It's worth keeping in mind that the modeled data lines up with reality because it's supposed to. That's how you calibrate your model, by making sure it fits reality.
The real trick is to see how well your model extrapolates from the data you have out into the future. As in, if you feed it data up to, say, 1990, will it correctly spit out 2015 temperatures that fit the reality of 2015, or will it spit out crazy 2015 predictions like the models that were built in 1990 did. And, the bigger question: How will its predictions for 2040 (given 2015 data) match up to the reality over the next 25 years.
We seem to be getting a lot better at the modeling side. That's a good thing, since the first couple decades of watching people panicking and fighting each other over whatever scary results came out of the first generation climate models wasn't any fun to watch.
"The real trick is to see how well your model extrapolates from the data you have out into the future."
That is the most common way to show the modeller is not shamelessly overfitting.:-| Another way, though, is less common but not vanishingly uncommon: the model may be so much simpler than the data it fits that overfitting is not a plausible explanation. (Roughly there are too many bits of entropy in the match to the data to have been packed into the model no matter how careless or dishonest you might have been about overfitting.) E.g., quantum mechanics is fundamentally pretty simple --- I can't quantify it exactly, but I think 5 pages of LaTeX output, in a sort of telegraphic elevator pitch cheat sheet style, would suffice to explain it to 1903 Einstein or Planck well enough that they could quickly figure out how to do calculations. Indeed, one page might suffice. And there are only a few adjustable parameters (particle/nucleus masses, Planck's constant, and less than a dozen others). And it matches sizable tables of spectroscopic data to more than six significant figures. (Though admittedly I dunno whether the non-hydrogen calculations would have been practical in 1903.) For the usual information-theoretical reasons, overfitting is not a real possibility: even if you don't check QM with spectroscopic measurements on previously unstudied substances, you can be pretty sure that QM is a good model. (Of course you still have to worry about it potentially breaking down in areas you haven't investigated yet, but at least it impressively captures regularities in the area you have investigated.)
It's not just a question of how the model extrapolates from the input data itself. The actual input data may be in question as well, because there are always judgments involved in deciding how to measure, what "unreasonable" datapoints will be discarded, etc.
Read, for example, here:
"It is indisputable that a theory that is inconsistent with empirical data is a poor theory. No theory should be accepted merely because of the beauty of its logic or because it leads to conclusions that are ideologically welcome or politically convenient. Yet it is naive in the extreme to suppose that facts – especially the facts of the social sciences – speak for themselves. Not only is it true that sound analysis is unavoidably a judgment-laden mix of rigorous reasoning (“theory”) with careful observation of the facts; it is also true that the facts themselves are in large part the product of theorizing. ..."
While the general gist of your argument is right, I think there are some non-trivial ways to overfit. There are some 25 constants in the standard model apparently that describe the world around us to enormous precision. This is so little information that of course the trivial 'overfitting by encoding observations directly' will fail, but we could still be overfitting by having an excess number of variables: perhaps there's really some mechanism in neutrino physics that explains neutrino oscillation without needing some constants to describe how it really happens. This might in turn boost tremendously our predictive precision for neutrino oscillation to match the precision of the other more fundamental variables in the model, for example. But I think you're right that it's so little data that we have some strong information theoretic guarantees that at least the model will have predictive power matching the precision of previous measurements.
Well - that's true apart from co-incidence. You can have a very simple theory which says "x is directly caused by y" and there is a lot of good data, and a great fit. But it's kist a co-incidence and breaks down immediately.
Occam's razor is a rule of thumb and an aesthetic boon, but nothing more.
The real test is that you have a theory that is meaningful and has explanatory power. If it grants insight on the mechanisms that are driving the relationships or generating the data and these make sense - you are pretty golden.
Another one is that the theory makes unexpected predictions that you can then test. This is a real winner, and why complex physics is so well regarded.
I think the information theoretic approach to modeling concerns actually implies such "simpler is better" approaches as Occam's Razor. At least that's my take on [http://arxiv.org/abs/cond-mat/9601030], which derives a quantitative form of it.
I haven't read that paper, and the abstract makes my head spin! I'll have a look later, and try and figure out the argument. I agree with you that things like the I-measure are based on the idea that simpler is good, and it works well in practice - both in Machine Learning and in the real world - which is why humans tend to prefer it. But (the paper you cite aside) I don't know of a deep reason why simple is preferred by nature.
Also there is a deep cognitive bias here, perhaps we lack the machinery to understand the world as it really is!
> Occam's razor is a rule of thumb and an aesthetic boon, but nothing more.
Occam's razor is a bit more than that. It isn't just that given a theory X and a theory Y = X + ε, both of which fit the facts, you should prefer X because it's "cleaner" or more aesthetically pleasing or whatever. You should prefer X because you can prove it is more likely to be true.
No, it was a thought experiment I made up, not an exercise I've ever seen performed: how abbreviated a description of quantum mechanics could I get away with and still convey the idea to on-the-eve-of-QM scientists?
The QM equations are naturally very short, the stuff that I would worry about expressing concisely are concepts like what probability amplitude is, how it connects to prior-to-QM concepts of probability, the interpretation of what it means to make an ideal measurement, stuff like that. I don't know of any bright concise formulation of that stuff, and I'm not sure how I'd do it. I am fairly sure, though, that 5 pages could get the job done well enough to connect to spectroscopic observations.
Note also in the original story it was intended to be given to Einstein and Planck, deeply knowledgeable in classical physics, so it'd be natural to use analogies that would be more meaningful to them than to the typical CS/EE-oriented HN reader. For example, I'd probably try to motivate the probability amplitude by detailed mathematical analogy to the wave amplitudes described by the classical wave PDEs that E. and P. knew backwards and forwards, and I don't think a concise version written that way would work as well for a typical member of the HN audience.
I believe he is referring to the 'postulates of quantum mechanics', you can find several formats from a quick google search.
Dirac, 1929:
"The fundamental laws necessary for the mathematical treatment of a large part of physics, and the whole of chemistry are thus completely known, and the difficulty lies only in the fact that application of these laws leads to equations that are too complex to be solved."
I think you can do it, but you'd probably want to start with density matrices, or use the Heisenberg picture to keep your wavefunction super-simple. If we're talking to geniuses then maybe we can include a one-off statement, 'if det ρ = 0 so ρ = ψ ψ† for some "column vector" ψ, then the squared magnitudes of ψ's components are probabilities to be in that component's corresponding state.' to get the gist of it.
I agree, but I have to say their imagination on what other things might be causing warming is not very robust.
For just one example, there are at least two major effects of burning:
1. Release of chemicals into the atmosphere (ex: carbon dioxide)
2. Directly heating the atmosphere
There are literally billions of air conditioners, heaters, cars, factories, etc that all generate heat. The effect of these billions of heaters throughout the world definitely increases global temperatures. After all, this effect is a reason why cities are warmer than their surrounding rural areas (1). This is relevant because direct heating should be temporary while greenhouse gas increases are cumulative.
Honest question - has anyone calculated the effect of the direct heating on the atmosphere from the billions of heaters we use vs greenhouse gas increase?
The primary yearly energy consumption is about 155,000 TWh and the volume of the ocean is around 1.33e9 km^3, so back of the envelop, the heat dissipated by energy consumption yearly is enough to raise the temperature of the ocean by 0.0001 C. Doesn't seem very substantial.
> this effect is the reason why cities are warmer than their surrounding rural areas.
Anthropologically produced heat is certainly a contributor, but as the article itself says, I believe the majority of the difference is more accurately attributed to the large amount of concrete in cities which takes much longer to dissipate heat.
This doesn't add much to what earlier respondents have said, but it was five minutes of fun to do.
The mass of Earth's atmosphere is about 5e18kg. Specific heat of dry air is about 1kJ/kg-°K. Total human energy consumption in 1990 (just to pick a year) was about 102,000 TWhr (3.6e20 J/TWhr. Wikipedia for most of the numbers.
Assuming all the energy consumed resolved into heat and only heated the atmosphere, then I get the one-year temperature increase due to human energy use during 1990 as about 0.073°K.
Less than I would have guessed, and probably wrong by at least a couple orders of magnitude due to simplifying away 99% of what's really happening.
What about the heating caused by ~7.5 billion humans? Collectively, we consume ~13 trillion calories, or (IIRC) enough heat to vaporize a 4-cubic mile block of ice, every day.
It's not my field, but I'd be very surprised if models were not also calibrated by extrapolating earlier known years and comparing to later known years.
You can really only judge models on days that was not yet available when they were created.
The shape of the curve is driven by the independent variable (CO2 concentration, volcanic activity, etc). The magnitude needs to get adjusted so that it doesn't produce inconsistent results when extrapolated backwards in time. Which is the problem with explaining the recent spike in temperature as anything other than CO2 concentration. Most of the other variables like solar flux are relatively steady so that if you increase their climate forcing effect you get a really bad fit in the 1900s which is non-physical.
