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Earth Stats Science

How Well Do Our Climate Models Match Our Observations? 560

bunratty writes "According to recent articles by Roy Spencer and John Christy, our climate models have done a poor job of predicting warming due to humans burning fossil fuels. They claim that we've observed only a fraction of the warming they predict. But when I look at the source they claim to use, the State of the Climate in 2012, I see that it shows a warming of 0.7 degrees Celsius worldwide since 1980, close to the 0.8 degrees Celsius warming predicted by the climate models. Take a look at the data for yourself. How well do our predictions match our observations?"
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How Well Do Our Climate Models Match Our Observations?

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  • Predictive Power (Score:5, Insightful)

    by simonbp ( 412489 ) on Thursday February 20, 2014 @12:36PM (#46295415) Homepage

    That's because you are looking at climate models calibrated against that data that you are comparing to. Circular logic.

    If you look at the predictions from past IPCC reports, very few of their predicted temperature profiles match the later observed conditions. That is a failure of the models' predictive power. That doesn't mean there isn't warming, just that the Earth's climate is a more complex system than can be accurately simulated with modern computing hardware.

  • Re:BS (Score:0, Insightful)

    by Anonymous Coward on Thursday February 20, 2014 @12:46PM (#46295531)

    Oh yeah, right. Any observation that contradicts the religious creed of AGW doesn't count. A warm spell somewhere is evidence for AGW, but a cold spell across a region should be ignored.

  • by Anonymous Coward on Thursday February 20, 2014 @12:47PM (#46295543)

    Spencer has contributed specific work in peer reviewed journals that is part of the scientific discussion, but his overall opinion on climate change is motivated more by his own religion than anything else. He's both sympathetic to intelligent design and signed a statement which said among other things ""Earth and its ecosystems – created by God's intelligent design and infinite power and sustained by His faithful providence – are robust, resilient, self-regulating, and self-correcting." [] Essentially he believes that climate change isn't happening because his religion won't let him. Note how that statement wasn't even just about climate, but about ecosystems as a whole. Christy doesn't seem to have that same sort of underlying motivation and might make more sense to pay attention to, but in this context, the vast majority of experts disagree with both of them, and when dealing with complicated scientific issues, using expert consensus is a useful heuristic, that's before we get to the serious issue that not only is the expert consensus clear, it is a consensus about some very bad results, not just a consensus about an issue which doesn't have substantial impact.

    As opposed to climate change being a religion unto itself

    Guess you must have missed this from TFA:

    Messrs. McNider and Christy are professors of atmospheric science at the University of Alabama in Huntsville and fellows of the American Meteorological Society. Mr. Christy was a member of the Intergovernmental Panel on Climate Change that shared the 2007 Nobel Peace Prize with former Vice President Al Gore.

    Got anything to say about Mr. Christy?


    Take your ad hominem tripe elsewhere.

  • The Worst Offender (Score:5, Insightful)

    by KermodeBear ( 738243 ) on Thursday February 20, 2014 @12:50PM (#46295591) Homepage

    I can't speak to the accuracy of historic weather data or modern weather models, but I can say this:

    Global Warming / Climate Change (pick one, please) alarmists do themselves an incredible amount of damage when they do the following:

    1. Grossly exaggerate predictions and base everything on the worst case they can find.
    2. Manipulate charts to make changes look far more significant than they really are.
    3. Instantly ridicule anyone who disagrees with them on anything, even if that disagreement is valid.

    Let's say for the sake of argument that all of the predictions from these weather models are 100% accurate, all of the research and data is correct, and that the climate is indeed warming because of CO2 emissions, and that the climate will warm 5 Celsius degrees in the next 200 years. Let's pretend that the science is completely perfect.

    Even if all of that is true, you will find a lot of people who won't even bother listening because they remember crazy predictions like "New York city will be underwater in 20 years! []" and "We're all going to be cannibals! Cannibals, I say!" []

    Do you see why so many people don't listen to those who are trying to push human-caused climate change?

    Politics needs to be taken out of the equation. Completely. Everything needs to be 100% transparent. The science needs to be broken down in ways the average person can understand. Even if that happens, it will be decades before the damage the global warming alarmists have caused can be reversed.

  • by ColdWetDog ( 752185 ) on Thursday February 20, 2014 @12:51PM (#46295603) Homepage

    The cherry picking and slanted explanation of the data most assuredly does.

  • by MozeeToby ( 1163751 ) on Thursday February 20, 2014 @12:52PM (#46295613)

    Small fluctuations in local weather are much, much, much, much more chaotic than large fluctuations in global climate. This is hardly unique to atmospheric sciences.

    Lets us an IT analogy, lets say you manage a large data center and your head of IT comes up and says something like this:
    "Over the next 5 years, 15% of the hard drives in this data center will fail. We need to take these basic precautions."

    Your response would be like:
    "Why on earth should I trust your estimate for 5 years from today when you can't tell me exactly which servers will fail within the next 6 months!?"

    And then you'd get angry at him 5 years down the road when only 14% of the drives failed and be all like:
    "See! I told you there was nothing to worry about!"

