Reply #44: I agree

[Nederland]

There exists no credible reason for the warming that has occurred other than AGW. What I do not believe is that the current rate will increase to 3.0C per century. The supposition that the rate will increase to 3.0 is based upon speculation regarding CO2 feedbacks that are at this point in time unproven (you can't prove them in a lab, all you can do is observe the way the planet responds to the current conditions and wait). I also think that you misunderstood my comments with regard to 1.6 C. I was referring to the observed record. That is why I said that unless you engage in blatant cherry picking, no trend line exists that exceeds 1.6 C. This is not a matter of opinion, it is a historical fact. Take a look at the temperature record yourself. Depending on what source you use, the 5 year trend is negative, the ten year trend is around 1.0, the twenty degree trend is around 1.6, the thirty year trend is around 1.5, the fifty year trend is around 1.3, the seventy year trend is around 0.9 and the hundred year trend is around 0.7. So, as I said, unless you blatantly cherry pick a period like 1988 to 1998, you can't find a period that exceeds 1.6 C.

An important point to understand regarding climate is that CO2 is not the only actor. You quote the party line when you say "there exists no credible reason for the cause other than AGW", and as I said, it is true. However, it is also true that you cannot explain the twentieth century temperature record changes with CO2 alone. Plot a graph of 20th century temperatures superimposed on a graph of 20th century CO2 levels. You'll see periods of temperature changes that cannot be explained by changes in CO2 levels, so obviously there are other forcings at work. Even if you include all the anthropogenic forcings, you still can't explain the full 20th century temperature record. Obviously therefore, the trends that we have observed over the last 100 years are a combination of natural and man-made forcings. It is the exact quantification of all the forcings that are at work that is very much unknown at this point. Hell, the different models all use different formulas, so to claim that climate sensitivity is "settled science" is ridiculous on its face.

Look at the graph I posted above. None of the individual models come even close to modeling reality. None. Sure, when you smooth out the graph by averaging all the models together you get something that looks vaguely like the historical record, but that is meaningless. The fact is that all the individual models are wrong, and if you think that you can possibly get a correct answer by averaging a bunch of wrong answers together you have a serious cognitive deficiency.

Finally, I have to make a point regarding a most curious statement you made. You said "the newest models will have pretty good cloud forcings". This is not a scientific statement, it is a statement of faith. It is a statement of faith because what makes a "good" model is the ability to predict future conditions. Since future conditions have by definition not happened yet, you cannot possibly have any evidence that the cloud forcings in the newest models are "pretty good". Let the models predict what the next ten years will look like, then wait ten years and compare the predictions to the observed record. Then and only then will you be able to say whether or not the new cloud forcings are "pretty good". Right now you simply cannot know.