There's also additional data like satellite measurements of the broadening of the absorption lines of CO2 and H2O in the IR blackbody spectra that the Earth radiates and the measurement of the shortfall of outgoing radiation in the radiation budget which are consistent with GHG effects and independently confirm these models.
The IPCC, probably the best source overall for climate info, has in their reports visualizations showing predictions, and I think historical results, of multiple climate models. (Sorry but I don't have time now to find links and page numbers. Try the Summaries for Policy Makers.)
Just reading their summaries, which are meticulously prepared and reviewed by hundreds of scientists, will make you more informed than 99.9% of the population, and more than most reading this thread.
Depends, overall predictions from the mid 1980's where high and a lot of research has gone into why.
A significant part of the difference disappears if you adjust for CO2 produced vs predicted. Granted, you can argue that the older models needed to account for both, but what we want to validate is predictions of impacts not predictions of fossil fuel use.
It's extremely disingenuous to show a single line as the 'prediction'. There have been plenty of projections that include possible reductions in temperature. As well as a wide range of types of measurements.
Great points. To add a little more detail, predicting the results of greenhouse gasses in the atmosephere is science. Predicting the amount of gasses in the atmosephere requires predicting human economic activity in detail (how much, in what form, etc.), which is impossible, especially on longer timescales (imagine how many investors would love to know how to do that!)
The predictions I've seen, at least in the IPCC reports,[1] show not lines but confidence intervals that widen over time.
They've not performed well based on criteria chosen by global warming denialists.
For example, you'd be hard pressed to find a climate scientist making any solid predictions about annual global temperature averages. You will, however, see predictions about decadal averages, and those have borne out.
Borne out? Compared to what? The RSS and UAH 6.0 lower troposphere predictions? What other measurements do we have that don't have uncertainty bands as large as the measurements?
And the zero trend from May 2015 extends back to 1996 for RSS and UAH 6.0.
How do you use decadal moving averages from satellite data that has only existed since 1979? You'll get roughly the same trend as the full data set. Even so, the last two decades would still be flat, or very nearly so.
We already know the full data set has a 1.2K/century trend (this is annual trend most commonly used to represent the data). Decadal moving averages aren't going to shed more light than that. We also know that if you just grab the last 19 years and 6 months, or any smaller subset of that, you'll see 0 to negative trends.
But they're the best data we have. They have the widest coverage, the least uncertainty. At nighttime the SST satellites can have over 10C of error due to cloud cover. I've no doubt the earth is warming. My doubt is that measurements with wide confidence intervals should be used over those with low confidence intervals because they tell a more compelling story.
44 Climate Models all fighting to out-panic one another, not a single one guessing low enough to predict the actual values for 2012 (when it seems the dataset in question ended)
... and a seemingly more reputable one showing roughly the same thing:
Attacking a persons 'trustworthiness' instead of dealing with their arguments and evidence is pretty much the dictionary definition of the ad-hominem diversion. It doesn't interest me to learn that he kicks cats or dresses in lingerie and calls himself Marjorie at the weekends. If you believe that he is wrong, then show where and how he is in error.
"Are you aware that Claude Pepper is known all over Washington as a shameless extrovert [pervert]? Not only that, but this man is reliably reported to practice nepotism [necrophilia] with his sister-in-law and he has a sister who was once a thespian [lesbian] in wicked New York. Worst of all, it is an established fact that Mr. Pepper, before his marriage, habitually practiced celibacy [???]."
No, because that was actually irrelevant. In this context, Soon's record within the scope of climate research is what's being scrutinized, not his personal life.
If Soon's opponents were attacking his love of Dune or his tendency to eat falafel, there might be an analogue here.
Irrelevant. The technique you used was the same as Smathers, and your intent was the same - to damage someone's reputation by insinuations and smears. It is low behavior.
Smathers' accusations related to issues that had no bearing on Peppers' merit as a political candidate or his ability to carry out his official duties. My 'insinuations' (actually, again, statements of fact) are related to Soon's behaviour within the context of climate science. If you cannot grasp this, you are not qualified to engage in debate. If you do not wish to for whatever reason, it makes it pretty clear that you are not interested in good faith discussion of this issue and are not worth anyone's time in that regard.
A damaging and false insinuation is a damaging and false insinuation, whatever ground it purports to cover. Smathers chose smears that would do the maximum damage to Pepper as a politician, you did the same for Soon as a scientist.
You can't look at someone's financial interest to know whether what they said is true or not. Similarly for any other attribute about them that you don't like.
There are many great thinkers who were gay. We don't invalidate their work because of that.
At best, you need to keep that in mind and take what they said with a grain of salt. Funding gives you a clue about which areas to be more critical about, but just because they have an interest one way or the other doesn't invalidate what they said.
If someone has been found to be a nutjob, you may casually dismiss what they said as a time saving device or because there is low probability what they say has any value to you. But even a nutjob is sometimes right.
Really? You think it doesn't matter that the primary author on a paper about climate science doesn't even have an undergraduate-level education in the subject? That the second one credited has a history of accepting large sums of money to write papers endorsing spurious claims DIRECTLY RELATING to climate change?
A lot of the IPCC lead authors are paid by NGO's (like Greenpeace) with a vested interest in climate alarmism. Do we discount their work too?
Climate science covers a lot of different areas, everything from economics, through hard chemistry and fluid dynamics, to pure statistics. No one person can be an expert on all of this, and no one qualification will make anyone competent in all of them. Experts from related disciplines are perfectly qualified to speak on "their" areas of climate science.
Are you going to tell me that every person who has ever written a paper on computer science needs to have a degree in it? While I won't question this guys qualification might be questionable - making a blanket statement that someone must be specifically educated in a subject to write a good paper on it is specious.
How often does it happen that a layman manages to get published in a well-regarded journal? Out of all the papers that laypeople publish anywhere, how many survive scrutiny from experts in the paper's problem domain? And out of those, how many that actively seek to overturn a paradigm succeed?
Based on this metric alone, it is highly unlikely that Monkcton is qualified to discuss climate change, and as it happens, his published work tends to be published by fairly obscure journals whose standards of review are questionable, and when they pass the desks of career climatologists, the result is generally unfavourable to him.
There is a difference between "layman", "well known expert in their field", "so and so with a degree in $field" "well known expert in their field with a masters in $field"
If you read my reply, I don't question the guys qualifications, I was objecting to the blanket statement of "you must have a degree in $field, to be expert" - many papers in technology, are written by people without degrees in that field.
I did read your reply; I'm saying that in the aggregate, a credible paper is unlikely to be written by someone without formal schooling in the relevant field.
Further, technology is applied science - it is not unlikely that one can become an expert through informal and professional practice. Your previous comment was about computer science, which is not necessarily the same thing, and which is closer to mathematics than anything else. Climatology is concerned primarily with physics and chemistry, but also geology and in some cases, paleontology. Most of these fields share little in common with pure maths or engineering. The comparison, then is not totally valid.
The basic training you require to be a competent scientist is hard to come by outside of academia. The actual work of science tends to be done in a laboratory. It's highly, unlikely, then, that someone who has put in the years (often decades) of work in academia to be on par with a hobbyist, whatever that may look like in this context.
Neither you nor the person you are responding to probably has the requisite qualifications to actually tell …
Judging something like this without relying on outside signals seems rather impossible and pointless if you are not, you know, an actual expert. No matter how much you want to believe you can be one about everything …
It wasn't libel the last time you brought it up and it isn't libel this time. Soon failed to disclose non-trivial amounts of funding that he received from parties who have a vested interest in deriding climate science. Given how often his work has failed to pass muster when scrutinized by climate scientists and skeptics, it is hard to fathom how any of this can amount tosimple incompetence.
The article you linked to is almost comical in its petty malevolence, well beyond the point of self-satire. This kind of character assassination, however reprehensible, is ultimately irrelevant. If you believe Dr. Wei Hock Soon is wrong, then show where and how he is mistaken.
Climate scientists have been doing that for almost 25 years at this point, and Soon's response has pretty much been to complain that he's being bullied and that science is being politicised. I find that to be actually comical, almost as much as the presumption that an intelligent and intellectually honest person could do this for as long as Soon has. And that his association with political and industrial think tanks is a non-sequitur in this regard.
The first graph on that second link is a bit confusing and seems pretty disingenuous. It has the "observations" region stretching to 2050. The rest of the article seems much more factual and interesting, but why start with something so misleading if your supposed goal is to debunk misleading projections?
Spencer is pretty out there. He's gone on record to say that warming proponents are advancing an argument that will lead to more deaths than the NSDAP's policies did, and is a signatory to the Evangelical Declaration on Climate Change, which suggests that this is largely a matter of faith for him...
He does also maintain one of the satellite records, which does show global warming over the period 1960-2000 (not so much the last 10 years because of the global warming hiatus).
Did you even read the article? look at the university of York dataset, which clearly shows the 1960-2000 warming followed by the 2000-2010 hiatus. Note the York dataset is strictly observationally independent of the UAH dataset.
