That was an observation not an attack. Anyone who can’t see that ‘experiment’ is utter nonsense is not qualified to express an opinion. Compared to that ‘experiment’ the simple unqualified statement about co2 is einsteinian.
All other things being equal (which is the big ‘all’) more co2 means increase in temp. But climate isn’t governed by one variable so such a linear model is not useful.
If pro-AGW sentiment is “religious,” could anti-AGW be considered equally “religious” for largely the same reasons (laypeople take the word of perceived authority, certain powerful people stand to gain wealth if their view prevails, etc.)? Why shouldn’t it apply both ways?
You can knock yourself out. I’ve clearly forgotten more about science than you know. And I’ll leave it to others with more patience than I to explain why a small micro-environment sealed in a glass dome isn’t even a vague approximate to the Earth for any basis let alone climate modelling.
I’ll stick my head out and guess one ice age back. It could very well even be beyond that, though.
We’re not talking about fluctuations of 0.2 degrees in the span of 10 years; those have happened before. What hasn’t happened before (recently, anyway) is a fluctuation of 0.8 degrees within the span of 125 years. This is kind of why attention was drawn to it in the first place, eh?
In reality, I just should have nipped your proposal of looking at the yearly average of fluctuation in the bud when I had the chance. When you do this, you lose track of the actual time span in which the change is occurring, which is a severe oversight in cases like this.
For example: imagine a 150 year window. Say between 0 and 75 (on the x-axis), the average temperature fluctuation jumps from 0.2 degrees to 1.5 degrees. Then, from 75 to 150, it dives back down to 0.2 degrees. If we look at the average, we end up saying, “Look, the average fluctuation is nothing new (0.2 degrees), so what’s the big deal?” The big deal isn’t visible through the average - it actually hides the problem.
LilShieste
The basic problems with this experiment are the following:
(1) While the absorptive properties of CO2 in the infrared are well-known, it does take a fair bit of calculation with radiative transfer codes to translate this into what the effect forcing in W/m2 is for the earth’s atmosphere. And, an important component of this is the fact that in the troposphere the temperature decreases with height. This is important because at the end of the day, the radiative forcing arises because the net effect of increasing CO2 is to raise the effective level from which the atmosphere re-emits energy back into space. Since it is cooling as you go up and since the power emitted by an object goes as the 4th power of the temperature, this results in less energy being emitted which puts the earth out of radiative balance (i.e., it then receives more energy from the sun than it re-emits). This causes the atmosphere to warm until it gets back into radiative balance. Clearly, this whole scenario would be hard to re-enact in a terrarium of any realistic size we could build. However, the calculations to determine this radiative forcing are so well-settled that even skeptics like Richard Lindzen agree with the accepted value of ~3.7 W/m2 for a doubling of CO2.
(2) Going from radiative forcing to the resulting temperature change requires modeling of the atmosphere & oceans & land & cryosphere, etc. since the various feedback effects discussed above come into play. These feedback effects are the source of the greatest uncertainty in how large a warming gets produced (i.e., what the climate sensitivity to increased CO2 is). There are really no shortcuts to actually seeing how the entire system responds, which is why looking at the response to the eruption of Mt. Pinatubo or looking at the transitions from ice age to interglacial periods are important things to test whether the models are realistic.
All of the experiments I discussed put the hypothesis at risk. E.g., if the response of the climate system to the Mt. Pinatubo eruption was much less pronounced than the climate models predict, that would be a problem for the AGW hypothesis (or, more precisely, the hypothesis that the warming due to greenhouse gases would be significant). Likewise, if Hansen’s 1988 modeling exercise had significantly overestimated the warming seen over the following 2 decades, that would have been a problem.
Climate models apparently have something on the order of 10 or 20 parameters for processes that they can’t resolve on the scale of the model and thus must be parametrized, I believe. However, most of them are constrained by the present climatology and they tend not to be parameters that allow significant flexibility in fitting to historical data on global temperature trends. Furthermore, the climateprediction.net experiment looked into varying many of these parameters over physically-plausible ranges and found that, while they could produce some very high values for climate sensitivity, they could not produce very low values…and most of the values produced were in the range of what is generally accepted to be the likely value.
I was assuming a bit more of an output. With that simple a result, I agree that many models would guess right, and the test for a good model would be a lot more stringent. You’d need a lot of results to drive the p value down to reasonable numbers. I’d want a lot more output in order to test the model in any reasonable way.
It’s all about the ability to make predictions - everyone who creates models knows this… It is trivial to draw a best fit line through any set of points, but that is useless. So, if the models got made with all the data, and not tested, I’d agree - but then all scientists doing models would be witlings. This I doubt.
