It’s one of them conspiracies.
An anecdote about cherry-picking: My wife and I were watching a show about Millikan’s experiment that measured the charge of the electron. The program showed his notebooks, which showed numerous samples he had crossed out. I asked, “How did he get a Nobel when he threw out the results he didn’t like?”
“He got the Nobel because he knew which results should be thrown out.”
One difference between an expert and and an amateur is the ability to recognize garbage.
Just to counter my own cite above, and thus illustrate why I’m on the fence, another study says 2007 has indeed been warmer.
Sounds really evasive, but okay.
Skepticism is fine - the basis of science is skepticism. Skepticism, however, implies that should evidence be presented, you could be convinced. Later in your reply you specifically dismiss all the evidence without any reason - that isn’t skepticism, that’s ignorance.
Because of skepticism. One proof of anthropogenic global warming isn’t enough.
Yet, you are not debating the substantiative issues and dismissing the IPCC data on an unknown basis.
Your actions are increasingly divergent from your stated intentions.
I misunderstood you because sensitivity is a specifically defined term in climatology - a 1.1-2.9[sup]o[/sup]C range is insensitive because the variability between runs (1.3[sup]o[/sup]C) is small and a 2.4-6.4[sup]o[/sup]C range is sensitive because the variability between runs (4.0[sup]o[/sup]C) is large.
Your definition makes no sense. I have a sneaking suspicion that you really have no clue what an SRES scenario is, so I’m going to start from ground zero. Out of the thousands of simulations run, each has a different set of economic parameters - population growth, GDP growth, rate of inventing clean technology, etc. Out of all of these, the IPCC grouped the ones that were closest in economic assumption and gave them the 6 SRES categories with the same economic parameters (although each of the individual runs within a group has different climatological parameters). The sensitivity (by the proper definition) of each SRES scenario indicates how dependent the climatological result is on the minor differences in climatological parameters in the same SRES. This gives generally small results: +/- 0.5-1.0[sup]o[/sup]C. The difference between SRES scenarios, however, is much larger: +/- 1.0-3.0[sup]o[/sup]C. This indicates that climate models are much more sensitive to differences in economic parameters between different SRES.
Technological singularity or not, it’s impossible to compare two values unless you actually know both values. You have shown a profound lack of knowledge about what the climatological score is.
On what basis do you contest the instrumental temperature record?
And since I am now openly doubting whether you’ve even seen the evidence before dismissing it, I am citing exactly which figures and chapters to read so that you have no more excuses.
IPCC 3AR WG1: Chpater 2.2, esp. Figure 2-7.
NAS CCR: Chapter 5.
IPCC 4AR WG1: Chapter 1, esp. Figure 1.3.
Well, scientists do.
IPCC 3AR WG1: Chapter 3.4, esp. Figure 3-3.
NAS CCR: Chapter 3.
IPCC 4AR WG1: Chapter 2.3, esp. Figure 2.3, and take special note of Figure 2.3(b) and learn why [sup]13[/sup]C/[sup]12[/sup]C is super-important in determining how much CO[sub]2[/sub] comes from fossil fuels.
On what basis? Scientists disagree with you.
Competency:
IPCC 3AR WG1: Chapter 6.13, esp. Figure 6-6.
NAS CCR: Chapter 5.
IPCC 4AR WG1: Chapter 2.1, esp. Figure FAQ 2.1
Necessity:
IPCC 3AR WG1: Chapter 12.2, esp. Figure 12-7.
NAS CCR: Chapter 5.
IPCC 4AR WG1: Chapter 9, esp. Figure 9.5.
On what basis? Scientists disagree with you.
IPCC 3AR WG2: Chapter 2.6, esp. Figure SPM-1.
IPCC 4AR WG2: Summary for Policymakers, Figure SPM-2.
The amount of hand-holding I have to do to you is irritating. If you look at the SRES scenarios, it is quite possible to stop CO[sub]2[/sub] levels from increasing.
For someone who bills himself as having an open mind and wants to discuss the nitty-gritty of global warming, you are certainly disappointing.
Yet you plan as such, do you not? Or do you have retirement money sitting in an account with zero expectation of growth?
