Scientists don't attempt to separate everything. Much of modern physics has been concerned with unifying things together, in fact. A lot of that unification has been with the fundamental forces. String theory provides one way to unify the forces (e.g., electromagnetism or "light") with matter: force-carrying particles and matter particles are both vibrational modes of strings. The "string net condensation" idea is a different way to unify light and matter: forces as strings, matter as the endpoints of the strings. This is also related to ideas in string theory, but its realization in a condensed matter system instead of in terms of fundamental strings is new.
In the traditional Landau paradigm, phases of matter arise as broken symmetries of the Hamiltonian, with different phases corresponding to different symmetries and described by a "local order parameter" (e.g. magnetization).
With the advent of developments in high-temperature superconductivity and the quantum Hall effect, new phases were found that exist completely outside the Landau paradigm: topological order, in which there is no local symmetry, yet the topology of the system can globally distinguish one phase from another.
Excitations of these systems with topological order were once thought to be necessarily "gapped", that is, the quasiparticle excitations have an effective mass. However, Wen has proposed a more general notion of "quantum order", in which gapless (massless) quasiparticles, analogous to photons or other gauge vector bosons, can appear.
The mechanism by which this occurs, in Wen's paradigm, is through "string net condensation". In quantum field theory, from the work of Polyakov and others, it is possible to think of the field lines connecting particles as "strings", with the particles residing at the endpoints of the strings. The fields are gauge fields, so the "stringy" field lines correspond to the massless gauge bosons, as opposed to the massive matter particles that serve as the string endpoints. Wen's quantum order has excitations in a spin lattice correspond effectively to strings (massless "force field" quasiparticles), which are open, i.e., have endpoints (massive "matter" quasiparticles).
There are actually strong analogies between these ideas and actual string theory (as noted by my reference to Polyakov's work). In fact, Wen did his Ph.D. in string theory under Edward Witten before switching to condensed matter.
The work discussed in this story is an experimental demonstration of a system with gapless excitations that do not obey Landau's local order paradigm, and thus relate to Wen's work on quantum order. (I am fuzzy on the details so I don't know to what extent this work is a confirmation of Wen's theories. I also don't know how novel gapless excitations are without symmetry breaking.)
You can read more about this from his work, such as this. Wen has even proposed that perhaps the actual photons and electrons we think are real are really just quasiparticle excitations arising from a low energy (large scale) effective field theory of some underlying submicroscopic lattice that we can't see — see here: he can recover many (but not all) of the aspects of the particle physics this way, and argues that it unifies light and matter (since open strings always have endpoints). I think he has problems with chiral fermions, IIRC. The big stumbling block is of course gravity, although he has made efforts in that direction too (here). He has written a graduate textbook on these ideas; he also has some talks up on his web page.
I cannot take you seriously when you suggest that the NAS report supported the hockey stick. Did you read it? They found some errors in Mann's reconstruction, and concluded that when you fix them, you still get a hockey stick, but with greater uncertainty in the pre-1600 temperatures. (Wegman did not bother to check what the effect on the reconstructions are.) In fact, the reconstruction does not change much from Mann's original graph, and the NAS stated explicitly that Mann's methodology did not unduly bias the temperature reconstructions. In particular, the NAS report confirmed that there is anomalous 20th century warming compared to the last 400 years, and plausibly over the last 1000, which is the entire scientific content of the hockey stick. And, as I remarked previously, no one has ever "demolished" any of the other independent temperature reconstructions, using different methods, which also show hockey sticks.
I note also the complete absence of any response to any of my other refutations of your claims.
You're chastising me for having a different cosmological preference (as if that's a bad thing!) rather than embracing the notion that lots of people can happily coexist with lots of different cosmological beliefs. I am not chastising you for your preferences, I am pointing out that just because cosmologists reject your favorite theory doesn't mean they don't think outside the box.
I've made a specific point of not even mentioning what my preferences are within this thread It is no great secret which theory you gush over in pretty much every Slashdot thread remotely related to astronomy.
The fact that he is in a field of experts who realize that they have major problems and yet do not actively promote out-of-the-box thinking remains. This is nonsense. Your problem is that they do not promote the specific alternative theory that you happen to fancy. Fortunately, this is not actually a problem for cosmology.