Hans von Storch, professor at the Meteorological Institute of the University of Hamburg discussed this issue in a recent interview with Der Spiegel. He remarked that less than 2% of model runs reproduced the 'pause'.
SPIEGEL: Just since the turn of the millennium, humanity has emitted another 400 billion metric tons of CO2 into the atmosphere, yet temperatures haven't risen in nearly 15 years. What can explain this?
Storch: So far, no one has been able to provide a compelling answer to why climate change seems to be taking a break. We're facing a puzzle. Recent CO2 emissions have actually risen even more steeply than we feared. As a result, according to most climate models, we should have seen temperatures rise by around 0.25 degrees Celsius (0.45 degrees Fahrenheit) over the past 10 years. That hasn't happened. In fact, the increase over the last 15 years was just 0.06 degrees Celsius (0.11 degrees Fahrenheit) -- a value very close to zero. This is a serious scientific problem that the Intergovernmental Panel on Climate Change (IPCC) will have to confront when it presents its next Assessment Report late next year.
SPIEGEL: Do the computer models with which physicists simulate the future climate ever show the sort of long standstill in temperature change that we're observing right now?
Storch: Yes, but only extremely rarely. At my institute, we analyzed how often such a 15-year stagnation in global warming occurred in the simulations. The answer was: in under 2 percent of all the times we ran the simulation. In other words, over 98 percent of forecasts show CO2 emissions as high as we have had in recent years leading to more of a temperature increase.
Simple: this is exactly what you would expect on a high plateau. Think about it in terms of climbing a mountain with a fairly flat top. For a long time you're moving continuously up-slope, then when you get to the plateau you wander around randomly and frequently find outcroppings that are higher than anything you've encountered before. That doesn't mean you're still climbing, and if we were still climbing at the rate seen from 1980-2000 the "global mean temperature" (which is a thermodynamically meaningless arithmetic average) would be even higher than what we see today.
People who continually beat on extrema (like Denialists who claim that cold weather on the East Coast last winter is somehow proof that AGW isn't happening) are adding noise to the argument, not signal. The physically meaningful number is the heat content of the Earth/ocean system, and there's quite a bit of evidence it is rising, and that a significant portion of that rise is due to human activity.
This makes me think of when financial journalists/broadcasters constantly report that the SPX or the DJIA or the FTSE or whatever are hitting 'all time highs' and it's a really useless piece of information. Investors want to know how much it went up by on the day (and what he trend of the last few days/months has been), the fact that it poked through to a new high level is not important.
Apparently, the past models did not, because they did not model the long term interaction of the oceans with the atmosphere, and the current "hiatus" is mostly about the atmosphere temperatures, while most of the warming is currently happening in the oceans.
The more sophisticated current models do match the recent observations if you feed them the past data:
Yes there is! In fact, this very visualization which you are commenting on is based upon the data produced by NASA Goddard from their climate model by running a historical data prediction, as their contribution to precisely such a comparison/consensus building study sponsored by the IPCC, called the "Coupled Model Intercomparison Project Phase Five". There are links to the sources for all of this in the original article. This information, which I'm sharing with you now, is in the first three paragraphs of endnotes on the actual article.
So.... please don't believe other posters who might come along and try to get you to believe that historical comparisons haven't been performed, or the results haven't been published, or that the IPCC ignored them, or whatever else they might choose to argue today.
Even if there is a model that performs well, how do you account for survivorship bias?
And how accurate are models without a clear understanding of the physical reasons why behind them?
Seems like we should be concentrating on understanding the physical relationships and less on trying to come up with abstract models. It kind of feels like a bunch of astrologists and just picking the one that seems to perform better.
Unless I understand the why, I have a hard time accepting what anyone says.
Exactly. When modeling most data, you would hold back a validation set, but that doesn't really work as well in this situation. The only thing holding back the validation set is time.
The thing is, it's not just the temperature measurements fitting the greenhouse gases. It's also all the biological and physical evidence. Bird migrations, plant species ranges, glacier and ice cap shrinkage and growth, permafrost melting, polar vortices occurring, etc.,etc.,etc. Screw the models: look at the reality.
There's a lovely book called The Limits to Growth published in 1972, through the years authors have updated their book and their models (there's more than 20). It turned out that business-as-usual model extrapolated very well from '70s to '00s. So, even them modelling was fairly good.
Yip, great book, good warnings, of which we have done very little about. Another book to recommend is "This changes everything" ... sets out a very reasonable argument while capitalism as it stands is basically incompatible with doing much to prevent climate change. Worth a read.
Corrupt politicians will find that using environmental concerns and climate change gives them the proper motivation to say "we need more control and the common man needs fewer freedoms". This is why it's a political issue.
Don't expect masses of people to gobble up the idea that climate change is going to ruin the planet when the motivating factor for a good portion of the people selling the idea is that they can seize more control.
It's no different than terrorism and things like the Patriot Act. Terrorism is a horrible problem and no one wants armed rebels chopping people's heads off in the streets of our cities. But when politicians start their backroom meetings and connive a way to start chipping away at our freedoms and our privacy (I'm being redundant), you start finding terrorism skeptics.
We have to find the proper balance between the rights of the individual and the rights of the community. But all the while the entity that sits between the community and the individual, government, is taking more and more control. And they seem to let no opportunity to do so pass.
Climate change is one of their new, favorite vehicles.
> if you feed it data up to, say, 1990, will it correctly spit out 2015 temperatures that fit the reality of 2015, or will it spit out crazy 2015 predictions like the models that were built in 1990 did
Yeah, so they pick models until they find one that fits both 1990 and 2015? That would be using the test data to train the model - like the Baidu approach.
I have absolutely no knowledge about this field, but from what I understand people who study the Sun wouldn't agree as much with the numbers about the suns temperature.
Really, I think from what I've read, there was some talk about sun-spots, which actually lower the sun's temperature or something. I'm really not convinced that they are measuring the correct value there at all.....
This visualization is a multivariate linear regression with time trending variables...lol the entire thing is garbage, I could get a better R^2 than the 7 or so variables they used if instead I used variables to explain climate change like: number of gay marriages in the world, murders, abortions, etc...I don't recommend this, I'm just saying trended data can "say" anything
This repeats some buried comments but I think it's worthwhile: I'm not a climate scientist, but in my experience the absolute most reliable, most time-efficient way to learn about climate change is the IPCC reports. I wonder if there is anything written in any other field that compares:
Specifically, if you are short on time, read the 'Summaries for Policymakers', written at the level and attention spans of non-technical politicians. They are quite readable and as I wrote in another post, if they can understand it, so can you. :) (The longer reports are fascinating, if you have an interest in science and want to get lost in something.)
As I understand it the reports are prepared by a global team of hundreds of scientists, and reviewed by thousands more.[1] (Seriously, has anything like that existed in any other field?) They are meant to cover the breath of climate science and the reports also are meticulous about the language of probabilities.
Spend a little time reading them and it will save you the time of reading 99% of what's written elsewhere, and you'll be much better informed.
---
EDIT:
[1] Review process: http://www.ipcc.ch/activities/activities.shtml (scroll down to "The AR5 Writing and Review Process") -- for example, one report had over 50,000 comments on two drafts from >600 experts.
---
EDIT 2: Website interface help.
Can you believe this needs to be written, and for HN readers? I had JavaScript off which makes the site usable (if not pretty). With JavaScript on, apparantly the UX concept is 'Easter eggs':
There are 4 images arranged horizontally at the top; these are report covers (with text too small to read even if you knew they were clickable). If you click a report cover then the section beneath it changes to display a description of and links to that report.
All that work making the reports accessible to the world, hamstrung by web design.
A couple years back I read the IPCC reports trying to find out if global warming was real or not. I noticed the Vostok ice core data in the earlier reports showed the temperature rose first and then the CO2 rose. Likewise, the temperature fell first and then the CO2 fell later on. They fixed this little inconvenient data problem in the later reports.
> ... This statement does not tell the whole story. The initial changes in temperature during this period are explained by changes in the Earth’s orbit around the sun, which affects the amount of seasonal sunlight reaching the Earth’s surface. In the case of warming, the lag between temperature and CO2 is explained as follows: as ocean temperatures rise, oceans release CO2 into the atmosphere. In turn, this release amplifies the warming trend, leading to yet more CO2 being released. In other words, increasing CO2 levels become both the cause and effect of further warming. This positive feedback is necessary to trigger the shifts between glacials and interglacials as the effect of orbital changes is too weak to cause such variation.
In the Vostok data the temperature falls first and then the CO2 falls. If the CO2 released amplified the increased warming trend then why would the temperature suddenly reverse absent a CO2 drop?
BTW, I am really really disappointed in the quality of all the replies. It's mostly ad hominem and hand-waving. This is the one reply that's not but it doesn't explain the behavior of the drop in temperature.