This is answered in my posts to brazil84, but I’ll summarize.
(1) The amount that humans are “pushing” the temperature higher is currently 12x higher than the amount that natural forces are “pushing” (radiative forcing).
(2) Historically, all of the data from 1900-1950 can be explained without invoking any human causes. However, the data from 1950-2000 cannot; when you add in the expected human warming from (1), the models and observations match exactly.
For now, yes, but CO[sub]2[/sub] emissions will continue to rise, and we are well out of the Little Ice Age now. We’re actually at or above the much-touted Medieval Warm Period, a period of unusual warmth.
However, as I noted to jshore a few posts up from this quote, the rate at which temperature changes is going to impact us a lot more than the absolute temperature. We (as a species and as modern, Western civilization) can probably adapt to large temperature changes, if we have enough time.
For scientists, you’re right. 3 good papers is worth more than 650 bad papers, and for people who are knowledgeable in a subject, evidence, not popularity, rules. Not many scientists dismiss that there are minor controversies.
However, in terms of moving the debate into a public forum, given 650 papers on one side and 3 papers on the other, which side should dictate public policy? This is a little different now. How much dissent are we willing to allow to hold up action?
As examples, there are scientific papers and credible scientists that claim HIV is not the cause of AIDS; that smoking is harmless; that the World Trade Center towers in New York City could not have collapsed as a result of passenger jets. Should we stop HIV vaccine development until we’re “sure”? Should we drop anti-smoking efforts because there is “scientific disagreement”? Should we hold off on assigning blame to terrorists or “teach the controversy” to be fair to both sides?
I argue no to all of these - there is enough evidence to warrant action. Perhaps the American judicial rule of “beyond a reasonable doubt” applies here.
Global warming, admittedly, is a topic much more complex than these - the consequences of inaction and the costs of action are much more nebulous. That’s why it’s critical for people to stop getting hung up on the simple, nearly-unanimous topics such as “Is the Earth warming?” and “Is it our fault?” and move on to “What can we do, and will it be worth doing?”
Is it not true that the models are specifically tuned to fit the past data? And in the past models which have extrapolated into the now present have been proved wrong?
You’re assuming those 650 papers are good. Many are based on models, which I, for one, discredit. Others, given high publicity, like Mann’s hockey-stick, have been otherwise discredited.
No, because the examples you give are falsifiable. And have been proven false. Current climate change theories are not falsifiable. We’ve had ice ages with higher CO2 levels. BTW I’m including non-CO2 climate change theories - I asked about one of the solar theories a while back.
This is the big problem. There is actually no evidence whatsoever that our CO2 emissions are anything to do with global warming. Sure the temperature increase is coincident with increased CO2 emissions, but it’s also coincident with the solar cycle - and some say that’s a better longer-term fit. But correlation is not causation. Maybe they’re both right; maybe they’re both wrong. I don’t know, but I’m thoroughly skeptical of something that has no actual evidence.
So I’ll continue to question.
Of course it’s true that models are tuned to past conditions. How else could you calibrate a model with the degree of complexity of a GCM? How could you calibrate any model without comparing it to known conditions?
There are two important steps to using a model: calibration and validation. Calibration involves setting all the parameters of a model so that it accurately simulates a known condition, given the correct initial conditions and boundaries. you simply can’t calibrate a model without specifically tuning it to past data - there’s no other way to know whether it can do what you want it to do. Model validation involves taking the calibrated model, inputting a set of initial conditions, and simulating another known condition. If the model simulation predicts the known condition within the acceptable range of error (which varies depending on the field and objective of the model), it is considered “validated.” There are certainly conditions associated with the validation, and a discussion those conditions is generally included in scientific publications.
In the past, models have had varying degrees of success. It’s certainly true that some models have failed to accurately simulate the climate, and those models are either revised or discarded. It’s also true that some models have accurately simulated parts of the climate system and the Earth’s response to various driving conditions. These models, too, are continually revised to improve the precision and accuracy of the simulations.
If you’re looking for a single model that has accurately simulated every component of the climate system, you’re not going to find it. Ever, probably. But various models do accurately simulate different components, and the bulk of the validated models generally converge on similar results when run with similar conditions (a doubling of pre-industrial CO2 concentration, for example).