  • by Grantbridge ( 1377621 ) on Thursday February 20, 2014 @12:58PM (#46295681)
    How long do you think it'll take for you to bleed to death if I shoot you with a pistol? Its not an easy problem to predict. You don't know precisely where you will be shot, if the bullet will go straight through or lodge in bone, or ricochet. You don't know how long your blood will take to clot. You can be pretty sure that, left unattended, you will die from being shot. But predicting exactly how long you will have is rather hard. CO2 levels cause global warming by basic physics, just as a greenhouse is warmer inside than outside. You trap the heat in, but let the visible light through. What the exact consequences of a certain CO2 level are is hard to say preciously, but if CO2 levels keep going up and up and up you can be sure that the polar ice caps are going to melt and sealevels are going to rise dramatically. Precisely when this will happen is as hard to predict as how long it'll take you to bleed out from a gunshot wound, but you wouldn't argue that because its hard to determine how long you have, it's not worth trying to avoid getting shot!
  • Re:BS (Score:5, Insightful)

    by beatle42 ( 643102 ) on Thursday February 20, 2014 @12:59PM (#46295695)

    I don't think it should be surprising if changes in climate affect the behavior of people in areas. If food becomes more plentiful I bet crime goes down. If food and water become more scarce I bet it goes up. If the weather patterns are changing surely some areas are going to get drier and some are going to get wetter. Also, as events become more extreme all the extreme weather events you sited are likely to happen more often too, don't you think? So you're right, global warming almost certainly is doing all those things.

    I don't see why it's controversial to think that. Even if you don't think people have anything to do with changing climate all those effects are obvious outcomes of it changing, and I don't think many people actually doubt that it is changing.

  • by cirby ( 2599 ) on Thursday February 20, 2014 @01:01PM (#46295719)

    A big reason you won't see any critiques of that sort is that the influential folks in the AGW alarmist camp made a big effort to block any critical papers from even being considered. Threats to blacklist journals for publishing "anti-AGW" papers, for example, or to take behind-the-scenes action against anyone who tried to submit such papers.

    This all came out in the Climategate emails. But you never heard about those, did you?

    They also admit in those emails that most of the actual criticisms of "mainstream" AGW were valid, and discussed ways to cover it up.

    "Hide the decline" ring a bell?

    Or "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't. The CERES data published in the August BAMS 09 supplement on ... shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate."

  • by 93 Escort Wagon ( 326346 ) on Thursday February 20, 2014 @01:05PM (#46295741)

    Look back before that, the period from 1950-1974 (approximately). How well do the models match there?

    Cherry picking is bad science. You have to look at the whole record from the start of the Industrial Age... and the models haven't been particularly good.

    That's not an anti anthropogenic global warming statement, by the way. It's a "science is hard and you can't understand a subject after ten minutes of reading" statement.

  • by Anubis IV ( 1279820 ) on Thursday February 20, 2014 @01:06PM (#46295753)

    When it comes to modeling, "predicting" old data is actually an invaluable technique for developing useful models. For instance, if you're working with machine learning algorithms, it's typical to segregate your data into a training set and a test set (sometimes an additional validation set as well). The training set is used to teach the machine learning algorithms, thus establishing a model. You then take that model and run it over the test set to see how well it matches.

    Put differently, rather than creating a model from all of the old data (which, as you said, is trivial and not really that impressive), you put yourself in the shoes of a 1970s scientist and try to use the data from only up to that point to create a model that will work for the next 40 years. You then get to fast forward 40 years and see how you did. If you didn't get it right, you go back and try again.

  • by EvilSS ( 557649 ) on Thursday February 20, 2014 @01:08PM (#46295767)

    0.8 degrees Celsius is in fact about 1 degree Celsius.

    Well, +/- 20%

  • by Anonymous Coward on Thursday February 20, 2014 @01:10PM (#46295789)

    Check your math--1990-2025 is 35 years, or 3.5 decades. At 0.16 degree C per decade, that's 0.56, not 0.8. And it's a lot harder to argue that 0.56 is "about 1"; most people would say that it's "about one half".

  • by AmiMoJo ( 196126 ) * <> on Thursday February 20, 2014 @01:46PM (#46296171) Homepage Journal

    Actually predictions of the amount of warming have been pretty accurate, what was unexpected was that the atmosphere stopped warming so much and instead a lot of the energy went into the oceans. Sceptics make a lot of the recent "pause" in warming, but actually there is no pause when you remember to consider the oceans as well as the atmosphere.

  • by Anonymous Coward on Thursday February 20, 2014 @04:48PM (#46298437)

    Says the person who links to the EPA.

    Seriously, you couldn't find a less biased source? They're the kings of "because we said so". Are they interested in climate change? You bet. They're bullies who derive their power from the idea that man is mucking up nature.

    The debate is already way too cluttered with political rhetoric without people linking to the !@#$ EPA.

  • by SuperKendall ( 25149 ) on Thursday February 20, 2014 @05:37PM (#46299017)

    "..models are fundamentally flawed .."
    They are not. Not by any stretch.

    That are off by nearly 50% over just 30 years (see earlier post about being 56% lower than predicted by 2025).

    If that's not a sign of a fundamental flaw, what is? How can you say what climate will be like in 100 years when your model has a +/- 50% error rate?

  • by BlueStrat ( 756137 ) on Thursday February 20, 2014 @06:24PM (#46299523)

    Oh no. The government of the United States, how untrustworthy compared to an anonymous stranger on the internet.

    With the US government's track record for truthfulness and "transparency", particularly over the last 20 years, I'd be far more inclined to trust Joe Isuzu over the US the government. []


  • by hsthompson69 ( 1674722 ) on Thursday February 20, 2014 @08:04PM (#46300371)

    If you want to assert the anthropogenic greenhouse effect is both real, and dangerous, the burden of proof is on the affirmative to come up with a necessary and sufficient falsifiable hypothesis statement which rules out natural climate change as the reason for observed temperatures.

    0.7C doesn't validate a non-falsifiable model, even if that's close to what the model predicted. Even astrologists make predictions, but astrology isn't science.

  • by Eunuchswear ( 210685 ) on Friday February 21, 2014 @08:49AM (#46303087) Journal

    Venus isn't hot because of the greenhouse effect, it's hot because of the enormous pressures caused by an incredibly dense atmosphere.


No problem is so large it can't be fit in somewhere.