Hawking's theories of quantum cosmology are out of the mainstream. The whole Euclidean quantum gravity program upon which they are founded is no longer very popular at all.
I can provide more references for specific points if you tell me which ones.
I looked earlier in this thread, but did not see evidence for the first point you made. All I saw was a news story about some polar explorers who underestimated the weather. This is different from a claim that climate models actually predicted warmer weather than has been observed.
I've been commenting on this story since it was first posted, and keep tabs on it since new arguments are posted from time to time.
He was talking about something different from the theory you are talking about, the Hartle-Hawking no-boundary proposal. What he was describing sounds like Linde's eternal inflation framework, which is not new. Perhaps Hawking newly favors it. You can read a nice description of it in Guth's pop-sci book on inflation.
Maybe what we really need is for the astrophysicists to spend more time on the problems, collaborating with the various peoples' of the domains that they work within, and less time demonstrating that they've mastered the art of public relations. Spending time on the problems what the vast majority of scientists spend the majority of their time doing. Which is not to say that they shouldn't spend time communicating their results to the public. Scientists should continue to give talks on basic concepts regardless of whether the concepts are old or new. There are always people who have not heard them.
I'm getting tired of intellectually lazy Slashdotters dismissing arbitrarily complex arguments by labelling them "blind faith".
In the context of the kind of eternal inflation Hawking is talking about, the inflaton field is something that has always existed in the universe (along with all the other fields: the electron field, quark fields, gravitational and electromagnetic fields, etc). Due to its dynamics, it continuously spawns "bubble" universes by quantum fluctuation.
The laws of physics do not tell us why the universe happens to contain those fields. But inflationary theory suggests that if one of the fields which happens to exist is an inflaton field, then it's possible for eternal "universe creation" to happen.
This is speculation, but it is not "blind faith". It is science. The idea of inflationary cosmology was proposed to explain a number of observational aspects of the universe (such as the horizon and flatness problems), and has made new predictions which have subsequently been confirmed (the CMBR angular power spectrum). The idea of eternal universe creation is much harder to test, and ultimately may not be testable, yet still falls within the realm of science because it is a prediction of a theory which makes other predictions which can be tested.
The fact that science cannot (yet) explain where the inflaton field comes from in the first place does not make the idea "faith". It's like claiming that because you don't know how life first arose on Earth, then all of evolutionary biology must be "blind faith". No, you can have evidence or theoretical motivations to believe the latter without having a clue about the former. And just because it's been proposed, doesn't mean you have to believe it, either. It's a hypothesis, not something that is being asserted as unquestionable fact.
1. Arctic temperatures are lower than Global Warming experts predicted. Where's the refined model that accounts for that? 2. Arctic and antarctic ice formations are increasing. Where's the refined model that accounts for that? 3. Glaciation in the Himalayas is increasing. Where's the refined model that accounts for that? 4. The average temperatures on Mars are increasing. Where's the refined model that accounts for that? 5. Solar energy output is increasing. Do you think maybe it's the Sun that's causing Global Warming? 6. In fact, global average temperatures went down in the middle of the 20th century, even as man-made CO2 output went up. 7. Coincidentally, Solar energy output also went down during the same period. Do you think maybe it's the Sun that's causing Global Warming? 8. Not only that, but geological records show that increased levels of atmospheric CO2 trail behind Global Warming trends by 800 years or more. Where's the refined model that accounts for that? 1. What is the evidence for this claim? 2. Models generally predict increased precipitation which leads to snow/ice accumulation in the center of land masses, but ice loss at the coastlines, which is what is predicted. Overall Arctic ice is decreasing, while Antarctic ice may be increasing. 3. I read that as of 2005, 2/3 of the Himalayan glaciers are retreating. What is the evidence for this claim? I don't know myself whether models predict an overall increase or decrease in glaciation in the Himalayas, but global warming does not necessarily predict a decrease in all ice (see point 2). 4. There is no evidence that global temperatures on Mars are increasing, just polar temperatures. Furthermore, there is only one possible factor in common with Martian and Earth climates, and that is solar output. Solar output is not responsible for the warming on Mars, because it actually decreased slightly over most of the years of observation of polar warming. Other factors such as topographically-induced climate instability have been proposed. 5. The Sun is not causing global warming. Solar output has increased, but the amount of its increase is too small to account for the majority of the warming which has taken place. See the 2006 Nature review study of Foukal et al. The Sun does contribute to some of the warming, but it cannot explain most of it, not even combined with all other natural forcings. 6. Global average temperatures went down 1940-1970 because of increased concentrations of atmospheric aerosols and particulate matter due to air pollution. The amount of cooling observed agrees with the amount of cooling predicted by the known amounts of atmospheric contaminants. 7. See point 5. 8. The 800-year lag corresponds roughly to the response time of oceanic CO2 uptake. When a warming trend begins (and in the case of the 800-year lag seen in the ice age cycle, this warming trend is probably kicked off by Earth's orbital variations), the ocean loses some of its capacity to store carbon. After 800 years of warming, atmospheric CO2 levels rise. The increased CO2 levels substantially amplify and prolong the warming trend past what the external forcing (e.g., orbital variations) alone would produce.