Thus to sum it up:
Increased temperature causes gas to become less soluble in the ocean, thus leading to increased CO2. Decreased temperature causes CO2 to become more soluble in the ocean thus leading to decreased CO2. This data shows then that CO2 increases are not enough to cause warming all by themselves or to prevent cooling all by themselves.
Obviously a very large amount of CO2 in the atmosphere will lead to warming (e.g Venus's atmosphere is 96% CO2) but we're many orders of magnitude off from that (0.04% CO2).
So we are left with what I like to call a Listerine argument: Listerine has been selling more over the past century, Listerine prevents tooth decay, thus Listerine is the cause of the improvement in dental health over the past century. Thus we should put Listerine in the water and implement a global tax so everyone can have Listerine.
You might be interested in the opinion of Richard Muller:
In 2010, I watched one of his talks in which he had very uncharitable things to say about some groups of climate scientists and why he did not consider them trustworthy [1].
At about 34:28 of the video, you can hear him say the following:
This is why I'm now leading a study to redo all this in a totally transparent way.
He did [2].
What was his conclusion? Global warming is real, and in all likelihood the culprit is indeed CO2.
How did he come to that conclusion? Because it's the only proposed mechanism for global warming that actually fits the data on the 250y scale.
This is not an inconvenient data problem. That the ends of past ice ages were not caused by a rising atmospheric carbon dioxide concentration but instead caused it with some lag does not at all proof that a rising atmospheric carbon dioxide concentration can not cause rising atmospheric temperatures.
For example - completely made up - a change in the orbit of the earth could cause rising temperatures and therefore the end of an ice age. This could then free carbon dioxide trapped in or under the now melting snow and ice and in turn this change in the composition of the atmosphere could additionally contribute to the rising temperatures.
I'm sure the IPCC has flaws, like every other human institution (but what else do we have to work with?), but the original reports came out in 1990. Also, every data set ever produced has inconsitencies.
I don't feel that one inconsistency from 25 years ago, which might have a valid explanation or might be validly considered inconsequential, undermines the IPCC reports' credibility.
This is hardly unexpected. As water warms, the solubility of various gases decreases. I.e., if you exogenously warm up the ocean, it will release CO2 and other trace gases into the atmosphere. I'm pretty sure you could get the same pattern for Argon and other (non-greenouse) trace gases.
So, that's an interesting phenomenom, albeit one with possible explanations (that others have provided), but I'd like to volley a question back to you: have you performed the same experiments that Arrhenious[1] performed in 1896, that has been reproduced thousands of times before, and come up with a different result? (ie, that CO2 doesn't create a greenhouse effect).
Ugh. This is exactly the type of poorly-informed response you generally get when people attempt to "read the data" for themselves with little to no understanding of the science behind it. Seems to be a lot of that going around HN today.
Well, for one, that their uneducated skim through the IPCC report found a mistake which thousands of qualified scientists had missed, one so fundamental that it undermines all of the rest of the work in the report and the conclusions it leads to.
The scientists say so, therefore the commenter is wrong? This still doesn't explain why the above is wrong. Attacking the premises of an argument is sound logic, and should be welcome. Ad hominem arguments should be called out.
It's exacerbated when it's less someone reading it for themselves, than reading it in a blog post by someone who's motivated to try to strip context and mislead about results.
Your comment reminds me how the Catholic Church treated the Bible during the Middle Ages (environmentalism runs so parallel to religion it's uncanny).
The clergy would not let lay people read the Bible themselves, claiming there are "poorly-informed responses you get when people attempt to read the scripture for themselves with little to no understanding of the theology behind it."
"Just trust us," they said, "we will interpret it for you and tell you how to live accordingly."
This is a summary of research in those peer-reviewed journals, the summary being far better reviewed (by hundreds and thousands, as described) than the individual articles.
I don't know about other HN readers, but I don't have time or expertise to keep up on individual articles. I doubt many climate scientists have the expertise in all those different fields.
I'm not afraid of looking at the source.
Many times the "summaries" get distorted.
Statements like "provide some evidence for" gets translated into "this proves". Popular press often does this.
The actual raw data and original article and independent confirmation is the gold standard for science.
I've chased down many stories reporting "proof" in many fields and , after examining the actual article, found that it actually said "well, this might be some evidence for possibly maybe supporting something".
This is a hazard in MANY fields.
Many people know this.
We Hacker News readers ran in to this a couple of days ago.
Somebody said "Fasting helps in cancer therapy" and listed some science papers. It was voted up.
The actual papers DID NOT SAY THAT. They said "this small sample might provide some evidence but more study needs to be done".
These are separate things and careful readers can discern this.
Appeal to Authority or to a Mob or to Fashion is NOT science.
> Statements like "provide some evidence" for gets translated into "this proves".
For what it's worth, the IPCC reports are very, very careful about this. They have a chart (though it can be hard to find) of exactly what confidence/probability is meant by each phrasing.
EDIT: for example, from the Sythesis Summary for Policymakers report:
The following terms have been used to indicate the assessed likelihood of an outcome or a result: virtually certain 99–100% probability, very likely 90–100%, likely 66–100%, about as likely as not 33–66%, unlikely 0–33%, very unlikely 0–10%, exceptionally unlikely 0–1%. Additional terms (extremely
likely 95–100%, more likely than not >50–100%, more unlikely than likely 0–<50%, extremely unlikely 0–5%) may also be used when appropriate.
What prestige science journal article says "virtually certain" that man is primary cause of global warming?
What phrasing in the results section makes you feel that it is "near proof" ?
I'm not asking for "it is likely or probable". I'll buy that. I want solid proof ... or , uh "almost proof".
Proofs don't exist in sciences concerned with the physical world. For proofs to work in the real world, you'd need certainty that you have recognised and correctly measured every variable that could affect the outcome of an observation/experiment.
The last philosophy of science that allowed proofs was positivism. For the natural sciences, it has been replaced by critical rationalism (https://en.wikipedia.org/wiki/Critical_rationalism). CR gave a solution to the proof problem: While positive proofs like in your quote don't work, you can still falsify a theory. By continuously falsifying theory after theory about an observed outcome, something resembling truth remains. Truth, but never certainty. Hence the talk about likelihood and probability.
> I'm curious. Gravity has not been proven to attract two masses, for instance?
Correct. That's why it's called the theory of gravity :) You would need Laplace's demon (https://en.wikipedia.org/wiki/Laplace's_demon) for a proof. "Proof" means absolute certainty. You only find that in math, not in the physical world.
As he already said, science doesn't do proofs; proof is something for Math, science does evidence, nothing is ever proven. Asking a scientist for proof merely shows you don't know what science is and thus aren't capable of using it to make decisions.
> Is there any evidence that two masses don't attract ?
The answer to that question does not in any way proof the existence of gravity.
I don't mean to offend, but if you honestly ask these types of questions, I doubt you are able to evaluate the quality of original papers dealing with climate research.
Am I to understand that you'll only "bet the climate" if it's a sure thing? I'm curious to know if all important decisions you make are backed only by "virtually certain" odds that the outcome of your decision will be as you predicted.
Not trolling, honestly. I really want to better understand this mindset.
Science once labeled gay as a mental disease.
Science once said that neutrinos have no mass.
Science once thought that the universe was the Milky Way only.
"Virtual certainty" may not always be "settled science".
I do think we should curtail pollution; regardless of the scientific certainty on man as primary cause of global warming.
> Science once thought that the universe was the Milky Way only.
No it didn't.
All of those are made up facts that bear no resemblance to reality. Science doesn't say or think things, it merely shows the current state of evidence for theories and when new evidence comes along, wrong theories are disproven. That's what science does, it disproves ideas.
A scientist likely once theorized that gay was a mental disease, the process of science disproved that theory; ditto for everything else you said. You're confusing some scientists bad theories for science itself, they are entirely different things.
Yes really. That scientists had such debates proves my point, not yours. Science doesn't make absolute claims, it posits positions based on evidence and changes those positions when the evidence changes. Sadly, you're clearly not intelligent enough to understand the distinction.
Only the second and fourth paragraph of this response are "important". The rest is an attempt at clarification of my personal viewpoint. I'm doing my absolute best to not offend people on a very touchy subject - but I know it is inevitable to do so. For that, I apologize for holding a different opinion but ask that you read the entire response to understand the reasoning behind my position.
[Paragraph the second] The declassification of homosexuality as a mental disorder had more to do with harassment of the APA for several years leading up to 1973 by advocate groups than it does scientific consensus. Scientists are afraid to speak on the issue due to harassment and the possibility of losing their jobs due to said advocate groups. Even so much as trying to conduct studies on SOCE would get you harassment nowadays if the public was aware.
If we are to consider reproduction and the continuation of a species to be what is "normal" for a species (ie. the goal of a species is to produce a generation to succeed it to avoid extinction) then homosexuality is a disorder. Homosexuals cannot reproduce naturally and only through scientific advances can they choose to have a surrogate mother or a sperm donor to have a child: which is from a heterosexual process.