Do you use public water supplies? They’re based on population models, as well as hydrologic models that predict the impacts of withdrawal of water from aquifers and streams. Roadways are designed based on models that predict population growth and distribution. Hell, stores are located based on those population models, with economic factors thrown in that make them even more complex. If you reject every conclusion that’s based on modeling, you’re left with an incredibly simplistic view of life, and a fairly limited range of options.
And Mann’s hockey stick hasn’t been discredited. Rather than repeat previously posted material, I’ll link to posts in brazil’s earlier thread by Gigobuster and jshore.
Cite for an ice age with elevated CO2 concentrations?
What solar theories are you asking about? The orbital cycles that affect the amount of solar radiation reaching the Earth have periodicities far too long (19,000 years is the shortest) to produce the effects we’ve seen over the last century, and the current estimates of solar forcing to changes in the sun itself put the temperature change over the last 100 years at about 0.2 degrees - 20% of the observed change. Is there another solar theory that you’re advancing?
This is just plain wrong, on two fronts. First, there’s your claim that there’s no evidence that our CO2 don’t affect the Earth’s climate. This is simply mind boggling. The link between CO2 and temperature on Earth goes back at least hundreds of millions of years. In the mid-cretaceous period (100 million years ago), the average temperatures in the tropics were a few degrees warmer than they are today, while the poles were 20-40 degrees warmer - during this period, CO2 concentrations are estimated at 4-10 times today’s numbers. On the flip side, CO2 concentrations during the last glaciation were significantly lower than todays values - roughly 200 ppm compared to pre-industrial values of 280 ppm and a current concentration around 380 ppm. The correlation between CO2 and temperature is clear, and the driving mechanisms of greenhouse gases and the feedback loops they cause have been explored for decades. With this correltation and the enormous increase in atmospheric CO2 over the industrial age, how can you defend your statement?
Aside from that, you’re also wrong about the coincidence of temperature increases with solar cycles. The recent temperature changes (over the last 100 years) diverge from the changes that would be expected from the sum of the solar
cycles. Can you provide a cite to a peer-reviewed journal that claims there’s a better fit between solar cycles and temperature than there is between CO2 and temperature?
Are you questioning, or are you flat out saying “that ain’t true,” and refusing to listen to any arguments to the contrary?
Yes, that is not true. As a matter of fact, the IPCC presents many such models to show that minus anthropogenic greenhouse gases, it’s impossible to fit the past data.
This is an unanswerable question.
(a) I’m sure that you could dig up some past model which would be proved wrong when extrapolated to now, but that doesn’t answer the question about whether the best models have been proved wrong.
(b) In terms of climate change, there hasn’t been enough time to test any model beyond statistical noise, especially the latest, and arguably best, models.
(c) If a particular model were outside its predicted range, it still wouldn’t answer the question of whether the model is valid. After all, and I will assume you now agree that economic models of the stock markets are still widely used and accepted, we still use plenty of models whose short-term predictions have been torn to shreds.
Why wouldn’t you? Are you qualified to review climatology papers?
You will note that only one half of one argument rests on models at all, and no arguments on a hockey stick. I’ve specifically excluded any mention of proxy temperature data to avoid the hockey stick argument (this upon request of brazil84 from the hockey stick threads).
Absolutely wrong. That HIV causes AIDS has never been proven - only a strong (and not absolute) correlation has been shown. Most people who have AIDS have anti-HIV antibodies - but not all. Most people who are HIV(+) have or get AIDS - but not all. If we demand the same level of proof that climate change deniers demand of global warming, the only way to “prove” HIV causes AIDS would be to intentionally inject a control and experimental group with a placebo or HIV, respectively - something clearly unethical.
Correlation does not imply causation, but correlation strongly suggests causation if no other explanation can adequately explain the observations and the correlator is both competent and necessary.
Are there anomalies in the HIV/AIDS correlation? Yes; some answered, some unanswered (as listed above). Yet, we cannot find anything else that would adequately explain why 99% of the people who get HIV get AIDS and 99% of the people who have AIDS have HIV. Unless we find something, we can be strongly confident that HIV causes AIDS.