CO2 levels have been significantly higher in the past, although not for the last million years or so at least. However, there is no record of a CO2 rise this rapid before.
I'm rather dubious of the value of the SPM - a summary by policy makers for policy makers (and why on earth wasn't AR4 released before the summary?). For example, figure SPM-4 suggests global land temperatures have risen 1C over the 20th century. That is substantially larger than the other estimates I've seen.
What estimates have you seen? The HADCRUT3 land temperature data, for instance, indicates a temperature anomaly of about -0.3 degrees in 1900 and +0.7 degrees in 2005, which is entirely consistent with Fig. SPM-4. See Brohan et al. (2006), Figure 12.
Moreover, there are no error bars on the global land temperature line. Is this the upper bound? The lower bound?
If you're referring to the black line (observations), it's the decadal average. If you're referring to the shaded bands, they're the 5-95% confidence interval.
How were these data computed? In short, it's not a scientifically useful figure.
It's a summary for policymakers, which has a lot of useful information in one place. If you want more, you are welcome to read the literature.
Regarding parameter tuning, the whole reason for having the parameters is because your model doesn't work without them. Having complete parameterisability has nothing to do with overfitting; you can overfit any parameterised model to the training data.
What is your point? I thought it was that a large number of parameters means that you can tune them to fit any data, and thus have no predictability — i.e., overfitting. The fact that you cannot in fact tune the parameters to reproduce any set of data, as well as their hindcasting skill, indicates that the models do have predictive value.
On that note, comparing multiple runs of multiple models emphatically does not give you error bars.
Pure nonsense. If you sample the parameters from whatever probability distribution you believe they have, the model runs on those samples are by definition samples from the probability distribution of climate predictions, from which error bars can be constructed.
It merely allows you to compare the outputs of models for a statistically insignificant sample of their parameter settings.
The samples are not statistically insignificant, and if you want better sampling, you can turn to EMICs instead of GCMs.
It says nothing whatsoever about the validity of those outputs.
More nonsense. The way any theory is tested is to see if its predictions agree with observations, to within the accuracy of the prediction and the accuracy of the observation (their respective error bars).
On the UHI, I do not believe it has been shown to be negligible.
Try the references in the Brohan paper (section 2.2.3), not a paper from 1990.
I am not at all surprised that models do well compared to weather station measurements, because they are trained on that data!
You can't construct a climate model with no data. You can, however, have a measure of confidence whether it is overfitting by hindcasting/cross validation, testing whether it can fit arbitrary data, and intermodel comparison.
I do not believe that thermometers read by humans are going to give more than 1C of accuracy or that they have been consistently read at the same times each day for a century or that most of them haven't been moved around. Plus there is the fact that there are not very many of them and virtually all of them are in well inhabited areas
Some thermometers give more than 1C accuracy, particularly modern thermometers; others don't. Global averages reduce the overall error. If you want to claim that reading them at different times of the day biases the conclusion, you have to show that a large fraction of them are all misread with large delays that reinforce each other. Ditto with moving them around. Such biases are corrected for when known (sec. 2.3.1 o
The one thing I know, with out a doubt about science is nothing is closed for debate...except this. Wonder why?
Climate science isn't "closed for debate", either. You can debate that the climate isn't changing or humans aren't causing it. You can also debate that disease isn't caused by germs. You just look foolish either way.
The fact is, CO2 in our atmosphere actually would make it cooler, not warmer.