[Paragraph the fourth] The issue that arises of classifying it as a mental disorder is the stigma people attach to people with mental disorders. This stigma can be harmful to people and thus should be avoided. Regardless of scientific accuracy - I approve of any effort to treat people more humanely and if that means not considering a deviation from the norm to be a disorder, than so be it. I would like to point out that not all mental disorders have equivalent social stigma attached. OCD and insomnia don't tend to get someone harassed - while being anti-social or autistic is more likely to get someone harassed.
The definition of "mental disorder" is a mental condition that negatively impacts the person with the disorder. It's not clear (due to poorly conducted studies [0]) whether homosexuality is a disorder or if societal pressures are the cause of an increased number of suicides and depression. Until the social stigma goes away, I don't think we can find an answer on this. My intuition tells me that the increased amount of stress/depression/suicide are all strongly correlated with social stigma and that in more progressive and accepting regions these negative feelings are more rare. But my intuition and science don't always agree, so I've learned to not trust my intuition.
My personal views are closely related to Havelock Ellis [1].
>He proposed that being “exclusively homosexual” is to be deviant because the person is a member of a minority and therefore statistically unusual, but that society should accept that deviations from the "normal" were harmless, and maybe even valuable. Ellis believed that psychological problems arose not from homosexual acts alone, but from when someone "psychologically harms himself by fearfully limiting his own sex behavior.
TFL;DFR: It doesn't matter if it is or isn't. What matters is that society works to remove the stigma attached and treat each other humanely.
A layperson named Steve McIntyre did just that, after reading the IPCC's 3rd Assessment Report and seeing the prominently featured "Hockey Stick" based on a paper by Mann et al., and wondering, hmm... perhaps this study is reproducible?
The rabbit hole that McIntyre and his colleagues have found themselves in over the last 10 years has, in my view, demonstrated the value of hacker-types taking an interest in climate science.
"Of crucial importance here: the data for the bottom panel of Figure 6 is from a folder called CENSORED on Mann’s FTP site. He did this very experiment himself and discovered that the PCs lose their hockeystick shape when the Graybill-Idso series are removed. In so doing he discovered that the hockey stick is not a global pattern, it is driven by a flawed group of US proxies that experts do not consider valid as climate indicators. But he did not disclose this fatal weakness of his results, and it only came to light because of Stephen McIntyre’s laborious efforts."
IIRC, despite the criticsim, the 'hockey stick' study and its author were proven right. Lots of criticism doesn't make it wrong, especially in politicized debates.
You should just stop with this line of thinking. You have to understand the scientific context and the limits of the data to learn anything. (Source: I know several contributors to the IPCC AR5 report, and I try to have the proper respect for their expertise.)
Great, so you're capable of writing highly parallel cluster-scale code in C that does intensive precision numerical analysis? Most choose vectorized FORTRAN or a combination of C++ and CUDA, but hey, knock yourself out.
CERN has a 3700 core supercomputer to crunch through this kind of data. You can rent that on Amazon for about $800 an hour, so I guess you're good to go.
Sorry to be so harsh here. While there's always desirable amount of "constructive naivety" necessary to try the impossible, you need to recognize that there's considerable amounts of expertise required to process and analyze data of this complexity at scale.
This is not like a movie where six minutes of furious typing can solve any problem.
The gist of this argument is that the IPCC's members, the schools that employ them, the governments of their constituent nations, the FAO, the UN, the mainstream news media, and all administrative and custodial staff of all of these organizations are perpetrating a conspiracy to push carbon taxes on the world. Presuming the absurd scale implied herein doesn't beggar belief, the fact that the combined power of all these people has proved insufficient in bringing 'the plan' to reality ought to.
> the United Nations would be funded by such taxes
The UN does not tax anyone. They are funded by governments, which are funded by taxes.
1) By your theory, there is a confict of interest for the UN as long as anyone involved pays taxes, which covers every issue on the planet (and some in orbit, on Mars, etc.).
2) One major tax-paying industry, which has exceptional influence in government, is oil and gas. If the UN has a conflict of interest in favor of an industry, one with a long track record, I don't think I can find a better example.
You're basically saying anything funded by government that might impact economics, and thus revenues, is biased. Right..
You do realize that you can be against taxing say, income and profits, but be for taxing carbon? I think quite a few economists would agree that you tax things that you want less of. A simplified carbon tax could be a boon to business.
> You're basically saying anything funded by government that might impact economics, and thus revenues, is biased. Right.
While I don't see the now-deleted comment you're replying to, I do feel there is validity to the viewpoint that studies funded by the government can be biased in much the same way as studies funded by private companies. Government is not magically above tainting research with predisposition and prejudice.
The deleted comment said that the IPCC wants to introduce climate taxes; that the IPCC would get funded by those taxes, and thus there is a conflict of interest.
In the absence of any other context, saying "X has a conflict of interest because Y" implies "and therefore X is unlikely to be believed." Yes, presumably the UN does have a conflict of interest here. However, as Cholantesh points out, the size of the IPCC makes it unlikely that conflict is a major factor in affecting the interpretation of data (I am agnostic as to how likely the CoI is to affect the actual policy recommendations). Just pointing out the conflict, without any additional interpretation, is dodgy enough that it's reasonable to assume it's motivated by a conspiracy theory.
Helpful when reading this thread to keep in mind Michael Mann's six stages of climate change denial:
1. CO2 is not actually increasing.
2. Even if it is, the increase has no impact on the climate since there is no convincing evidence of warming.
3. Even if there is warming, it is due to natural causes.
4. Even if the warming cannot be explained by natural causes, the human impact is small, and the impact of continued greenhouse gas emissions will be minor.
5. Even if the current and future projected human effects on Earth's climate are not negligible, the changes are generally going to be good for us.
6. Whether or not the changes are going to be good for us, humans are very adept at adapting to changes; besides, it’s too late to do anything about it, and/or a technological fix is bound to come along when we really need it.
Interesting note from the l0phet article the other day regarding how fire codes and regulation in cities didn't come about even after great disaster swept the city.
Wysopal offered this grim precedent: Cities were once
vulnerable to disastrous fires, which raged through dense
clusters of mostly wooden buildings. It took a giant fire
in Chicago to spur government officials into serious
reforms, including limits on new wooden structures, a
more robust water supply for suppressing blazes and an
overhaul to the city’s fire department.
“The market didn’t solve the problem of cities burning
down,” Wysopal said, predicting that Internet security
may require a historic disaster to force change. “It
seems to me that the market isn’t really going to solve
this one on its own.”
But here’s a frightening fact: The push to create tough
new fire-safety standards did not start after the Great
Chicago Fire in 1871, which killed hundreds of people and
left 100,000 homeless. It took a second fire, nearly
three years later in 1874, to get officials in Chicago to
finally make real changes.
Though I wouldn't accept #5 and #6 exactly as phrased, it does seem like positive effects ought to be balanced against the negative, and the uncertainty of future technological developments ought to inform our current decision of how much to spend addressing climate change.
Your position is similar to that of Swedish environmentalist and academic, Bjorn Lomberg who accepts that rising CO2 levels are the cause of warming, and that this is a problem, but argues that the dangers are overstated and resources would be better devoted to mitigation of climate change and addressing other pressing issues such as global poverty.
Despite his relatively orthodox views, he was recently run off campus at the University of Western Australia where he had set up a think tank, The Consensus Centre, to which the Australian government had pledged $4 million.
Bjorn Lomborg is a sad case. He titled his book The Skeptical Environmentalist and everyone got the message, without reading the book, that he was a climate-change skeptic -- and for the most part labeled him as an "enemy" and rebuffed him. It was just a public relations disaster.
For what it's worth, he's not a "skeptic" in any of the conventional ways. I also remember looking at the IPCC reports once when I was a young physics student and saying, "hey, it's only a couple degrees Celsius over many years?" I was educated enough to realize that you could predict bad storms etc -- what I like to tell people right now is that it's like having a really huge boulder and, right next to it, digging a little ditch, only to cause the boulder to smack you down: the small change in the height of an equilibrium can still have a huge effect if a big enough system is relaxing to the new equilibrium. Someone came up with a memorable name for it: it's less of a concern about "global warming" and more about "global weirding." It took me a while to appreciate that there is a small (but scary) probability that the slope that the boulder is on might have a net incline one or the other way, so that the boulder might not just hit us but roll over us if it gets disturbed far enough from equilibrium. It makes a lot of sense for there to be a big scientific research program about that, even though no IPCC model predicts runaway climate change because the probability is so low and the possible causes are typically unexpected.
With that said: though hurricanes, floods and tornadoes certainly can have a massive economic impact, Bjorn has a good point of "the weather disasters that we know will happen due to the warming that we know is happening are important, but let's figure out how this compares to other things which we can predict really well, and see where our money is best spent: climate-change relief efforts, or climate-change mitigation, or general alleviation of poverty, or what?"
