Because it's the human version of putting rats in mazes and the sad thing is how many of us run the wrong way down the maze and grab the poisonous bit of cheese.
This statement itself should tell you :
"An indication of residence time can be seen from experiments using the Met Office Hadley Centre's Earth system model ..."
I watch the AGW/ACC crowd here try and defend the statement, but the reality of the statement isn't even close to being a factual representation. Read it slowly and understand the meaning of every generalized word (i.e. "indication", "can be", "experiments", and "model"). They totally mean nothing because they dilute the statement with too many generalities. That's how science tries to make themselves look important.
It's science saying something without saying a thing that is important!
Ottawa Mike - You said it was a partial answer. I laugh at you for even calling it that.
That's like saying "the Planet is warming, therefore, humans are responsible because they emit too much CO2 needlessly" when 'practical physics' says something totally different.
You have hit on a symptom of part of the current problem. Many scientists these days are of the computer game generation. You can play out "real life" scenarios and the computer will try and outwit you by using artificial intelligence.
Truly great experimental physics has not happened as far as I can tell in the climate change arena. People who call themselves scientists rely on the computer in preference to using data from the real world.
Some of the assorted 97% surveys were not surveys carried out by asking people questions. They were performed by sitting in front of a computer and categorising some data from Google Scholar or equivalent. Much of clmate science seems to be similar. Someone goes into the field and collects ice core or tree samples etc and then someone else will play with the figures until they have proved disaster and then publish.
Climate scientists need to realise the circularity of their arguments. They create a model. Refine it until the results look reasonable then claim that is what is happening. To prove their hypothesis they check it against the model.
Great physics is still being done. Think of the Higgs boson, for instance. In the past we had the Michelson-Moreley experiment that cast doubt on the ether and Eddington's photographs substantiating Relativity.
Unfortunately, this kind of person does not seem to be in climate science.
So you figure all those gedankenexperiments from Galileo onward, as well as all of the simulation experiments such as computational windtunnels are invalid?
You also figure that a Monte Carlo analysis, which specifically depends on the fact that the results don't always come out the same isn't an experiment?
How do you classify your attempts to modify the perception of science by changing the semantics?
>>Now apply that to a climate model. You can have the same model using the same assumptions and same inputs and it NEVER produces the same output. So again, how can using climate models be called "experiments"?
The models are stochastic and not deterministic. Surely, those concepts were addressed at some point in you engineering education. For crying out loud, there is an entire field of study dedicated the study of Stochastic Processes in Engineering Systems. The Bernoulli Society for Mathematical Statistics and Probability publishes a journal (“Stochastic Processes and Their Applications”) dedicated to the subject and the 36th Conference on “Stochastic Processes and Their Applications” is being held in Boulder this week.
http://www.sciencedirect.com/science/jou...
http://math.colorado.edu/spa2013/
Well you put different data into the model run it and see what results, it can be interesting and give insights into how climate works, however it is only a model not real life, so it depends on how accurate the model is, they are useful for understanding how climate might work, but only as a rough guide, if your model doesn't align with real life conditions, your model is wrong.
It’s referred to as an experiment because that’s what it is. An experiment by definition is “an orderly procedure carried out with the goal of verifying, refuting, or establishing the validity of a hypothesis”.
Because the climate is subject to chaos it’s never going to be possible to run the same experiment twice and get identical results, to do that would require the use of fixed values, which don’t exist in the real world.
To give you an overly simplified example, if you were to release a molecule of CO2 into the atmosphere now, it might remain there for five minutes, five years, five thousand years. It would be possible to assign an average lifespan to the molecule but what would happen if at some point during it’s lifespan you released an H2O molecule, this could interact with the CO2 causing it to become more effective as a greenhouse gas but also reducing it’s lifespan. Unless you can identify when CO2 will be released, when H2O will enter the atmosphere, when they’re going to interact and how they’re going to interact then you can’t predict exactly what the outcome is going to be.
It’s this phenomenal number of possibilities that means you’ll never get the same outcome twice.
If you think about it, six variables with ten possible values produces a million different permutations. Climate models have hundreds of variables, many with an almost infinite number of possible values. Even if you only had a hundred variables with a billion possible values then the number of outcomes will exceed the number of atoms in the universe a sextillion times over.
Because of this, a climate model will be run thousands or millions of times over, this then produces an average result, but you’ll never get the same result twice.
Because the question asked was specifically about the model.
Bernard Donoughue: What is the mean residential time of anthropogenically emitted carbon dioxide in the simulated atmospheres of the general circulation models that are run by the Met Office?
Sandip Verma: An indication of residence time can be seen from experiments using the Met Office Hadley Centre's Earth system model.
You seem to be bothered by a specific answers to a specific questions.
When all you have is models to push your cause, you want to exaggerate their importance so you change the name to experiment so that gullible people believe the models are more important evidence than they actually are. If they were honest and said models showed this or showed that, even gullible alarmists might get suspicious.
It appears that Baccheus believes that simply rewording the question provides the answer. Somehow I think if the model was something that wasn't favorable to AGW, he would agree that it would be ridiculous to call a model an experiment.
Its a imaginary proxy Earth ,except it does not include everything in the Earth .
Some Congressperson base their ideas on these imaginary Earths for taxes .
They think what it produces will happen .
Question about model output:
"Energy: Carbon Dioxide Emissions
Questions Asked by Lord Donoughue
To ask Her Majesty’s Government what is the mean residential time of anthropogenically emitted carbon dioxide in the simulated atmospheres of the general circulation models that are run by the Met Office.[HL1484]"
Part of the answer:
"An indication of residence time can be seen from experiments using the Met Office Hadley Centre's Earth system model ..."
http://www.publications.parliament.uk/pa/ld201314/ldhansrd/text/130718w0001.htm
So my question is, how can a climate model produce experimental data? How can you conduct experiments using a model?
I believe that the word "experiment" is used for computer simulations of any system. Of course, the real experiment is the one in which we are pumping carbon dioxide into the atmosphere for real.
Jim Z
Thanks for explaining why "skeptics" like to talk about computer models, rather than the basic physics like realists do.
