The hockey stick is probably the most famous evidence championed by those that support man made global warming. This is for one very good reason: it is almost completely undeniable. For this reason, most of the scientific community has reached a consensus.
WHAT IS THE HOCKEY STICK?
The hockey stick is a graph of average annual temperature against the year going back about 1000 years. It is called a hockey stick because it seems reasonably constant (see later) until the industrial revolution when it shoots up giving the graph the appearence of a hockey stick.
WHY IS THE HOCKEY STICK SO CONCLUSIVE?
The hockey stick on it's own shows nothing. It's only when scientists tried explaining the hockey stick graph that man made global warming became undeniable.
As is common in science, the first step is to consider all the possible factors that could influence global temeratures. Scientists found the following (I think it covers all of them but I might have forgotten one): the sun, including sun spots, solar storms and other solar activities; valcano's; carbon dioxide emmissions.
The next stage was to figure out how each of these factors effect our environment. This is where the hard science came in.
Stage 3 is using the knowledge from stage 2 to plot a graph of what the temperatures should have been given only those 3 factors. This requires heavy computer simulation.
When they included all the factors but for man made CO2 emisions, you get a graph which works very well except for the last 100 years or so.
Using the natural factors (the sun and valcanos) the model's predicted a medieval warm period (in the 1400s or something) and also the mini Ice age in the 1700s or something. It also predicted a new warm period for what is happening now. But although this graph predicted the actual values of the mini ice age and the medieval warm period extremely accurately, it was far too low to explain the size of the hockey stick in the last the years.
Now add CO2. The simulation again (not surprisingly as there were no CO2 emmissions before the industrial revolution) shows the mini ice age and the medieval warm periods. But now, their is a hockey stick almost idential to the one we have actually measured.
WHAT DOES THIS MEAN.
Natural factors do suggest we should be going through a warm period. But as is common with science, when we add figures, they simply cannot explain the shear extent of temperature rises today.
It is only when we add CO2 emmissions that today's temperatures can be accurately explained.
GLOBAL WARMING SWINDLE, THE FRAUD
Global warming swindle made out falsly that the hockey stick graph has been altered to show no previous variations (ie the mini ice age and the medieval warm period). It accuses climate scientists of deliberaly ignoring these two natural climatic events. But this couldn't be further from the truth.
Scientists, far from ignoring them, it is only because of these events that the hockey stick is such strong evidence of man made global warming. This is because natural warming accounts so well for those climatic events, but is completely incapable of explaining today's warming without considering man made CO2 as well.
WHAT ABOUT GLOBAL DIMMING?
Not much to do with the hockey stick, but dirty burning of fossil fuels has also caused global dimming. This has caused world wide levels of sunlight to be decreased and this COOLS down the planet. Yet the planet is still heating. How can this be? Because the degree of global warming is significantly higher than any of us realised a few years ago and global dimming only masks us from the true damage that we are doing right now to our environment.
As soon as we start burning more efficiently in other areas of the world, global dimming will go and our planet will feel the full force of global warming.
WHAT ARE THE STAKES OF GETTING IT WRONG?
Scientists predict that if the temperatures rise over 10 degrees, the entire sea will release so much methane gas (a green house gas 100 times more effective than CO2) that our environment could turn into one like Venus: almost completely uninhabitable.
SO IS THERE ANY DEBATE?
Well yes. There is debate. Will global warming, if it continues as it is now, completely destroy our planet in 150 years or will it take 500 years. That is what scientists are trying to find out now.
Are we at the point where the artic ice caps melt irreversibly? We don't know. Debate. How many years until the Amazon dies? We don't know that fully either. And then how much time until that doomsday senario of the methane release from the sea? Again, don't know. Debate. Lots of debate.
But not a single honest part of it is about whether man made global warming exists. Science has moved on from that. It's happening people.
I hate it when people use terms like 'undeniable' over things that indeed CAN be denied.
Hell....we have a whole new science of 'Exobiology' which is based around claims that it is 'undeniable' that there must be other life out there. Well, I hate to ruin a lot of new jobs but such claim most certainly is deniable. There is not a scrap of evidence that life ever evolved anywhere else. But the uncertainty keeps Seth Shostak and Jill Tarter ( and the rest of the SETI team ) in a job......same as the uncertainty over CO2 warming keeps climate scientists in a job.