That "fact" is contradicted by both experiment, observation, and the laws of physics.
First, those links have nothing to do with the point under discussion. I indicated in detail why you were wrong about global cooling, but you didn't read the links. You responded with other links that have nothing to do with global cooling. Changing the subject doesn't win you any points.
Second, your first link contradicts the statement you made above, that CO2 in our atmosphere makes the climate cooler. It states explicitly that temperature rises with increasing CO2 — it just claims that the observed rise is not as large as predicted.
Perhaps you were confused by the sentence which reads, "The impact on temperature per unit CO2 goes down, not up, with increasing CO2." That does not mean that temperature goes down with increasing CO2. It means that the increase in temperature goes down with increasing CO2, i.e., as you increase CO2, the temperature still increases, but not by as much as lesser increases of CO2. This is the well known logarithmic dependence of radiative forcing on CO2 concentration, which is mentioned in the very same paragraph (in terms of a fixed additive change in temperature for a fixed multiplicative increase in CO2, i.e., a logarithmic relationship).
If you would like to discuss other scientific claims made elsewhere in that link, state which ones you want to debate.
The second link contains nothing but the opinion of a politician, and no science at all.
Other than 2 links to your propaganda sites, what science have you quoted?
Once again, you choose to dismiss any science that does not agree with your point of view.
Climatology even mentions Meteorology in it's definition.
The fact is, climatologists are not meteorologists, they apply for different jobs and often work in entirely different departments, and they publish in different journals. Most relevantly, and as I pointed out before, the chaotic limitations of weather forecasting do not apply to climate forecasting, for reasons I already stated.
I noticed that you just called me "ignorant" but did nothing to prove me wrong.
Mitigating climate change does not imply that the world economy will be "upset", unless you consider any expenditure to upset the economy. Consider the studies of economists like Richard Tol and William Nordhaus, whose work indicates that there is no need for catastrophic spending to mitigate climate change. Tol even argues that there are short-term benefits which will substantially offset the costs of mitigation.
You are just following a washed up senator that couldn't even carry his own state in his bid for President.
I couldn't care less what Al Gore thinks, but it won't stop you from making ad hominem attacks instead of real debate.
Yep, just like in the 70's when it was global cooling.
This is wrong, as I pointed out in my very first response to you.
Warm your freezer up by 3 degrees, did your ice melt? Didn't think so.
I am at a loss as to what you are asserting. Are you really claim
(1) There is debate as to whether or not the "current global warming trend", as you put it, even exists. Debate from who? Even the most hard-line skeptics admit there is warming nowadays.
(2) If we assume that there is a trend of steadily increasing temperatures on the planet, it is still uncertain if this is caused by human activity or is an indication of natural processes at work in extremely long and hard-to-predict (let alone measure) geological cycles. 1. There is no paleoclimate evidence of any long geological cycle suddenly coming due right now. 2. Geological cycles are generally much slower than the climate change now happening (with the exception of thermohaline circulation collapse). 3. Even if we had no evidence one way or another about the past climate, the current natural processes just don't agree with the timing, rate, or magnitude of the climate change that is now happening.
Anthropogenic global warming simply is not nearly as uncertain as you would claim. The case for it is by now quite strong. The main uncertainty now is mostly on how climate feedbacks and forcing variations will affect future warming, not on the attribution of existing warming to human activity.
You should note that a significant reason why the acid rain "hysteria" didn't "pan out" is because the emission controls, which you contend are an unnecessary economic hardship, actually did substantially reduce pollution. (Ditto for the ozone hole problem.)
That being said, the effects of acid rain are not as bad as the worst-case scenarios being tossed around in the media in the 1980s.
I would be interested, however, to see references to the scientific literature of the time which asserted "how over 50% of lakes in northeast states were beyond saving because of the amount of acid rain contamination, how a large percentage (close to and soon to surpass 10%) were so contaminated that all the fish in those lakes would be dead in just a few years, and how in the 50%+ contaminated lakes, the lakes would be so contaminated within 10 years that it would be too late to save them and all the fish in these lakes would be dead within the ten years, and in the remaining lakes, they faced the same dire consequences but with a slightly longer time span".
As for arrogance, it is not arrogance to believe that humans can adversely affect the environment. They have before and they are doing it now. It is a fallacy to assume that we cannot adjust our actions as we learn more. As for the accuracy of projections, the point is to design a policy that is robust across the full spectrum of possibilities, which is what is being attempted.
