An issue has been made about facts and data in this thread. However, GW is a prediction of future calamity and there are no facts or data from the future, unless somebody has a flux capacitor handy. Thus, it all boils down to this; do you trust the climate model makers? And if so, why?
Because they are the single greatest source of expertise within that area. Let me switch that question around - who would you suggest we trust?
These quotes are from the Nobel prize winning IPCC report:
"One source of confidence (in the models) comes from the fact that model fundamentals are based on established physical laws, such as the conservation of mass, energy and momentum..." The report assures us that "powerful computers" were used (and these quotes are from the scientific report, not the dumbed down version for policy makers).
OK, swell. How sophomoric is it to assure us that the models use accepted physics and big computers?
Because it demonstrates that we are studying reality, and not ideas cooked up in our heads. If those models were based on hypothetical ideas they would not be very good. Because they are based solely on known, proven physical laws we know that they are the best possible representation of reality we can derive
without having to resort to assumptions, "fudge" factors and guesses.
The "big computers" is simply a caveat added to most modern studies, as the amount of computing power required for these models is massive. So its pretty standard to state exactly how much computing power you used in order to show that your results are actually possible, given the technology at hand.
Can you imagine a molecular biology paper assuring us that its conclusions were valid because the authors accepted the laws of biology and used really, really good lab equipment?
We do it all the time. In my work I use technology only available in a few labs, and is quite rare/expensive. However, this technology allows me to preform experiments not possible with common equipment (i.e. tracking single molecules within living cells). As such it is very important to clearly state what I am using, as it proves that my equipment is capable of doing the things I claim. Likewise, I also have to describe the physics and mathematics used by the equipment to show that I'm staying within the bounds of proven science, and I'll reference proven biology when making conclusions, to show that I'm not making unsupportable jumps in logic.
Its all part of good scientific methodology and reporting.
"Some climate models, or closely related variants, have also been tested by using them to predict weather and make seasonal forecasts."
I'm sorry, I thought weather predicting and climate forecasting were separate things. I was chastised for this by a medical researcher/climatologist in a prior post. Again, the monumental success of predicting short term hurricane frequency really inspires my confidence.
They are. However, climate determines general weather patterns - i.e. overall rainfall patterns (amount of rain at different times of year), seasonal cloud cover, temperature trends, and so forth. As such a good climatological model should accurately predict changes to these general weather patterns. It won't predict the weather on, say, June 23rd, 2009, but it will be able to tell you what the average temps, precipitation, cloud cover, etc are for the month of June in 2009 for a particular region.
And moderns models do a very good job of this. They do not however predict specific weather events - like hurricanes - for the very simple reason that the formation of specific weather events relies on so many variables that modern computers cannot model them accurately.
Finally, my own observation: the different models vary from one another by up to 100%.
Really? Perhaps you could provide a link demonstrating such. As the IPCC has noted, while the models do come up with differences in the magnitude of change, they all agree on one thing - a net warming of the earth.
In oher words, there is wide discrepancy among the predictions of different simulations. Thus, most of them HAVE to be wrong (since they disagree)...why not ALL of them?
While they do not agree on the exact amount of warming which will occur, they all see warming. At that level, they all agree. By your logic they must all be right...
My position is that these models of our future doom may be right, but they are probably wrong (as such computer simulations are). I don't understand them, but then neither does anyone else in this thread.
That is a huge assumption on your part. The mathematical principals used for climatological models are pervasive throughout science, they physics they rely on are exactly the same as the physics regulating everything else, it is only the application which is unique. I frequently sit down and read their papers, and understand nearly everything they write.
But the track record of such models in other realms (stock predicting, a less complex task) is quite miserable.
You cannot even compare the two. Climatology is simply the study of physics. Stocks are not, and rather are a study of human behavior more then anything else.
The position of some, however, even though they have no personal knowledge of these models,
Another huge assumption on your part. If memory serves, one poster here is involved directly in this work. In my own case I have worked with a simple climatological model during my undergraduate years, as part of a series of courses I took on computer modeling in science (my minor, btw). And while the models used today are far more complex then the ones I played with all those years ago, the underlying methadology, mathmatics, and routines remain the same.
is that they ARE right without question,
Hardly. But when thousands of climatologists all stand up together and say "the world is warming, and this is what's going to happen as a consequence", then I tend to believe them. When an economist says "those climatologists are full of crap", I tend to doubt him.
You, for some reason, appear to think otherwise...
so right that we have to drastically alter our lifestyles to suit their predictions.
As I pointed out in a previous post, this is complete and utter BS. I've personally reduced my CO2 output by over 1/2, with no significant consequences on my lifestyle. The only difference is that I have more free time (due to shorter commutes) and more money in my pockets (due to decrease costs of car ownership and utility usage).
These believers trust these models, even though the IPCC report itself admits uncertainties in them.
I think you are misunderstanding what they mean by "uncertainties". All of the modern models agree that the world will warm. Actual measurements of the earth confirm this is occurring. The "uncertainties" you think so readily undermine these models are mostly uncertainties on the degree of warming which will occur.
Or, in other words, the argument isn't "if" we're going to warm, but rather by how much. Not exactly strong grounds to base a plan of inaction on...
My question is: WHY? If you don't know these models personally, why oh why do you have such religious zeal in trusting them, even when the modelers themselves admit flaws?
1) Because there is a strong scientific consensus that the net trend indicated by those models (i.e. warming) is correct.
2) Because I understand how those models work, and know the underlying science is based on a strong scientific foundation.
3) Because I understand exactly where the deficiencies in the models are, and the nature of the resulting uncertainties is of no mystery to me.
4) And finally, because the flaws which we know exist do not invalidate the results. So while we cannot use the models to say exactly how much the world will warm, or exactly how profound changes in weather will be, we can say that the world will warm, and that detrimental changes in weather patterns will occur.
Is that because climate modelers are, as a class, beyond reproach?
No, it because they've got ~40 years of experience under their belt, have validated their models, and rely on proven scientific principals to generate their models. I would trust that 1,000,000x more then your approach - that being ignoring potentially dangerous consequences on the basis that the models cannot agree on just how bad it'll be.
Or is it because they say something that fits nicely with what certain people WANT to believe: America is bad, rich consumers are bad, oil companies are bad, and so on?
I don't want to believe any of those things. But your above claim is a classic strawman argument - you cannot deal with the data, so you try and distract up by putting up a false and inflammatory argument.
OH, and in response to my challenge that SB members who believe in GW give up recreational diving that involves dive boats or jet travel (why should people give up their SUVs if others can't give up dive boats) as a show of their REAL concern for the planet?
Why give it up when I can do things which have a far greater impact - like moving to a more fuel efficient car, no longer driving to work, and have further reduced my consumption of gas and electricity? I consider my odd splurge (i.e. flight) to be a small reward...
Bryan