And so it goes for CO2 based global warming, which frankly is based on evidence about as tenuous as Carl Sagan using Drake's equation to come up with 10,000 other civilizations out there ( Hmmmm......I wonder were they all are !).
The analogy with Drake's equation is a good one. Drake's equation is itself a good statistical formula. BUT....the results you get out depend entirely on the factors you put in. Many of those factors are unknown. Sound familiar ?? Well of course, its no diferent with the infamous 'computer models' for global warming.
Just as you can get a million, or only 10, civilizations out of Drake's equation.....so you find that 'computer models' predict a rise of anywhere from 0.5 degrees to 10 degrees.
So it comes as no great surprise that tweaking a few values in some simulation you can get a simulation of the infamous 'hockey stick'. None of which constitutes scientific evidence that you have tweaked the right values. All it says is that there's a parameter in there somewhere ( or maybe even not in the simulation at all ) that can be tweaked to give a result that looks like the temperature graph . But I've seen days when the FTSE Index looked like a hockey stick graph........and I doubt the London Stock Exchange is causing global warming ( at least not directly ).
All the stuff about ending up like Venus is just so much ridiculous alarmism. The greenhouse on Venus is largely the result of lack of techtonic activity that would subduct carbons as with the carbon cycle on Earth. The atmosphere on Venus is 96% carbon dioxide.....compared with only 0.03% on Earth.
So it comes as no great surprise that tweaking a few values in some simulation you can get a simulation of the infamous 'hockey stick'. None of which constitutes scientific evidence that you have tweaked the right values. All it says is that there's a parameter in there somewhere ( or maybe even not in the simulation at all ) that can be tweaked to give a result that looks like the temperature graph . But I've seen days when the FTSE Index looked like a hockey stick graph........and I doubt the London Stock Exchange is causing global warming ( at least not directly ).
With respect, I'm not sure you have really experienced the power of these computer simulations.
It's not a huge number of variables randomly put in. They use the laws of physics to calculate what must happen and the variables are mostly known. There will be some variables that can be tweaked that is true, some unknowns. But it is impossible to get a simulation predicting the graph as accurately as they did unless that simulation is an accurate calculation of the laws of Physics applied on Earth.
It doesn't just 'look' like the recorded results, it IS the recorded results.
Your point about the FTSE index does make some sense. It is true that you can select a small section of the FTSE index and make it look like anything. You could also get a 'predictor' and for a small section, it would look right even though both will be random.
But that is not what is happening here. Here, we have every single data point ever recorded going back a thousand years and the simulations can account for every single year almost bang on.
Quite simply, your calous disregard of evidence produced by computer simulations is logically, intellectually and most importantaly of all, scientifically not credible.
I would say "not credible in my view" rather than just "not credible", but it's not really my view, it's scientific fact: computer simulations are good science.
quote:
All the stuff about ending up like Venus is just so much ridiculous alarmism. The greenhouse on Venus is largely the result of lack of techtonic activity that would subduct carbons as with the carbon cycle on Earth. The atmosphere on Venus is 96% carbon dioxide.....compared with only 0.03% on Earth.
What I said is that if the methane leaks out of the oceans, then our atmosphere will be similar to that of Venus. And methane will leak out of the rocks if sea temperatures rise by something in the order of 10 degrees.
Well....maybe I don't trust computer simulations because I've spent 20 years actually working with computers. What you get out of a computer similation is just exactly what you put into it. The infamous example of Deep Thought in Hitchhiker's Guide.....coming back with the answer 42.....is not far from the reality of such things.
Consider similar models for planetary formation. For years scientists were convinced of the standard 'accretion' model....as it explains our particular solar system so well, and it comes out very nicely in computer simulations. And that's what happens when you only have one example to go by ( as atmospheric scientists only have one earth ). If a simulation end result fits the observed world, it is easy to conclude that the parameters entered must also correspond with the real world. But that is a dangerous mistake to make.
New planetary systems have been discovered......and.....oops.....all of a sudden the MAJORITY of systems are wild places that don't fit the standard model at all ! Our system is the exception rather than the rule. And of course, it turns out that original simulations have been biased towards getting an answer that explained our type of system rather than systems in general. But we'd never have known that without the observation of other systems.
And so it is with atmospheric simulations. It is entirely possible that one could create an exact simulation of our atmosphere and its behaviour by inputting all the wrong parameters yet still getting an output that matched the real world.