Are there anomalies in the smoking/cancer correlation? Yes; everyone has that obese uncle who chain-smoked for 80 years and finally died in a traffic accident at 93. Yet, when we correct for lifestyle factors, we cannot find anything else that would adequately explain why smokers get so much more lung cancer than non-smokers, and why such a risk increases with dose. Unless we find something else, we can be strongly confident that smoking causes lung cancer.
Are there anomalies in the planes/WTC correlation? Yes; it’s unusual that the missing black boxes were never found. Yes; there were conflicting reports from different government agencies. Yes; a lot of external evidence was seized by the FBI and never declassified. Yes; the temperature of the flame might only have been hot enough to weaken, not melt, the steel beams. Yet, we cannot find anything else that would adequately explain why the towers collapsed after getting hit by planes. Unless we find something else (and Lord knows people have tried), we can be strongly confident that the plane impacts caused the towers to fall.
Likewise, are there anomalies in the GHG/AGW correlation? Yes; in the Milankovitch cycles CO[sub]2[/sub] seems to lag, not lead, temperature increases (explanations available). Yes; there are unanswered questions about solar flux verses solar dimming. Yes; many of the early temperature measurements were taken in urban heat islands (which actually works in favor of the AGW argument because it would increase later temperature changes which are more attributable to human activity). Despite all of this, we cannot find anything else which would adequately explain why the Earth is warming to this degree. Unless there are factors which are both competent and necessary that have not been addressed (and the IPCC has addressed many), we can be strongly confident that anthropogenic emissions have caused global warming.
Sure it’s falsifiable - return to pre-Industrial times, see if temperatures level off, and then restart industry to see whether temperatures keep climbing.
Definitely false in the past 400,000 years. The Vostok ice core shows the last Milankovich cycles to oscillate between 200 ppm and 300 ppm CO[sub]2[/sub] - current levels are 380 ppm. Probably false in the past 50,000,000 years - isotopic measurements in rock sediment shows a big decrease from the Jurassic, but has been low since then. You need to go back a good 100,000,000 years to find a time when we had demonstrably higher CO[sub]2[/sub] levels than we do now. Modern humans (25,000 years old?) have definitely never seen this much CO[sub]2[/sub] in the air.
I’m not entirely sure which solar cycle you’re talking about - there are many, and the shortest of which is 11 years. But in any case this is a question with a definite answer: radiative forcing. We know exactly how much more sunlight we’re seeing. It’s quantified and in the IPCC diagrams. Likewise, we know how much CO[sub]2[/sub] is forcing. It’s quantified and in the IPCC diagrams. The net anthropogenic forcing is 12x higher than the natural forcing - yes, both are pushing us warmer, but one is pushing 12x harder.
Questioning is fine, so long as you don’t shut your eyes to the evidence. I’ve taken a decent chunk of time to point you and brazil84 to the exact chapters in the IPCC reports and NAS report so that you can see (a) the evidence, and (b) whether the evidence supports their conclusions.
Then why did he have to publish a corrigendum (pdf) which admitted that it failed rigorous statistical validation and used invalid proxies (amongst other issues)?
Earth’s distant past. Hundreds of millions of years ago.
Sunspots is one. The Maunder minimum is coincident with the Little Ice Age. A clip from an article by Dr David Whitehouse:
Now, I find this interesting, but not compelling. Interesting because it provides a reason for why we came out of the Medieval Warm Period and the Little Ice Age. But one reason I don’t find it compelling is that I’ve read elsewhere (sorry, it was in a book long ago, so no link) that the MWP may have been ended by a massive volcanic eruption. Another is that it’s not a perfect fit. A third is this pdf (which I found hard going) which only shows a suggestion (due to insufficient data) of a correllation between the Maunder Minimum and the Wolf and Spoerer Minima. And, of course, the Little Ice Age lasted over 300 years, vastly longer than any of the aforementioned minima.
BTW if anthropogenic CO2 is responsible for GW, but only in the last 100 years or so, what did cause the Earth to come out of the Little Ice Age?