The very article you cite explains why the climate of different planets changes for different reasons. (It also does not claim that all of the planets are warming.) In few if any of the cases is the warming due to "the Sun", and few if any of the planets are experiencing climate change for the same reasons.
I am well aware of Hume's work on inductive inference. The fact is, science does give evidence of causal relationships, and everyone including yourself acts as if it does — Hume notwithstanding — except when the science is inconvenient to your position. Otherwise, why take antibiotics? There is no proven causal relationship between antibiotics and disease. Why avoid stepping into open manholes? There is no proven causal relationship between doing so and falling. The laws of physics can't be used to predict anything, after all. All models and theories are worthless.
When you have to resort to the claim that science cannot produce causal links between phenomena, the argument has proceeded beyond the absurd into the pointless.
Slashdot Mirror
It's named after its discoverer, H. Erbertsmithite.
Scientists don't attempt to separate everything. Much of modern physics has been concerned with unifying things together, in fact. A lot of that unification has been with the fundamental forces. String theory provides one way to unify the forces (e.g., electromagnetism or "light") with matter: force-carrying particles and matter particles are both vibrational modes of strings. The "string net condensation" idea is a different way to unify light and matter: forces as strings, matter as the endpoints of the strings. This is also related to ideas in string theory, but its realization in a condensed matter system instead of in terms of fundamental strings is new.
In the traditional Landau paradigm, phases of matter arise as broken symmetries of the Hamiltonian, with different phases corresponding to different symmetries and described by a "local order parameter" (e.g. magnetization).
With the advent of developments in high-temperature superconductivity and the quantum Hall effect, new phases were found that exist completely outside the Landau paradigm: topological order, in which there is no local symmetry, yet the topology of the system can globally distinguish one phase from another.
Excitations of these systems with topological order were once thought to be necessarily "gapped", that is, the quasiparticle excitations have an effective mass. However, Wen has proposed a more general notion of "quantum order", in which gapless (massless) quasiparticles, analogous to photons or other gauge vector bosons, can appear.
The mechanism by which this occurs, in Wen's paradigm, is through "string net condensation". In quantum field theory, from the work of Polyakov and others, it is possible to think of the field lines connecting particles as "strings", with the particles residing at the endpoints of the strings. The fields are gauge fields, so the "stringy" field lines correspond to the massless gauge bosons, as opposed to the massive matter particles that serve as the string endpoints. Wen's quantum order has excitations in a spin lattice correspond effectively to strings (massless "force field" quasiparticles), which are open, i.e., have endpoints (massive "matter" quasiparticles).
There are actually strong analogies between these ideas and actual string theory (as noted by my reference to Polyakov's work). In fact, Wen did his Ph.D. in string theory under Edward Witten before switching to condensed matter.
The work discussed in this story is an experimental demonstration of a system with gapless excitations that do not obey Landau's local order paradigm, and thus relate to Wen's work on quantum order. (I am fuzzy on the details so I don't know to what extent this work is a confirmation of Wen's theories. I also don't know how novel gapless excitations are without symmetry breaking.)
You can read more about this from his work, such as this. Wen has even proposed that perhaps the actual photons and electrons we think are real are really just quasiparticle excitations arising from a low energy (large scale) effective field theory of some underlying submicroscopic lattice that we can't see — see here: he can recover many (but not all) of the aspects of the particle physics this way, and argues that it unifies light and matter (since open strings always have endpoints). I think he has problems with chiral fermions, IIRC. The big stumbling block is of course gravity, although he has made efforts in that direction too (here). He has written a graduate textbook on these ideas; he also has some talks up on his web page.
The preprint.
I note also the complete absence of any response to any of my other refutations of your claims.
Hawking's theories of quantum cosmology are out of the mainstream. The whole Euclidean quantum gravity program upon which they are founded is no longer very popular at all.
My link vanished from my previous comment.
't Hooft addressed Bell's theorem in section 6 of his first paper on his dissipative deterministic quantum theory.
(Ok, I liked some of his earlier novels...)
I can provide more references for specific points if you tell me which ones.
I looked earlier in this thread, but did not see evidence for the first point you made. All I saw was a news story about some polar explorers who underestimated the weather. This is different from a claim that climate models actually predicted warmer weather than has been observed.