What I think is most missing from all of this is: we're talking about so little money, especially if we compare to governments' military expenditures, going towards the science. What would be great is if a government said, "hey, we're putting forward this huge grant to climate change research just because we think research is intrinsically good and want to support this huge project of, y'know, knowing more."
I am quite happy saying, "Climate change is a plausibly serious problem and the current best solution is to build nuclear (fission) power plants today to replace base load coal, to shift from income taxes to carbon taxes and tarifs immediately, to build solar power and storage immediately, and to phase in regulations that will make it essentially impossible for new thermal coal development. We should also have public subsidies for nuclear and solar to ensure rapid deployment."
When I say that I fequently get called a climate change denier, because that is a label used primarily (not exclusively) by people whose primary goal is smashing global capitalism, and who find climate change a useful stick to beat their political enemies with.
> We should also have public subsidies for nuclear and solar to ensure rapid deployment."
Can you elaborate on the relation between the nuclear energy industry and insurance companies? Even as someone who sympathizes with the goal of "smashing global capitalism," I would find it interesting to know what the free market has to say in this respect.
It's important to understand that if we completely shut off CO2 production today, the climate would continue to warm significantly for decades/centuries into the future. And that warming might not be completely catastrophic, and could even seem positive in some ways to a minority of world citizens. The 350ppm of 350.org is still way above pre-industrial levels, but is seen by most as safe.
However, that's no longer what anyone is arguing about. What is argued about is the continued effect of dumping 40 billion tons of CO2 into the atmosphere year after year after year with no end in sight, while we're already over 400ppm. Any arguable positive effect, we've already achieved - it's the 4-5C of warming we're currently on track for that scientists claim, with good reason, will be catastrophic for human civilization and the present state of life on earth.
You're certainly not denying climate change, but maybe you're someone who doesn't care about the impact, as long as humanity survives. And why should we care? There are so many reasons not to care.
- We're out of touch with nature.
- Even for those in touch with nature, the human scale is too short to personally see and feel any change.
- The individual's responsibility is extremely diluted with the rest of humanity.
It will sound cheesy, but I care because of the beauty of nature. An extinction event is something that destroys biodiversity, and biodiversity is the source of this beauty as I feel it. Maybe the diversity of life will return in another form a few million years later (and maybe not), but simply understanding the act of destruction that is underway does impact me emotionally, and makes me want to stop it.
> and the uncertainty of future technological developments ought to inform our current decision of how much to spend addressing climate change.
Well, that does not necessarily sound like something the author of the grandparent comment would disagree with, especially when you consider that the technological developments may not universally be regarded as solutions (e.g. geoengineering).
The first four stages have always baffled me. Anyone who knows basic chemistry understands how carbon dioxide interacts with infrared radiation. Combine that with the fact that human activity is releasing tens of billions of tons of CO2 every year, which does not magically disappear. In fact, it's quite measurable.
The climate is complex, but the basic facts of the situation are incredibly simple and unavoidable. And yet, people have still tried.
Indeed, I studied chemistry and certainly believe that carbon dioxide interacts with infrared radiation, but actually understanding that process is a totally different story.
What I don't like about "my side" of the climate change conversation is that it so often underestimates the difficulty and time investment necessary to really understand this stuff, and in so doing, disrespects people who aren't scientists. Is it any wonder then, that those people turn to the side that is willing to put things in terms they understand instead of making them feel stupid?
We need more Carl Sagan types; people who recognize that their years of scientific study have put them in a position to understand things that vanishingly few people can even conceptualize, and make it their work to educate rather than condescend.
Another interesting tidbit: You'll find this on both sides of most public discussions I guess.
A whole lot of the people who tries to defend man made global warming in public forums seems to be parroting what they have heard, just like the naysayers.
Getting to the facts instead of gettings served up brochures seems hard and asking questions gets you smacked down by a bunch of zealots.
Which is why I found this piece interesting: at least some numbers and charts that seems understandable.
Lots of people across broad spectrums do this all the time. It's uncomfortable to publicly admit you don't know something; a lot of people, especially otherwise smart people, try to apply their expertise in one area to another area they have no specialized knowledge in.
Programmers as a group are maybe a little bit worse about this than most other groups (except maybe physicists), because they view themselves as "systems people", and "everything is a system", therefore similar rules apply everywhere: software is buggy by nature, so scientific research must suffer from similar error rates, for example.
Well, a lot of people argue that the moon landing was a hoax (without knowing basic engineering) and that the holocaust didn't happen (without knowing basic history). I find it more depressing than baffling.
Well, carbon dioxide's interaction with infrared radiation would be more studied by physics than chemistry.
Also, I kind of hate these types of statements. I could say something like, "Anybody that knows anything about music should know that parallel minor of A Major is F# minor," but it's not like I would be adding anything to any discussion by saying such.
I don't think the general population is thinking about it that much. To me, the main denial seems to be a dislike and/or distrust of the people advocating the AGW theory.
For example, having Al Gore as a prominent figure of the AGW theory movement for a number of years is enough to make them suspicious. They see him fly in private jets, own multiple humongous homes, make investments that will pay off if things like carbon credits become mainstream, release a movie 9 months after Katrina that promised more and more severe hurricanes that never materialized, etc, etc. He might not be a duck but he sure seems to quack a lot.
The other main denial seems to be things like, "It's cold today - in your face global warming".
I think Michael Mann is giving people far too much credit.
There's also the pretty standard *these scientists' intuitions about causal links between human activity, atmospheric CO^2 and recorded temperature might well be right. But you're not convincing me to pay carbon taxes or cycle. Which is less unreasonable than it sounds when you consider the evidence of human ability to slow or reverse climate change (at all, never mind through eyecatching civic initiatives) is in rather shorter supply than the evidence of human ability to adapt to climate change.
Please don't take this as a denial of climate change, it is an honest question. How do scientists learn the levels of ozone, aerosols, green house gases, and the other data points going so far back at a global scale? Is the data from before the latter half of the 20th century spotty? If so, why is it considered good enough to use in a context of scientific research where quality and correctness of data is paramount?
They use so-called "proxy data". You measure something else that has been accumulated and preserved over time and that somehow correlates. You have to create a model, fit it so it correlates with recent measures and you are done.
Level of oxygen for example can be estimated from layers of ice. Mann used tree slice(s) for temperature estimation.
There's a lot of problems with proxy data and their models and there is a lot of space for scientific misdemeanor. Some journals recently started to require a full disclosure of all data and models on which they base their claims, which - surprisingly - isn't always the case.
As more data is gathered over time some models need to be adjusted. How much they need to be adjusted reflects quality of the model.
It's a serious problem in multiple areas in society these days; the inability to ask simple questions that may go against the "accepted" narrative without being personally attacked. Science, religion, politics, sports, it's everywhere.
It's a seriously sad state of affairs, but nothing new really, if you think about it. The reach of modern communications has inflated the problem in my opinion.
Here's the thing: honest enquiry is something that should be encouraged. Sea-lioning[1], JAQing off[2] and Gish gallops[3] should not. When you are buried to your eyeballs in bullshit, it's hard to see who is really someone willing learn, and who is just shoveling on more.
It boggles my mind that people use the term sealioning unironically. How can it possibly be that a sensible person thinks it's ok to make a hateful statement in a public place and when someone asks clarification about it they are the harassers?!
You are not a priest preaching to the ignorant congregation, if you don't want to deal with the bullshit get off the fucking podium.
Here's my sealion of a question. What parts of climate change research are actually backed up by the scientific method (experiments with falsifiable hypotheses and all that) and what parts are more akin to natural history or something else? To clarify, I believe humans caused the problem (it appears that stating this makes people like you more, which is weird, but ok) but I cringe every time I hear the word science attached to the debate. Is it like a social science? I think someone told me that we know for sure that greenhouse gas emissions cause ozone depletion but I can't remember anymore. What is the actual hard science here?
>What parts of climate change research are actually backed up by the scientific method (experiments with falsifiable hypotheses and all that) and what parts are more akin to natural history or something else?
I do not generally get involved in the climate change debate because it has multiple problems: it happens on scales (both time and space) that humans have difficulty observing, it is about a system with lots of feedback that could very well behave chaotically, direct observations of the phenomenon are limited compared to its timescale, experts of the subject are operating under perverse incentives, it is highly politicized and almost everything that's easy to read about the subject is blatant propaganda (see all the climate change denialist posted in this thread as well as the OP).
Your question is hard to answer because it assumes there is a shared and agreed upon definition of the word "science" that can be used to determine with certainty wethere something is science or not.
> Is it like a social science? I think someone told me that we know for sure that greenhouse gas emissions cause ozone depletion but I can't remember anymore. What is the actual hard science here?
I think it is in better shape than the average social science, the greenhouse effect and the ozone depletion are two separate phenomena, this [1] is the experiment that explains how the greenhouse effect works, the wikipedia page about ozone depletion explains the chemical reactions that lead to that.
1) You can't tell whether someone is "just asking questions" in good faith or not.