There's even been a recent case of a splendid 'flythrough' simulation of galaxies and the effect of dark matter in the universe.....all very impressive as the simulation creates a universe that looks just like ours. Yet it's since been questioned as having parameters that have been tweaked that don't match more recent real world observations.
In fact, science is littered with such examples.
When scientists did the Viking lander on Mars, one of the tests was for microbial life. The test was done, and the results came back positive. It simply had not been considered when designing the experiment that something else totally unrelated might give the same results.
And that's the real issue here. People are doing simulations precisely because they don't know all the factors involved. If they knew those factors, they would not be doing the simulations because they'd already know the answers ! As is always the case, there are multiple input scenarious that can create any one output. A match ( as in the case of the solar system accretion model ) does not constitute 'undeniable' scientific evidence.
Your criticisms of the use of computer models seem to me valid ... up to an extent.
You seem to me to have given two examples of where a computer simluation has not proven to be effective.
However, such computer simluations go on all the time in almost all areas of physics. And 99.9% of the time, they are immensely successful.
I admit that the evidence is perhaps not completely 'undeniable'. Fair enough. But the evidence is so strong as to make it undeniable that the evidence for man made global warming is vastely superior to the evidence against.
In short, the sums of those arguing it is caused naturally do not add up. They cannot explain the shear extent of today's warming.
please excuse my ignorance, but what data do they put into these models, do they include historical facts and how far back do they go? if they are looking at the last 1000 years, then man has made an impact, but that is a miniscule amount of time compared with how long the earth has had an atmosthere that supports life.
I am not really qualified to speak on the exact data that is inputted into the models. You could ask Heritic; he seems far more knowledgeable on the particular details than me.
However, i do know enough about the scientific community to know that if there was something obviously wrong with their compter models they would have already been rejected. I have also listened for scientific criticism of those simulations and the only criticism I have so far heard was either a claim that it ignores natural factors, which I know to be false, or they rely on data that is proven to be fraudulent.
The reason they went back 1000 years is that was when accurate records began. Alas, the dinosours did not take scientific measurments, at least not ones that meet the accepted standards of most scientific journals .
Your point is very profound though. The lack of data is a major reason for why environmental physics is less accurate and has more uncertainties than almost any other scientific field. Nevertheless, these guys can still do alot with what they have.
Originally posted by Chi Squared: I hate it when people use terms like 'undeniable' over things that indeed CAN be denied.
Everything can be denied by someone. So perhaps the word "undeniable" is superfluous. Or perhaps denying some things is a mark of stupidity, ignorance, dishonesty or some combination of the three and these things are therefore rightly called undeniable.
As far as I can see, all the hockey stick says is that our understanding of a marvellously warm medieval warm period lasting hundreds of years is based on european anecdote, and wasn't an astonishing global warming. End of story.
We still have an unexplainable period of warming within a physical system we understand reasonably well.
If there were a large global medieval warming, and we went back in time with our current detectors, I'm pretty confident we would find the cause of it.
Even if the sun had warmed up X percent and brought about tropical conditions in Europe and New Zealand for 3 centuries, we know now that the sun has not warmed up sufficiently in the last 50 years to produce current warming.
I might be wrong, but my understanding was that the medievil warm period did happen over a sizable section of the globe (>15%). However, I also understood that scientists have been able to explain it, and the little ice age, using the natural factors. However, as you said, those same natural factors cannot explain today's warming.
So I differ from you in that I think the medieval warm period HAS been adequately explained.
I might be wrong, but my understanding was that the medievil warm period did happen over a sizable section of the globe (>15%). However, I also understood that scientists have been able to explain it, and the little ice age, using the natural factors. However, as you said, those same natural factors cannot explain today's warming.
quote:
I might be wrong, but my understanding was that the medievil warm period did happen over a sizable section of the globe (>15%). However, I also understood that scientists have been able to explain it, and the little ice age, using the natural factors. However, as you said, those same natural factors cannot explain today's warming.
So I differ from you in that I think the medieval warm period HAS been adequately explained.
Reconstructions have suggested average global temperatures were a bit warmer in 950-1300, a bit cooler later on, but the warm period was probably not as warm as it now. I've read a bit of the literature regarding reconstructions that cover regional areas, and the MWP seems to be a peg that some scientists hang any 50 year warm period that they find even if the 50 years previously or afterwards are colder than normal.
