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How Well Do Our Climate Models Match Our Observations?
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?"
It's almost as if there aren't big walls in the sky that keep emissions from leaving the countries that produce them.
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." http://en.wikipedia.org/wiki/Roy_Spencer_(scientist)#Climate_change 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.
That is a perfect example on how to misalign graphs to make them match your agenda. He should be jailed for that.
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.
Love sees no species.
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!"
China are experts on big walls, though.
Well, no, it doesn't just need a 2C drop to get an ice age. It needs a continuous temperature shift of 2C or more in higher-latitude temperate regions without any significant actions to remove the snow. After a couple years of that remaining true, the increased snow cover will become self-sustaining until acted on by a sufficient contrary change of some kind. Then you get an ice age.
Dramatic climate changes don't work off the global average temperature, they work off regional interactions across large enough scales to become resistant to the minor fluctuations.
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.
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.
Or the fact that we are still coming off of an Ice Age that lasted for more than 100,000 years, and ended less than 10,000 years ago (Or the little Ice Age that ended in 1850). Several models predict that the average temperature at the END of the last Ice Age was 15-20C lower than today.
So over 10k years temperature raised 20C, that is (20 / 10000) * 10 = 0.02C per decade, very far from 0.7 / 3 = 0.23 per decade that we see now.
I don't have sources from your numbers, and it's probably safe to assume that the rate of temperature change isn't constant either... So maybe we shouldn't try to model this at all, my calculations above are certainly as ignorant and non-sense as your postulation of numbers...
Is global warming happening? Yes. Is the human race a contributing factor? Probably to some degree. Is the human race the only cause? No.
True, there are many factors that affect the environment, but non other does it with the same speed as humans.
Global warning is primarily man-made, it's a real problem, that's the scientific consensus. And I'm fairly sure that most people on slashdot as just as qualified to discuss the scientific consensus around global warming, as soccer moms are qualified to discuss the merits and "dangers" of vaccinations.