I’m not talking of the Milankovich cycles.
But I didn’t say that. I said that there’s no evidence that the CO2 we’ve produced is responsible for the warming we’ve seen. That’s much more specific.
I’m questioning: the AGW movement is based on the link between human-produced CO2 and global warming, but that link simply has not been shown. I personally questioned Lord May, a past President of the Royal Society, on this last year, after he’d given a speech which touched on Global Warming, and he was unable to gainsay me. Of one thing I am sure: the record shows that the only constant is change. To assert that the current change is down to us is bold. Not necessarily wrong, but bold nonetheless.
I’ll just throw in a couple additional comments.
Let me try to bridge the gap between these answers. Climate models are not statistical models or models with a lot of fitting parameters. They are mechanistic models based on the physical processes in the atmosphere, oceans, etc. That said, it is not possible to represent all such processes from first principles, e.g., things with clouds that occur on scales smaller than the model resolution so there are some parameterizations for things like these.
However, it is important to understand that such parameters are generally adjusted to get basic features of the process in question correct or, in a few cases, to get some basic climatological things correct. However, there are many, many more degrees of freedom than there are parameters…so, the models cannot in any way be “tuned” to fit the massive volume of available data. Furthermore, none of this sort of parameter tuning will really be able to tune (say) the time-dependence of the global temperature record.
There is a famous aphorism in physics due to somebody or other that says “Give me four parameters and I can fit an elephant. Give me five and I can make it wag its tail.” (You can also find versions on the web with the numbers 3 and 4 or the numbers 5 and 6.) At any rate, it is true that if we wrote up some simple functional dependence T = f(t) where T is global temperature and t is time and chose the function f(t) well with several free parameters, we could probably do a decent job in fitting the instrumental temperature record. However, this is in no way what the models are actually doing.
If one thinks they are in some convoluted way doing this, then there would be an easy way to demonstrate this: Namely, you could take one of the climate models (at least one if not several are publicly available) and “tune” the parameters so that the global temperature vs. time is well-fit without having the greenhouse gas forcing in the model, i.e., simply using the natural forcings. I think the fact that this has not been done speaks volumes.
Worse yet, the time-dependence isn’t right. I.e., there is no way to explain the warming that started about 1970 and has continued since then.
A couple of nitpicks:
(1) The ice core data for CO[sub]2[/sub] now goes back 650,000 years (published) and apparently 800,000 years (unpublished but presented at the AGU meeting).
(2) I think your numbers for when CO[sub]2[/sub] was likely higher than now are a little off. A graph in the IPCC third assessment report that showed CO[sub]2[/sub] over different timescales suggests that it gets above current levels once you go back about 23 million years ago. Of course, whether it was 23 million years ago, 50 million years ago, or 100 millions years ago when it was last higher is not too relevant. All of those numbers are well-before homo sapiens were around (or anything particularly close to homo sapiens).
The corrigendum says nothing of the sort. It mainly just notes mistakes that were made in recording which data was used in the Supplementary Information published online along with the paper. There is hardly a paper published that does not contain some sort of typographical error or incorrect or incomplete description of data used, or something of the sort. The concluding sentence of that corrigendum says: “None of these errors affect our previously published results.”
There are a few points to make here:
(1) It is very hard to get accurate measurements of CO2 levels at the necessary resolution going back that far. As aptronym noted, excellent CO2 data is available as long as the ice core data go back (now 800,000 years). Beyond that, the available data are much less time-resolved and much less certain.
(2) Of course, noone is claiming that CO2 is the only factor that affects climate. There are many other factors, particularly on geological timescales. For example, I believe that the sun has generally been trending brighter over time on the billion year timescale. Also, continents and mountain ranges were in different locations tens or hundreds of millions of years ago, which can have profound climatological effects. While it is interesting to study the various factors that affected climate on these timescales, it is in many respects much harder than looking over the timescale of the last 800,000 years for which very good data is available and for which most of these geological factors haven’t changed very significantly.
(3) Here is an article by two people who are experts in paleoclimatology. Note that their conclusion is that, if anything, climate models may be underestimating the sensitivity of the climate to perturbing forcings, such as the known forcing that we are producing by the added greenhouse gases.
