Ask an alarmist why we need to reduce CO2 emissions. Any answer he gives will have some sort of future prediction (or projection if you prefer). And then they turn around and say climate science doesn't do predictions or projections. That there is a failure of logic.
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Some around here might need to be refreshed as to exactly how the scientific method works:
1. Observe some aspect of nature.
2. Invent a tentative description, called a hypothesis, that is consistent with what you have observed.
3. Use the hypothesis to make predictions.
4. Test those predictions by experiments or further observations and modify the hypothesis in the light of your results.
5. Repeat steps 3 and 4 until there are no discrepancies between theory and experiment and/or observation.
If you don't follow those steps, then you're not doing science. I have to laugh at Hey Dook's question after this one where he compares climate science to earthquake detection. Because actually it's a very good comparison. Scientists have been trying for years to formulate an earthquake hypothesis which could be used to at least give some general predictions for future earthquakes. This would obviously benefit man greatly. However, there are currently none that are useful. And make no mistake, the use of such a hypothesis would come from the ability to make useful predictions. Doesn't that sound like climate science?
And you don't have to be a climate scientist to be able to criticize climate science with regard to application of the scientific method. If you're wondering why so many prominent physicists, including Nobel Laureates, have a problem with much of climate science, the above is the reason why.
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"In science, a prediction is a rigorous, often quantitative, statement, forecasting what will happen under specific conditions; for example, if an apple falls from a tree it will be attracted towards the center of the earth by gravity with a specified and constant acceleration." http://en.wikipedia.org/wiki/Prediction#...
This is exactly what climate models do. And they have a whole cart load of specific conditions for individual scenarios which change for each scenario (e.g. range of IPCC emission scenarios). In the time that has passed when these climate model predictions were made, we know the exact emission scenario we have followed and we have the global surface temperature observations so we can evaluate the models with the specific emissions scenario that has occurred.
I get the feeling that the resistance to we are getting here which includes questioning the length of the time period and now seems to include claiming no predictions were made in the first place has to do with the divergence between observation and prediction. But that's just my speculation from having been an observer of all this for the past few years.
And there's nothing wrong with claiming natural variability or oceans absorbing heat or human aerosols being the possible reasons for the divergence. Great, then go ahead and modify your hypothesis and make some new predictions. That's how science works (see Step 4 of the Scientific Method).
Oh wait, I thought the science was settled?
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Edit: This is a good read on the subject: http://www.academia.edu/1812111/Predicti...
Well, for one thing, they don't care when a particular ENSO event will be 50 or 100 years from now. Then if you look at a running mean of global temperature and average over a long enough time period, it will not affect the global mean significantly. This is part of the general confusion between forecasting weather and seeing how climate might change. A weather forecast would be a complete bust if I said it would rain today and it rained tomorrow instead, but that doesn't matter at all in a climate model, the same thing applies to ENSO.
It would be a problem if the model gets the frequency of ENSO events wrong to a large degree, or if AGW changes the frequency, and that is something that is carefully studied in the model output.
By the way, it is something of a myth that ENSO is not understood--it is a coupled ocean-atmosphere phenomenon associated with the generation of westward propagating Rossby waves and eastward propagating Kelvin waves, which cause the thermocline to shoal or deepen. The basics have been known for decades.
EDIT for Mike: Don't read things into my statements that I didn't say--modeling ENSO is difficult, that doesn't mean that we don't have a good handle on what's going on. There are many reasons why something can be understandable but difficult to model.
By the way, I won't disagree that this other scientist you heard is "of more global renown," but who is it? Why say that about somebody and not tell us their name?
Strange that pegminer says ENSO is well understood. I have heard another climate scientist, one of more global renown than pegminer for sure, though perhaps not technically a climate scientist, say that modeling ENSO is one of the biggest challenges remaining.
This same scientist was asked about his presentation which discussed LaNina like conditions in the tropics in response to warming in medieval times, 'doesn't that mean that climate models vastly overstate warming.' After joking that the questioner didn't look like Richard Lindzen, he said,"I agree with that. I have a reputation out there that I am some sort of climate alarmist, but I think there is a missing negative feedback."
Climate scientists do not, to the best of my knowledge, *predict* the future - be a nice trick if they could. Instead, they use, among other things, computer models to *project* possible future outcomes based on how an ensemble of models handles changes to "current" model conditions. It's important to understand the difference if you wish to understand a significant area of climate science. The extremely detailed mathematical theories of climate change that were incorporated into computer models years ago actually have projected the general "future" warming that we are now experiencing. Read the current IPCC report - it's all in there.
Clearly the "predictions" are general statistical projections of outcomes, much like insurance companies "predictions", which are not predictions of exactly who will die when, nor predictions of how many in a group die at any given time, but best estimates based on a mathematical theory which ties observations together. In a way, what you seem to be complaining about is the equivalent of insurance companies in 1920 not predicting World War II because their future projections did not show a mortality spike of the right proportions from 1938 or '39 to '45.
Its called Hubris.
People have a natural tendancy to want to believe they and/or understand more than they really do. Look at teenagers for raw examples of this. After a few days of driving, almost all tennagers are expert drivers, in their own minds anyway...
It is hard for many people to accept those things they can not change. It is also very hard for people to accept just how many things in their lives are byond their control no matter how much they wish it to be otherwise. I beloieve that for many, the current state climate science will become a study of this phenomenon in the futre. Fifty years from now, if this is remembered, it will be remembers jokingly as how could our grandparents and great or great great grandparents have beleived this stuff?
Lemme see if I can make an analogy for you.
Keeping in mind that the only perfect analogy for a thing is the thing itself...
I'm going shopping with my (hypothetical) 2-year-old. I'm trying to figure out how long the trip is likely to take.
I don't know if my kid's going to have a tantrum, which makes my shopping trips longer. And I don't know how long the checkout lines are going to be.
But does that mean I have no idea if my shopping trip is going to take 20 minutes or 5 hours? No.
I know my kid well enough to know that he has about an X% chance of throwing a tantrum on any given shopping trip. And I know certain factors (how tired he is, whether we pass the candy aisle without buying anything) that will affect his tantrum frequency.
And I have a good idea of how long the checkout lines tend to be at this store.
So, if I know what I want to buy in advance, I can make a pretty reasonable guess about how long my shopping trip will take, with a little "slop" for the probable tantrum frequency and variations in the average checkout line length.
You don't need perfect knowledge to make a prediction, you just need good enough knowledge to be able to give a range to the details you don't fully understand yet.
I am not sure the term for the condition but for warmons the greater the uncertainty the more concern.
ENSO and ocean cycles, how can they run computer models to predict climate.