I'm pretty sure that there is no consensus over what caused these mild variations in climate, but feel free to point me to some references.
Everything can be denied by someone. So perhaps the word "undeniable" is superfluous. Or perhaps denying some things is a mark of stupidity, ignorance, dishonesty or some combination of the three and these things are therefore rightly called undeniable.
Or maybe I simply know what 'beyond all reasonable doubt' means.
Originally posted by Chi Squared: Or maybe I simply know what 'beyond all reasonable doubt' means.
I have no idea whether you know what it means or not and I don't much care. What I do know is that the similarities between the creationist evolution-deniers and the global warming-denier are striking. We see the same use of strawmen, pseudo-science, claims that the evidence can interpreted both ways and endlessly repeated untrue claims. But most strikingly, we see the "proof" of the deniers position being nothing more than picking holes in the details of the science.
Hockey stick undeniable? Well, apart from the fact that it has been shown to be a falsely-handled statistical process that tends to produce hockey stick shapes out of random data (McIntyre and Macintrick, Wegman et al, NAS panel report, the later two of which were presented to the US Senate), and that it relies on the inclusion of Bristlecone pine data from the western US which are not a proxy of temperature but of moisture and CO2 fertilisation.
The hockey stick graph also has another slightly naughty bit of presentation, in that it does not show where different proxies overlap, or the change from proxy to directly measured data. Further, apparently some of the proxy data used has been extended to recent times (rather than the cut-off at about 1980 used by Mann), and does not perform well at showing the recent warming trend.
There are a large number of papers and studies that show evidence of the MWP around much of the globe, and only this method of multi-proxy study that contradicts these (multiple papers have been produced by Mann and associates (see Wegman and his network analysis of associations within this area of proxy studies), but all rely on similar data sources, so inherently have similar deficiencies).
Originally posted by real scientist: ....However, such computer simluations go on all the time in almost all areas of physics. And 99.9% of the time, they are immensely successful.
That's rather a broad, unprovable statment. I certainly won't request a reference.
You seem to me to have given two examples of where a computer simluation has not proven to be effective.
However, such computer simluations go on all the time in almost all areas of physics. And 99.9% of the time, they are immensely successful.
They are generally successful in areas where most of the parameters are known, and what is required is a massive calculation that only a fast computer can do. For example, programs that search for genetic structures are generally using known input data and are being used because it would take several thousand years for a scientist to do the calcs. Similarly, there are simulations that create patterns of traffic flow....based entirely on known patterns of driver behaviour.
But it's an entirely different matter when the entire purpose of the simulation is that you DON'T know the total effect of all your parameters and are tweaking each one to try and see what combination matches the real world. There you have examples such as solar system formation models. The science is pretty well known ( as with AGW ), but the real problem is that there are actually multiple different parameter levels that can create the same end result. For solar system models you have to know not only material density and distribution but also the effect of the rapidly brightening sun on pushing lighter material outwards. Then there's the dragging of that material on planetary orbits, orbital dynamics, etc, etc. Every single area is individually a 'known' area of science with expected scientific behaviour. So for certain input you'd expect certain output. BUT, because there are so many factors you get a situation where, for example, tweaking factor B and factor G may in fact have the exact same effect as tweaking factor X. And so on. Thus you actually have not ONE but multiple possible paths that lead to the same ( or very similar ) end result.
And I cannot imagine it is any different with global warming. There is no one single climate model. There are clearly multiple different models. The very fact that we get forecasts ranging from 0.5 degrees to 6 degrees is an indication of just how varied the parameters are.
AGW advocates will argue that all these models say essentially the same thing. Well they will do, because CO2 is input as a greenhouse factor and clearly if you input it as such and run the model then you are going to get a warming effect ! But that is not the same thing as establishing that CO2 is THE factor responsible, only that you can create a model where it appears that way. What you don't know, precisely because this is a simulation entirely based on tweaking parameters, is the extent to which the CO2 factor might be negated by some feedback nechanism and other factors be the real cause......or a mixture of both, or whatever. All the simulation tells you is that given a precise set of assumptions you get a certain end result. What the model cannot tell you is whether your input assumptions are correct in the first place.