I've been commenting on this story since it was first posted, and keep tabs on it since new arguments are posted from time to time.
He was talking about something different from the theory you are talking about, the Hartle-Hawking no-boundary proposal. What he was describing sounds like Linde's eternal inflation framework, which is not new. Perhaps Hawking newly favors it. You can read a nice description of it in Guth's pop-sci book on inflation.
I'm getting tired of intellectually lazy Slashdotters dismissing arbitrarily complex arguments by labelling them "blind faith".
In the context of the kind of eternal inflation Hawking is talking about, the inflaton field is something that has always existed in the universe (along with all the other fields: the electron field, quark fields, gravitational and electromagnetic fields, etc). Due to its dynamics, it continuously spawns "bubble" universes by quantum fluctuation.
The laws of physics do not tell us why the universe happens to contain those fields. But inflationary theory suggests that if one of the fields which happens to exist is an inflaton field, then it's possible for eternal "universe creation" to happen.
This is speculation, but it is not "blind faith". It is science. The idea of inflationary cosmology was proposed to explain a number of observational aspects of the universe (such as the horizon and flatness problems), and has made new predictions which have subsequently been confirmed (the CMBR angular power spectrum). The idea of eternal universe creation is much harder to test, and ultimately may not be testable, yet still falls within the realm of science because it is a prediction of a theory which makes other predictions which can be tested.
The fact that science cannot (yet) explain where the inflaton field comes from in the first place does not make the idea "faith". It's like claiming that because you don't know how life first arose on Earth, then all of evolutionary biology must be "blind faith". No, you can have evidence or theoretical motivations to believe the latter without having a clue about the former. And just because it's been proposed, doesn't mean you have to believe it, either. It's a hypothesis, not something that is being asserted as unquestionable fact.
Actually, I think he was describing Linde's eternal inflation, not braneworld scenarios.
2. Arctic and antarctic ice formations are increasing. Where's the refined model that accounts for that?
3. Glaciation in the Himalayas is increasing. Where's the refined model that accounts for that?
4. The average temperatures on Mars are increasing. Where's the refined model that accounts for that?
5. Solar energy output is increasing. Do you think maybe it's the Sun that's causing Global Warming?
6. In fact, global average temperatures went down in the middle of the 20th century, even as man-made CO2 output went up.
7. Coincidentally, Solar energy output also went down during the same period. Do you think maybe it's the Sun that's causing Global Warming?
8. Not only that, but geological records show that increased levels of atmospheric CO2 trail behind Global Warming trends by 800 years or more. Where's the refined model that accounts for that? 1. What is the evidence for this claim?
2. Models generally predict increased precipitation which leads to snow/ice accumulation in the center of land masses, but ice loss at the coastlines, which is what is predicted. Overall Arctic ice is decreasing, while Antarctic ice may be increasing.
3. I read that as of 2005, 2/3 of the Himalayan glaciers are retreating. What is the evidence for this claim? I don't know myself whether models predict an overall increase or decrease in glaciation in the Himalayas, but global warming does not necessarily predict a decrease in all ice (see point 2).
4. There is no evidence that global temperatures on Mars are increasing, just polar temperatures. Furthermore, there is only one possible factor in common with Martian and Earth climates, and that is solar output. Solar output is not responsible for the warming on Mars, because it actually decreased slightly over most of the years of observation of polar warming. Other factors such as topographically-induced climate instability have been proposed.
5. The Sun is not causing global warming. Solar output has increased, but the amount of its increase is too small to account for the majority of the warming which has taken place. See the 2006 Nature review study of Foukal et al. The Sun does contribute to some of the warming, but it cannot explain most of it, not even combined with all other natural forcings.
6. Global average temperatures went down 1940-1970 because of increased concentrations of atmospheric aerosols and particulate matter due to air pollution. The amount of cooling observed agrees with the amount of cooling predicted by the known amounts of atmospheric contaminants.
7. See point 5.
8. The 800-year lag corresponds roughly to the response time of oceanic CO2 uptake. When a warming trend begins (and in the case of the 800-year lag seen in the ice age cycle, this warming trend is probably kicked off by Earth's orbital variations), the ocean loses some of its capacity to store carbon. After 800 years of warming, atmospheric CO2 levels rise. The increased CO2 levels substantially amplify and prolong the warming trend past what the external forcing (e.g., orbital variations) alone would produce.