Noone disagrees that solar activity affects the climate. However, the question is whether the current warming can be explained by solar activity, and the evidence overwhelmingly argues that it can’t be.
As for sunspots in particular, there was a famous paper from the early 1990s argued for a correlation between sunspot cycle length and global temperature…and was (and still is) popular in skeptic circles. However, more recently, one of co-authors has revisited the more recent data and has found that the correlation breaks down dramatically since ~1980, with the climate continuing to warm while the sunspot cycle length remains flat. (There have also been papers, e.g., here, that have shown that the correlation was never really as good as it was claimed to be in the first place.)
It is not an assertion that has been arrived at lightly. The first calculations of the warming effect due to a hypothetical doubling of CO2 in the atmosphere go back over 100 years to Arrhenius. When James Hansen first announced to the world in the late 1980s that the effects of greenhouse gases had emerged from the noise, the scientific community as a whole was initially skeptical. However, 20 more years and lots more data, modeling, and other studies have convinced nearly all of them that this is in fact correct. The story of the discovery of AGW is an example of a hypothesis that spent a lot of time being pretty much ignored or dismissed by the scientific community. It is only once the evidence became more and more clear that they were won over.
Did you read your cite? Mann, et al. published more complete data sets, corrected some errors in their original work, and provided a fuller description of their methodology. Did you happen to catch the last sentence of the corrigendum? “None of these errors affect our previously published results.”
But don’t take their word for it - check with the U.S. National Academy of Sciences. The publication of a corrigendum doesn’t necessarily invalidate a paper - it can, but it depends on the contents of the corrigendum and the other available data.
There’s nothing in that cite about the CO2 concentration during “Snowball Earth” - just an overview of the (controversial) hypothesis. Do you have any cite for the atmospheric CO2 concentration that long ago? Preferably one that’s been peer-reviewed, and isn’t found on the website of a telephone psychic.
Is there evidence of greater solar radiation over the last century? Everything I’ve seen attributes about 0.2 degrees to increased insolation; that leaves 0.4 to 0.6 degrees (depending on your estimate) of warming unexplained.
The article you linked to discusses the influence of solar radiation on production of the Cl-36 isotope. The upshot is that the two appeared to be linked, but local variations in the Cl-36 concentrations during periods of relatively constant insolation show that other factors impact this concentration. The article doesn’t link the Cl-36 to climate effects, and doesn’t discuss Cl-36 trends outside of the ones that it links with the sunspot minima. I’m not sure what role you think it plays in this discussion.
There are any number of feedback loops that can magnify the effects of small changes. Changing temperatures can cause changes in atmospheric circulation, which leads to differences in global heat transport. Since the Little Ice Age appears to be more a regional phenomenon than a global one (records from the northern hemisphere show a pronounced effects, without analogous signals in Antarctic ice cores), the regional temperature changes could certainly have induced circulation shifts. The sunspot activity may well have contributed to this (both the cooling and subsequent warming), but it’s not sufficient on its own to drive the entire process.
I don’t really know how to respond to this. It’s simply wrong.
I wonder if Lord May was as unable to answer you as jshore, aptronym, kimstu, and others who’ve been posting in these threads. What would it take, in your eyes, to answer that question?
Actual evidence. Not models, evidence.
And what form would this evidence take? Let’s face it, there is no evidence that will convince you. If you wish to throw out the use of models, then you wish to throw out science. Models are central to nearly all branches of science, from AI research to epedemiology.
As I said in the other thread, I prefer not to get sidetracked here.
What are you talking about? The only calculation you present doesn’t even include a variable for CO2. Please give me a cite that the estimated size of warming due to CO2 (based on a simple calculation from first order principles) matches the size of the observed effect.
I doubt it. If it were possible to demonstrate the currently popular CO2 AGW theory with a first order calculation (and without models that incorporate positive feedback loops) the warmers would be screaming about it from the rooftops.
But just give me a cite.
Of course I’m debating the substantive issues. What do you think I’m posting about?