The following article says it better than I could. Keep in mind that it took at least twenty years after its discovery for doctors to accept the findings. Old dogmas die hard. Thus, the reason for the long delay in awarding the prize. I have used this example for years in making the point about "consensus" in various debates with colleagues and others. It was to my extreem delight that the researchers were finally awarded their just recognition. Sometimes--just sometimes, yesterday's consensus is today's folly.
SCIENTIFIC CONSENSUS AND THE NOBEL PRIZE
The Wall Street Journal, 4 October 2005
TIME was when our best medical minds thought peptic ulcers were a lifestyle disease, the result of too much stress, too much spicy food or some combination thereof. For treatment, doctorly prescriptions included time off work, chewing your food thoroughly, popping antacids and drinking quantities of milk. In severe cases, patients went under the knife to have their stomach linings removed.
So it is not altogether surprising that when Australian physician Barry Marshall suggested, at a Brussels conference in 1983, that peptic ulcers might have a bacterial cause, his findings were dismissed by colleagues as "the most preposterous thing ever heard", according to his entry in the Current Biography Yearbook. Far from being deterred, however, Marshall pursued his line of inquiry into a bacterium named Helicobacter pylori, which had been discovered by his Australian collaborator Robin Warren and which seemed to be closely associated with gastric inflammation. Marshall even went so far as to make himself a research guinea pig by drinking a microbial stew that caused him to become ill but that further confirmed the validity of their hypothesis.
Today, the milk-and-rest cure is a thing of the past, surgeries are rare and a disease that affects four million Americans annually can usually be treated successfully within a few weeks with an antibiotic cocktail. For their findings, Marshall and Warren shared this year's Nobel Prize in Medicine. It's an inspired choice and a useful reminder that just because there's a scientific consensus, that doesn't mean it's true.
Thus, the reason for the long delay in awarding the prize. I have used this example for years in making the point about "consensus" in various debates with colleagues and others
I've myself cited a number of examples where scientific 'concensus' has been wildly wrong. Plate techtonics was initially dismissed as a 'crazy' idea. The big bang was initially dismissed as a 'crazy' idea ( indeed Fred Hoyle coined the term big bang as a derisory term ). Even relativity was initially dismissed ( for some 15 years or so ) by scientists who were hung up with the 'ether' model of things ( despite Michelson and Morely having done an experiment that proved the ether did not exist ! ). The list is endless. Only last night I was watching the documentary on gamma ray bursts.....and yes you guessed it....the idea that they come from the far edge of the universe was dismissed as.......'crazy'.
I've myself cited a number of examples where scientific 'concensus' has been wildly wrong. Plate techtonics was initially dismissed as a 'crazy' idea. The big bang was initially dismissed as a 'crazy' idea ( indeed Fred Hoyle coined the term big bang as a derisory term ). Even relativity was initially dismissed ( for some 15 years or so ) by scientists who were hung up with the 'ether' model of things ( despite Michelson and Morely having done an experiment that proved the ether did not exist ! ). The list is endless. Only last night I was watching the documentary on gamma ray bursts.....and yes you guessed it....the idea that they come from the far edge of the universe was dismissed as.......'crazy'.
All the examples, yes every single one, are flawed. You have not given an example of where scientific consensus disagreed with a theory and then changed. Instead, you have given examples of where scientific consensus felt there was no evidence to support a theory. This is a fundamental distinction.
In Philipper's bacterial cause for peptic ulcers example, again, all he demonstrates is the scientific communities resistance to new ideas that had not yet been thought of or tested; not, the hasty acception of false theories.
The first, the one you are trying to imply, suggests that scientists sometimes make hasty claims only to take them back a few years later. The second suggests that scientists are very careful about what they accept and will only accept something when there is overwhelming evidence for it.
Man made global warming from CO2 is a perfect example of a theory that only became widely accepted when the evidence for it became overwhelming.
I challenge you to find one example where a theory overcome the natural resistance, became widely accepted by consensus in the scientific community, and then turned out to be wrong.
quote:
They are generally successful in areas where most of the parameters are known, and what is required is a massive calculation that only a fast computer can do. For example, programs that search for genetic structures are generally using known input data and are being used because it would take several thousand years for a scientist to do the calcs. Similarly, there are simulations that create patterns of traffic flow....based entirely on known patterns of driver behaviour.
But it's an entirely different matter when the entire purpose of the simulation is that you DON'T know the total effect of all your parameters and are tweakin
. 