CO2 levels have been significantly higher in the past, although not for the last million years or so at least. However, there is no record of a CO2 rise this rapid before.
I'm rather dubious of the value of the SPM - a summary by policy makers for policy makers (and why on earth wasn't AR4 released before the summary?). For example, figure SPM-4 suggests global land temperatures have risen 1C over the 20th century. That is substantially larger than the other estimates I've seen.
What estimates have you seen? The HADCRUT3 land temperature data, for instance, indicates a temperature anomaly of about -0.3 degrees in 1900 and +0.7 degrees in 2005, which is entirely consistent with Fig. SPM-4. See Brohan et al. (2006), Figure 12.
Moreover, there are no error bars on the global land temperature line. Is this the upper bound? The lower bound?
If you're referring to the black line (observations), it's the decadal average. If you're referring to the shaded bands, they're the 5-95% confidence interval.
How were these data computed? In short, it's not a scientifically useful figure.
It's a summary for policymakers, which has a lot of useful information in one place. If you want more, you are welcome to read the literature.
Regarding parameter tuning, the whole reason for having the parameters is because your model doesn't work without them. Having complete parameterisability has nothing to do with overfitting; you can overfit any parameterised model to the training data.
What is your point? I thought it was that a large number of parameters means that you can tune them to fit any data, and thus have no predictability — i.e., overfitting. The fact that you cannot in fact tune the parameters to reproduce any set of data, as well as their hindcasting skill, indicates that the models do have predictive value.
On that note, comparing multiple runs of multiple models emphatically does not give you error bars.
Pure nonsense. If you sample the parameters from whatever probability distribution you believe they have, the model runs on those samples are by definition samples from the probability distribution of climate predictions, from which error bars can be constructed.
It merely allows you to compare the outputs of models for a statistically insignificant sample of their parameter settings.
The samples are not statistically insignificant, and if you want better sampling, you can turn to EMICs instead of GCMs.
It says nothing whatsoever about the validity of those outputs.
More nonsense. The way any theory is tested is to see if its predictions agree with observations, to within the accuracy of the prediction and the accuracy of the observation (their respective error bars).
On the UHI, I do not believe it has been shown to be negligible.
Try the references in the Brohan paper (section 2.2.3), not a paper from 1990.
I am not at all surprised that models do well compared to weather station measurements, because they are trained on that data!
You can't construct a climate model with no data. You can, however, have a measure of confidence whether it is overfitting by hindcasting/cross validation, testing whether it can fit arbitrary data, and intermodel comparison.
I do not believe that thermometers read by humans are going to give more than 1C of accuracy or that they have been consistently read at the same times each day for a century or that most of them haven't been moved around. Plus there is the fact that there are not very many of them and virtually all of them are in well inhabited areas
Some thermometers give more than 1C accuracy, particularly modern thermometers; others don't. Global averages reduce the overall error. If you want to claim that reading them at different times of the day biases the conclusion, you have to show that a large fraction of them are all misread with large delays that reinforce each other. Ditto with moving them around. Such biases are corrected for when known (sec. 2.3.1 o
Who said I know nothing about science?
It's pretty obvious.
The one thing I know, with out a doubt about science is nothing is closed for debate...except this. Wonder why?
Climate science isn't "closed for debate", either. You can debate that the climate isn't changing or humans aren't causing it. You can also debate that disease isn't caused by germs. You just look foolish either way.
The fact is, CO2 in our atmosphere actually would make it cooler, not warmer.
That "fact" is contradicted by both experiment, observation, and the laws of physics.
http://abcnews.go.com/International/story?id=29387 62&page=1
http://www.speroforum.com/site/article.asp?idartic le=8342
I guess you're illiterate too.
First, those links have nothing to do with the point under discussion. I indicated in detail why you were wrong about global cooling, but you didn't read the links. You responded with other links that have nothing to do with global cooling. Changing the subject doesn't win you any points.
Second, your first link contradicts the statement you made above, that CO2 in our atmosphere makes the climate cooler. It states explicitly that temperature rises with increasing CO2 — it just claims that the observed rise is not as large as predicted.