2) Dismissing a horde of people all raising the same problems with one's beliefs as "sealions" is a tempting shortcut to actually examining one's beliefs, which might in fact be wrong.
So the answer is to assume that everyone is pulling your chain in an effort piss you off with their bullshit? That is a prime example as to why I see all this as really sad. If one can't handle the bullshit, perceived or real, slung out in public discourse then maybe one shouldn't participate in the public discourse about that particular topic. Because most likely these are the type people who sling their own bullshit disguised as truth.
My memories of a debate, especially a scientific debate, was that both sides presented their best evidence to determine a likely winner. These days it seems the easiest way to win a debate is to insult the other side enough so that they shut up. If someone uses that tactic in a debate I immediately question the validity of their viewpoint; because it seems they question it themselves and are not willing to admit it.
Good question. I know of one way, which is to look at sedement and other physical evidence that is laid down gradually over time. For example, tree rings (of trees hundreds or thousands of years old, or maybe even petrified trees) and ice cores (for example, from Antartica; the chemical composition of the ice and the air trapped in it depends on the prevailing environment). As I understand it, your question has received much attention over the years and these techniques are mature and well-developed.
To understand these issues and much more, I highly recommend spend a little time on the IPCC reports:
They don't for aerosols/ozone past the 50s I dont think.
But carbon/methane/NO/etc... they get from ice samples that have trapped air bubbles from quite a long time ago. They also take a ton of samples from ice cores and the data is reproducible both in the north and south poles. I believe temperature is also learned from the ice samples.
Its either directly measured or inferred. Ice cores, lake bottom cores, old wood cores. The error bars are wider for some, I'm sure, but that's accounted for in the models, to degrees of course.
"Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, an inherent variability in global climate, or decreases in the human population."
It seems we don't even know how the little ice age happened. How do we know these same forces aren't changing our environment now?
We've been having all these strange temperatures lately and also this:
The problem is that it's too political now. When claimed scientists are coming out and saying the science is "settled", I know we have a problem. Science is never really settled.
Remember that's a well-documented, established technique often used by people who want to obstruct things; create so much noise (as in signal-to-noise) and FUD (Fear, uncertainty, and doubt) as to confuse the public about the facts. In every field, you always can find someone to say anything on TV; heck, you can find tax attorneys who will say you don't have to pay income tax (good luck with that!).
> When claimed scientists are coming out and saying the science is "settled", I know we have a problem. Science is never really settled.
'Settled science' is jargon; it distinguishes theories that are still up in the air (string theory) from theories that have proven themselves as very reliable (gravity). Nothing in the world is ever "settled", but the evidence is pretty certain about climate change:
IIRC, 97% of climate scientists believe it's happening and caused by humans; the US National Academies of Science agree, as does the Royal Society in the UK; the US defense and intelligence communities are planning on it, as is the insurance and other industries. Sure, they all could be wrong, but so could the deniers. Who seems like a better bet, the 3%, or the 97%?
It's become a politicized issue, and as such, the media has created a narrative of 2 sides and a "debate." Take the 97% and put it into a different context and it makes the situation seem absolutely ludicrous.
If you had a sore stomach, and asked 2 groups of people to help you figure out why, would you trust the diagnosis from a group with 100 world-class doctors, surgeons, dieticians, etc... or 100 random people? When the random people say "Ya, but the doctor's don't know anything"... why would you believe them?
We've got global consensus from the leading experts in a dozen or so related fields, all pointing to the same thing. I trust the people that landed on the moon and can launch satellites to space to give me better information about the Earth's macro trends than the guy next door that uses his bible and the cold weather last week as his evidence of a trend.
Your medical example has happened before. And, it gives us the answer! People will believe the people who have better access to the media, which, in this case, was tobacco companies hiring hacks to push a certain line of evidence demanding that the media teach the debate and give equal time. And as a result we got hundreds of thousands of excess deaths.
Ironically, many of the same tobacco-cancer link deniers are now working in the service of the global warming denialist bloc. I guess oil barons pay better than southern planters.
>If you had a sore stomach, and asked 2 groups of people to help you figure out why, would you trust the diagnosis from a group with 100 world-class doctors, surgeons, dieticians, etc... or 100 random people?
Not unless two of those 100 random individuals were Barry Marshall and Robin Warren and the stomach pain was due to a peptic ulcer.
"Marshall and Robin Warren showed that the bacterium Helicobacter pylori (H. pylori) is the cause of most peptic ulcers, reversing decades of medical doctrine holding that ulcers were caused by stress, spicy foods, and too much acid."
The point being that a reasonable belief long held by experts was shown to be false by careful scientific investigation. That said, I don't find this kind of meta-rhetoric helpful as it serves only to steer attention away from the pertinent matter at hand and to shut down discussion.
I get what you're saying, but Marshall was a doctor. He'd be in the 3% of the group of informed scientists that are working to figure out this scenario. My point is that the general public's opinion and perception of the issue shouldn't carry as much weight as the experts.
Apologies to anyone basing their beliefs on religious faith or personal experience. That's your choice, and unfair for me to judge.
As for straw man, I don't think that's technically correct, but it's a hard point to make without analogy.
Conventional wisdom is (I believe the majority of people are under the impression) that there's actually a scientific debate about this, and that the scientists and climatologists are all bickering about the causes. That's not the case, but we're largely ignoring that because the media and a few opposing scientists are casting doubt.
> IIRC, 97% of climate scientists believe it's happening and caused by humans
No, you didn't recall correctly. It's published papers taking a position on AGW and even that number is questionable at best:
To manufacture their misleading asserted consensus, Cook and his colleagues also misclassified various papers as taking “no position” on human-caused global warming. When Cook and his colleagues determined a paper took no position on the issue, they simply pretended, for the purpose of their 97-percent claim, that the paper did not exist.
Morner, a sea level scientist, told Popular Technology that Cook classifying one of his papers as “no position” was “Certainly not correct and certainly misleading. The paper is strongly against AGW [anthropogenic global warming], and documents its absence in the sea level observational facts. Also, it invalidates the mode of sea level handling by the IPCC.”
"IIRC, 97% of climate scientists believe it's happening and caused by humans"
Okay, show me a study that has the details on which parts are human made and which parts are caused by nature (with numbers). I have never seen this anywhere and You would think if they actually knew, we would have seen it by now. This isn't that difficult and it doesn't really make any sense that humans are causing 100%. Especially with things like the little ice age before we were around to pollute the earth.
"the US National Academies of Science agree, as does the Royal Society in the UK; the US defense and intelligence communities are planning on it, as is the insurance and other industries. Sure, they all could be wrong, but so could the deniers. Who seems like a better bet, the 3%, or the 97%?"
Well, if we are going to use this argument, we could very well think the solar system revolves around the earth rather than the sun.
What about our treatment of women and minorities? Everyone did it, so it MUST be the correct behavior..right?
How about smoking? Even Doctors promoted it at the time (they are experts, right?).
Being homosexual and transgender was seen as a mental illness for decades. But all the experts agreed, so it must again be correct, right?
I guess it is a mental illness!! The experts all agreed..I can't go against them..
Even more recently, "Hands up don't shoot". Forensic evidence came out and said that it never happened, yet we have mainstream media and seemingly intelligent people continuing on with the stretching of the truth to fit a narrative.
"but the evidence is pretty certain about climate change"
Yes, the climate is changing (a fact). But we still don't know if it's completely due to man-made changes or nature.
You also left out government funding and the politics around academia, which is very important when it comes to studies. It's pretty well known in the academic world that if you don't support the current narrative, you will not get funding.
I worked for many years in Academia and it's 99% politics if you want to actually get funding. If someone in a higher position doesn't like you for any reason, you can kiss it goodbye.
Climate change (also known as Global warming and Global cooling depending on what the new narrative is for the day) has been talked about since the 1970s. None of the predictions by scientists at that time came even close to true and it was a majority..just like today.
Science shouldn't be about trying to fit the evidence to a narrative. It should be trying to figure out the truth.
If you can't even debate me on these simple questions, how can I ever believe what you are saying is true?
Even the behavior here on HN is pretty telling. I ask a few questions and I am met with: hostility, anger, and people using words like "fucking". If it is this bad here, I can't imagine the climate scientists with contrary evidence. It's just like during the middle ages. Except they won't be burned at the stake, they will lose their careers.
You claim to be interested in the science, yet you reject what the overwhelming majority of scientists have to say, and only quote people who have no experience or expertise in the topic area and who produce very many innaccurate statements, which all get rapidly debunked. But because you reject science you ignore the debunking.
Well, it's much worse than that. It is not true that 97% of scientists agree with AGW theory. That claim is a lie, based on the paper by Cook, et al. That paper was a premeditated fraud. But people are still perpetrating the lie about consensus. The media loudly announced the claim, but the media has ignored the uncovering of the conspiracy. Of course, anyone can google it, if they want to...