I think you’re incorrect here, but there’s no need to argue over semantics. By “sensitive” I am referring to sensitivity to CO2. A model that predicts a lot of warming for a certain increase in CO2 levels is sensitive. A model that predicts less warming for the same increase is less sensitive.
That’s incorrect, as I mentioned in my economic growth thread. If you know the Owner’s Equity of a corporation, it’s possible to compare Assets and Liabilities without knowing the actual values of those two quantities. It’s simple mathematics.
There have been land use changes near many temperature monitoring stations. This may have screwed up the instrumental record.
Can you please quote the selections you believe are important? Thanks!!
Can you quote the selection you believe supports this position?
Here’s what Cecil Adams said on the subject:
http://www.straightdope.com/columns/060407.html
Now, perhaps Cecil is wrong. But it’s not necessarily unreasonable to consider the questions out of order.
This is not a reply to your quote, but rather an interesting observation – recorded sunspot history only goes back a few hundred years. Early observations suffer from the same problems that early temperature observations suffer from - people didn’t do things as well as we do now. Most of the solar minima that you cited, as well as the whole concept of a “Little Ice Age”, come from proxy data fitted with mathematical modeling.
Why is it that you’re so quick to accept models of solar activity and temperature reconstruction, but not climatological models?
But there is. My first post is full of that evidence; my previous post to brazil84 has even more.
Perhaps you are confusing “I don’t understand the evidence” with “There is no evidence”? The only explanation I can think of is that you just don’t see the connection between radiative forcing (snooze, snooze) and global warming.
My question about the effects of global warming has to do with the melting of the ice caps. I understand about rising sea levels and such, but I was always led to believe that we needed the polar-ice regions to help regulate life on Earth. Something about their cooling effect. The mechanics of this escapes me now, but suffice it to say that years ago, pre-global-warming concerns, I read this. So, if all of the ice were to melt – and I mean all of it, Antarctica, the Arctic, everywhere – would survival still be possible?
My main concern with global warming is the survival of our species. I figure global warming is NOT going to be reversed, snappy slogans notwithstanding, and so I hope that after a century or two, we’ll get into the swing of the new pattern.
Before I post it, let me first berate you for not reading carefully. 99% of your complaints in this thread now come directly from refusing to read what is posted to you, what is linked to you, and what is cited to you.
I seriously question any sort of intellectual honesty you have.
Quoting from Post #1 in this thread (not using the quote function to keep the formatting consistent)
"based on Earth’s distance from the Sun and the Stefan-Boltzmann blackbody radiation law, Earth should be a frigid -15[sup]o[/sup]C on average. Yet its average temperature is +20[sup]o[/sup]C - a 35[sup]o[/sup]C warming which is due to greenhouse gases - about 95% due to water (H[sub]2[/sub]O), and 5% due to carbon dioxide (CO[sub]2[/sub]), with all the rest of the gases contributing some miniscule amount. If the greenhouse effect were to be doubled, water would start spontaneously boiling in the tropics, and if the greenhouse effect were to be eliminated, water would freeze everywhere except for the tropics.
Not surprisingly, increasing the CO[sub]2[/sub] (or H[sub]2[/sub]O, but we don’t generate enough) will increase the greenhouse effect. This difference is anthropogenic global warming. Experimentally, we’re seeing a 38% increase in CO[sub]2[/sub] levels since the Industrial Revolution, which, if the greenhouse effect were linear, would correspond to about a 0.7[sup]o[/sup]C warming. Just to be clear, the greenhouse effect is certainly not linear, but we’re in the right ballpark here."
I HEREBY SHOUT IT FROM THE ROOFTOP - READ THE OP, IT CONTAINS A FIRST-PRINCIPLE CALCULATION WITHOUT ANY MODELS THAT SHOWS THE MAGNITUDE AND DIRECTION OF OBSERVED CO[sub]2[/sub] LEVELS MATCHES THE INCREASE IN GREENHOUSE EFFECT!
Is that good enough for you? Is there any way I can make this any clearer to you?
I think you have spent 80% of your time desperately trying to bring in the hockey stick into this conversation and 20% of your time asking for citations of things I have already cited.
Thus, it is unsurprising that, if you define “sensitive” as “increases with CO[sub]2[/sub]”, that the increase in CO[sub]2[/sub] would be largest with the most “sensitive” models.