Perhaps you were confused by the sentence which reads, "The impact on temperature per unit CO2 goes down, not up, with increasing CO2." That does not mean that temperature goes down with increasing CO2. It means that the increase in temperature goes down with increasing CO2, i.e., as you increase CO2, the temperature still increases, but not by as much as lesser increases of CO2. This is the well known logarithmic dependence of radiative forcing on CO2 concentration, which is mentioned in the very same paragraph (in terms of a fixed additive change in temperature for a fixed multiplicative increase in CO2, i.e., a logarithmic relationship).
If you would like to discuss other scientific claims made elsewhere in that link, state which ones you want to debate.
The second link contains nothing but the opinion of a politician, and no science at all.
Other than 2 links to your propaganda sites, what science have you quoted?
Once again, you choose to dismiss any science that does not agree with your point of view.
Climatology even mentions Meteorology in it's definition.
The fact is, climatologists are not meteorologists, they apply for different jobs and often work in entirely different departments, and they publish in different journals. Most relevantly, and as I pointed out before, the chaotic limitations of weather forecasting do not apply to climate forecasting, for reasons I already stated.
I noticed that you just called me "ignorant" but did nothing to prove me wrong.
Mitigating climate change does not imply that the world economy will be "upset", unless you consider any expenditure to upset the economy. Consider the studies of economists like Richard Tol and William Nordhaus, whose work indicates that there is no need for catastrophic spending to mitigate climate change. Tol even argues that there are short-term benefits which will substantially offset the costs of mitigation.
You are just following a washed up senator that couldn't even carry his own state in his bid for President.
I couldn't care less what Al Gore thinks, but it won't stop you from making ad hominem attacks instead of real debate.
Yep, just like in the 70's when it was global cooling.
This is wrong, as I pointed out in my very first response to you.
Warm your freezer up by 3 degrees, did your ice melt? Didn't think so.
I am at a loss as to what you are asserting. Are you really claim
2. Geological cycles are generally much slower than the climate change now happening (with the exception of thermohaline circulation collapse).
3. Even if we had no evidence one way or another about the past climate, the current natural processes just don't agree with the timing, rate, or magnitude of the climate change that is now happening.
Anthropogenic global warming simply is not nearly as uncertain as you would claim. The case for it is by now quite strong. The main uncertainty now is mostly on how climate feedbacks and forcing variations will affect future warming, not on the attribution of existing warming to human activity.
You should note that a significant reason why the acid rain "hysteria" didn't "pan out" is because the emission controls, which you contend are an unnecessary economic hardship, actually did substantially reduce pollution. (Ditto for the ozone hole problem.)
That being said, the effects of acid rain are not as bad as the worst-case scenarios being tossed around in the media in the 1980s.
I would be interested, however, to see references to the scientific literature of the time which asserted "how over 50% of lakes in northeast states were beyond saving because of the amount of acid rain contamination, how a large percentage (close to and soon to surpass 10%) were so contaminated that all the fish in those lakes would be dead in just a few years, and how in the 50%+ contaminated lakes, the lakes would be so contaminated within 10 years that it would be too late to save them and all the fish in these lakes would be dead within the ten years, and in the remaining lakes, they faced the same dire consequences but with a slightly longer time span".
As for arrogance, it is not arrogance to believe that humans can adversely affect the environment. They have before and they are doing it now. It is a fallacy to assume that we cannot adjust our actions as we learn more. As for the accuracy of projections, the point is to design a policy that is robust across the full spectrum of possibilities, which is what is being attempted.
The very article you cite explains why the climate of different planets changes for different reasons. (It also does not claim that all of the planets are warming.) In few if any of the cases is the warming due to "the Sun", and few if any of the planets are experiencing climate change for the same reasons.
What point were you trying to make again?
I am well aware of Hume's work on inductive inference. The fact is, science does give evidence of causal relationships, and everyone including yourself acts as if it does — Hume notwithstanding — except when the science is inconvenient to your position. Otherwise, why take antibiotics? There is no proven causal relationship between antibiotics and disease. Why avoid stepping into open manholes? There is no proven causal relationship between doing so and falling. The laws of physics can't be used to predict anything, after all. All models and theories are worthless.
When you have to resort to the claim that science cannot produce causal links between phenomena, the argument has proceeded beyond the absurd into the pointless.