand other changes of greater or near equal volumes. You failed to respond to the 1910 to 1940 question and instead attempted to erect a strawman there instead. The AGW alarmists are their own undoing. For the most part they have believed they can get away with shoddy work and try to pass it off as unbiased. They have been doing it for years using foundation money and they think nobody can challenge them. I think they have a rude awakening awaiting them. They may be their own worst enemy.
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Post by socold on Jul 5, 2009 21:39:53 GMT
I don't think we are talking about precise references here. Sounds like another of your strawmen. I am unaware of all the precise experiments on co2 spectrum in labs. I am unaware of all the precise experiments measuring IR propagation in the atmosphere. I am unaware of the precise experiments measuring convection and other properties of the atmosphere at various locations. Yet I know these have been done because a) It would be absurd to imagine noone has experimented on these things over the entire 20th century b) It would be absurd to imagine a hoax by which all the data is false and not based on underlying experiments c) There are research areas and applications independant of climate that rely on the same data It's all these experiments that come together to form the backbone of the models. All the physics and absorption spectrums in the textbooks come originally from experiments. Experiments that perhaps went on to form laws. Stefan-boltzmann law for example wasn't made up on the spot, it was surerly derived from experimentation although again I don't know the precise experiments or how they were done. How does convection work? How do different layers of the atmosphere emit radiation? These kind of questions have answers and experiments behind them. People don't just sit idle for 50 years without quantifying these things and explaining them with physical laws. This stuff is what goes into climate models. They don't invent how convection works, they take result derived through experiment in the past. I read summaries of it like this: www.aip.org/history/climate/co2.htm which lays out enough summary for me to get the gist of how it's established. I have no reason to follow all the references down to the precise experiments, but if I wanted to I know I could. The references in papers form a chronological tree. Each paper contains dozens of references to previous papers, which in turn contain dozens of references to even earlier ones, etc. I don't know how deep it gets, probably very deep, but the more fundamental experiments will have been done long ago and lie far down the chain. So it is available for you to search, it's just a very long process, but then this is the long process any scientific expert in a subject will have to go through to delve through all the past papers in their field. In fact they can't use radiocarbon techniques to date the Earth because the halflife of carbon is too short to measure beyond something like 20,000 years. Although I have read that in special lab conditions they can push it back 50,000 years. Again though I know no precise experiments on this, I simply know the summray I have read coupled with a good feeling that I could follow all the references back to the source if I wanted to (although the initial source in this case would involve having to find a summary that references a few papers). As for climate models, they are built from the ground up taking the equations, data and laws which have been derived from experiment and observation to describe the behavior of sea ice, convection, radiation, etc. These components are then put together to run and see what the emergent behavior is. The actual workings of the climate model are too complex for anyone to understand, you have all these components simultaneously interacting, just as in the real climate, and it's hard to see what is causing what. It's hard for example to tell why one model differs from another in some aspect. It's the same priciple that I don't need to forecast the precise position of every raindrop during a storm to forecast the average rainfall. It's about forecasting the forest rather than the trees. The broader, longer forcast should be easier. And there is good reason to think this is the case, because while the models disagree a lot on short time scales, they are very consistent at long timescales. It's almost as if there is some fundamental difficulty with getting a model to show less than 2C warming from a doubling of co2. I can't even recall that now. If you want me to address something specifically the best bet is to only post that one thing. If you post dozens of things the chances are one or two will slip through the net. I just await someone pointing out where the models are wrong and showing a different sensitivity from a model if that thing is changed. The best bet to abolish AGW afterall is to change the forecast charts in the next IPCC report, and to do that requires some models to at least show a low climate sensitivity to show that it is plausible.
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