It also occurred to me that another fundamental misunderstand you might have is that you think all the models predict the same CO[sub]2[/sub] increases. You’d be wrong - read the descriptions of the SRES in the IPCC reports; they list not only the expected CO[sub]2[/sub] rise for each SRES, but also a bunch of other factors.
Either way, I’d like to point out as a theme that both the definition of “sensitivity” and the description of CO[sub]2[/sub] levels in each SRES are linked in the first post of this thread.
Is this a specific example that works, or is it a general example? Do you honestly believe that any two values can be compared if their magnitudes aren’t known, or do you simply think that the case you’re citing can be applied to this case?
Okay, so how do you contest the satellite temperature record which matches the instrumental temperature record from 1980-2000?
I’ve already quoted the selections that I believe are important. You don’t exude enough intellectual honesty to make me believe that you’re not just trying to waste people’s time.
I’ll make you a deal - you show one example of having read any portion of the IPCC 3AR, NAS CCR, or IPCC 4AR by addressing one passage (either supporting it by rephrasing it or by bringing up a non-obvious question) which has not already been quoted on this thread.
In return, I will quote the exact selections that are important.
Yes, I could. But I’d be half-tempted to fabricate a quote just to see whether you fact-check.
Ah, but this thread is not about considering the questions out of order - that was a topic that was brought up in your “Economic hockey stick” thread in which you specifically said that you were willing to consider the climatological evidence for anthropogenic global warming without any discussion of the economics of stopping it.
Cecil is exactly right for the exact question he is answering: “Is Kyoto a good treaty?” And the answer is, correctly, no. At the present time, emissions are proportional to economic output; at the present time, there is no way to cut emissions without cutting economic output. Hence, Kyoto will not work as a treaty so long as emissions are proportional to economic output.
However, if there comes a day when we can cut emissions without hurting our economy, Cecil would have to change his answer. Whether that day is now is a whole other debate.
Don’t you dare think about turning that question into the topic of this thread. In the FIRST POST OF THIS THREAD ATTENTION BRAZIL84 READ THIS NEXT PART CAREFULLY BECAUSE YOU SEEM TO HAVE MISSED IT THE FIRST TIME I specifically stated:
“Things not to be discussed:
(1’) I believe there is a giant conspiracy between the ACLU, the Illuminati, NAMBLA and scientists to bring about the New World Order using global warming to crush democracy and freedom.
(2’) Any solution we implement is going to have to involve China and India.
(3’) It’s going to cost too much to fix global warming.”
But I’m not. As I said, I don’t find it compelling. And reconstructions are different from models - neither of us argue the temperatures reconstructed from the ice cores, do we?
The problem I have is that I see the correlation (that it might), but not the link that demonstrates the causation (that it does).
For instance, Enginerd thusly dismissed the end of the Little Ice Age:
We’re only at the temperature of the MWP. And that wasn’t caused by AGW, was it?
I guarantee you (and I believe 99% of scientists would agree with this guarantee) that there is a 0% chance of anthropogenic global warming causing the extinction of the human species.
Keep in mind that this guarantee does not include displacement of hundreds of millions from flooded lowlands, worldwide starvation due to drought, spread of tropical diseases into currently-temperate areas, or massive migrations into subpolar regions. All I’m guaranteeing is that 15 men and 15 women capable of reproducing will survive and find each other.
I don’t think you really want to make survival of a species your main concern - I think that our species would also survive a nuclear weapon detonated in a major U.S. city, but I would still advocate taking steps to reduce the probability of that happening. I would (1) first make sure the possibility is real, (2) find out how the possibility increases or decreases with our actions, (3) weigh the cost of inaction against the cost of action, and (4) try to gather everyone who would be affected to forumlate an action plan.
I advocate doing nothing less for anthropogenic global warming.
This thread is about whether global warming is (a) real, and/or (b) anthropogenic, and/or © harmful. I am specifically excluding discussion about how much it might cost to fix any problems, what technological developments might be needed, as well as discussion about what other nations would have to do to make a plan work. This is meant as a science thread.