So, you have 1) the consensus claim shown to be a lie, and 2) the IPCC shown to be telling scientists to deceive the public.
Either of those facts alone should sink the AGW movement. But it's hard to get the truth out to people who don't care enough to look it up themselves, because the media is invested into the false narrative.
"Honestly dude, do the fucking research. Read the IPCC. Hell even Wikipedia has the fundamentals extremely well explained. We know very, stupid well what's causing the climate to change. CO2 concentration is not just a correlation in the models, but has a directly observable physical effect that has been known about in labs and was later shown to be the primary reason for global warming."
It's interesting that we had a major climate change before the industrial revolution and we still don't underestand completely how it happened.
Maybe I'm just smarter than most climate scientists? After all the number fudging that has happened in the last few weeks (and during climate gate), I think it might just be the case.
>Again, "Do the fucking research" is not a debate.
Why do you want to debate instead of learn? Why not go read the IPCC report in which your questions are likely to be answered? Don't count on the lay interest of HN commentators, go read what the experts have to say directly. That's what that report is for.
>It's interesting that we had a major climate change before the industrial revolution and we still don't underestand completely how it happened.
We have a pretty good guess. Native Americans suddenly lost 95% of their population due to plagues introduced from Europe. They in turn stopped burning the forests of the Eastern US. The forests recovered, and pulled a huge amount of carbon out of the air. This caused an ice age.
I do learn. I learn by looking at all evidence and facts rather than just the ones that tell me what I want to hear. Even when it's been shown that evidence has been doctored (like during Climate gate and more recently with the temperature readings), it's just explained away to further write the narrative that man has caused Climate change and anybody that questions it is considered a kook. THIS ISN'T SCIENCE NO MATTER HOW MANY BLOGS AND WEBSITES SAY IT IS!!!!
The pope talked about it last week during his speech. He mentioned climate change, but he also mentioned that abortion is wrong (and hurting the environment) and that people that are transgender are against god.
Which part do you think the media picked up on?
The Left in the US has been demonizing religion for many years..especially the pope due to many anti-science beliefs. Now, because he happens to fit the narrative, he's talked about in those same communities like we should listen.
Since there isn't really any scientific basis for his opinion, it really makes me wonder about many of the other "studies" going around the Internet.
I've done research on many of the people that claim to be a 'Climate scientist' and most aren't even close.
"They in turn stopped burning the forests of the Eastern US. The forests recovered, and pulled a huge amount of carbon out of the air. This caused an ice age."
So there are other reasons why the climate changed.
Actually, all of the other comments to my post did it for me. I'm curious why seemingly intelligent people can be so easily manipulated by biased studies. Maybe it's the fire and brimstone articles.
Al gore knew this and is now a Billionaire because of it. He even tried to get the government to force entire industries to buy carbon credits from his companies. Nobody cared about this. Not even in the scientific community.
He was the one that championed the idea of "Global warming" and the scientific community followed it..even when he said foolish things like the science is "settled". I've heard this repeated over and over again. It's not..and if you say this, it's not science.
Even here on HN, anything said against him was down voted. If bullshit like this can be passed off as the truth, it again should make everyone question it.
How do you think the IPCC gets funded? Do you honestly think they would publish a report that bites the hand that feeds them? We need more independent studies.
If this were a big corporation funding a study on Climate change and it didn't fit the narrative, this is exactly what you would be saying.
When Money and Politics gets involved, the facts get muddied and hidden.
>The IPCC receives funding from UNEP, WMO, and its own Trust Fund for which it solicits contributions from governments. Its secretariat is hosted by the WMO, in Geneva.
What interest do these organizations have in inaccurate science? How could they possibly be more neutral?
"What interest do these organizations have in inaccurate science? How could they possibly be more neutral?"
If climate change is not man-made, they will no longer get funded. It's just as biased as any big company doing the same research, but it's excused because it's somehow seen as more 'scientific'
I can see through most of the political BS that people even here on HN can't seem to grasp. Why is that?
I am a little older and more experienced, that might be it. But I shouldn't really be that surprised from a community that willingly rallies around ideas that continues to subjugate them.
It puts me about 10 steps ahead of the majority of people.
> I can see through most of the political BS that people even here on HN can't seem to grasp. Why is that?
It isn't, you simply believe that it is; as the guy below said a clear case of Dunning Kruger, you are vastly overestimating your own intelligence. You've done nothing here but repeat plainly ignorant right wing propaganda that's not even smart enough to require disproving.
"Conversely, highly skilled individuals tend to underestimate their relative competence, erroneously assuming that tasks which are easy for them are also easy for others"
Going a bit grey isn't being "immediately silenced". People can still read your comment.
I think you're reading too much into the "the science is settled" comment. It's a field where powerful interests work aggressively to discredit a majority view of scientists, and it's likely that some (magnified by the media) may use a term like that out of frustration to imply consensus and a wish to have policy makers progress on action.
I know it's easy to find an aberration on Wikipedia, but the pros know all that stuff, they live it every minute of the day.
I disagree with your points on climate science, but I do agree there's a bit of overreaction to what could be honest questions. However maybe this explains the response:
* Your questions do seem a little like assertions with question marks at the end, because they repeat some climate denial propaganda. In fairness, maybe that's all you've read (Suggestion: Don't get your climate science from mainstream media that is at all politicized (e.g., most UK newspapers, Fox, Huffington Post, etc.) It's a waste of time and misinformation. Try Nature (nature.com), Science (sciencemag.org), New Scientist, Scientific American; even the NY Times is better, though IME very incomplete).
* Many of the questions are easily answered with a little research, which make them look more like assertions and not like questions from someone interested in learning.
* Unfortunately, easily researched questions that repeat inflamatory propaganda don't add much to the conversation.
Perhaps on a less inflamatory subject, where others were less tired of propaganda and less concerned with it taking over the conversation, nobody would have downvoted you.
As someone who definitely doesn't agree with the mainstream opinion about all this, it comes across as fundamentally un-serious when you casually refer to the opposing argument as "propaganda" without any elaboration. I've used that kind of rhetoric probably too often and it is counterproductive. If you are genuinely interested in communicating what you believe to be good information to those who don't agree, please consider avoiding that kind of language.
I generally agree, but at the same time I'm not going to create a false equivalency. A significant portion of climate change denial is, in fact, a propaganda campaign. The points are not fact or information, but propaganda. Still, I could have and should have phrased it in a less inflamatory manner. Thanks for the reminder.
Some advice: there is definitely an acceptable way to challenge the mainstream here, but I don't think you've succeeded at it. Since all of your points have appeared here before, my suggestion is not to make them all at once (which encourages people who disagree with you not to bother responding and just to downvote) but rather to pick one or two of the most relevant points and back them up with extreme detail, meaning more than a link to Wikipedia.
For example, if we're talking about the proxy studies, you can mention how central they are to the larger debate and then go into detail about the long history of problems like the short-centered PC analysis in at least one of the MBH papers, or Briffa's divergence problem, or more recently the all-but-retracted Marcott paper.
Or alternatively, respond to someone claiming that the skeptics are completely responsible for politicizing the subject by pointing out that since the alarmists are demanding all the change, action, new laws etc, there is a very significant burden of proof on their shoulders. Then say that claiming "the science is settled" so they can skip to the legislation is very much why the subject is so politicized today.
And unfortunately, no community can completely avoid politics and groupthink at all times. So if you see a large number of people who seem like they will violently disagree with any but the most tactful of arguments then you can always just let them have their echo chamber and move on.
"And unfortunately, no community can completely avoid politics and groupthink at all times. So if you see a large number of people who seem like they will violently disagree with any but the most tactful of arguments then you can always just let them have their echo chamber and move on."
This was my entire point of posting everything, and the HN community made it quite nicely: real science can't be accomplished because group think and politics are getting in the way.
Silencing political opinions (this has become a political opinion now) is never the answer.
Thanks HN, I just wanted to thank you all for making my point for me, so I didn't really need to.
Apart from the rhetorical strategy, the only other suggestion is just to be polite and edit out as much snark as you can do without, like for example that last paragraph. You may find that people here are more welcoming of (tactful) contrarian and minority viewpoints than your average internet place, although they do like a lively argument.
Given that the essay links approvingly to Crichton's Aliens Cause Global Warming address, I think you might understand it better if you read the whole thing again.
It's worth keeping in mind that the modeled data lines up with reality because it's supposed to. That's how you calibrate your model, by making sure it fits reality.
The real trick is to see how well your model extrapolates from the data you have out into the future. As in, if you feed it data up to, say, 1990, will it correctly spit out 2015 temperatures that fit the reality of 2015, or will it spit out crazy 2015 predictions like the models that were built in 1990 did. And, the bigger question: How will its predictions for 2040 (given 2015 data) match up to the reality over the next 25 years.
We seem to be getting a lot better at the modeling side. That's a good thing, since the first couple decades of watching people panicking and fighting each other over whatever scary results came out of the first generation climate models wasn't any fun to watch.