As you can most likely tell, I am not a scientist just a concerned citizen.

You must be in the UK, where indeed many claim it has been a warmer than normal fall (although, it would be interesting to look back at this Fall once we’ve passed the Solstice, given the turn to cold and rainy (soon to been snowy in Northern Scotland?) weather, over the past week.

Meanwhile, North America has already had Fall and is now in Winter.

As the Sun ages, it gets hotter. As it ages it consumes more of the hydrogen at its core and as such contracts and consumes a larger proportion of its helium. However over geologic time scales the temperature of the earth has been stable in the face of this changing solar input. The solution to this quandary is to propose some sort of negative feedback mechanism in the atmosphere, ocean etc. that would tend to act counter to the increasing solar input. Note that this process has been occurring for billions of years so the stability of the atmosphere in the face of forcing must be very strong. So the naive more CO2 means higher temperature must be compared with an Earth history in which the CO2 concentration has varied a great deal (sometimes much higher than now) and the solar irradiance has been constantly increasing.

Maybe it should be “relatively stable over a range of 10 degrees or so”.

Seems AGW doesn’t recognize natural variations of that much though, although geology does.

Also, are you willing to stake your credibility on that pasaage you quoted in #51 being correct? OTOH, I suppose that if it’s right there’s a Nobel Proze in it for somebody. Why not you?

Isn’t personal abuse forbidden on this blog?

The answer to your question can be found in the issue of feedback and how much and of what type exists in the atmosphere.

re 47

This might shed light on the issue that you raised.

Consider a control system for a car. The more drag on a car, the slower it tends to go. So, all things being equal, if a car moving on level ground at a certain speed reaches a hill, it will tend to go slower. Now equip that car with a cruise control system that uses feedback to maintain a constant speed. When the car reaches the hill, the cruise control commands more engine output and a constant speed is maintained.

Similar feedback mechanisms have been found in the atmosphere. Some act in the same direction as forcings which cause warming (positive feedback) and some act against it (negative feedback). The issue under scientific consideration is the balance between these different types of feedbacks and that balance will determine the stability ot lack thereof of the atmosphere against forcing such as increasing C02 concentrations.

Note that the fact that Earth’s atmosphere has relatively stable in the past is a strong argument for negative feedback since it is this type of feedback which produces stability. It tends to resist changes.

However, we can check the plausibility of the IPCC’s result by asking the following question: Instead of 33 degrees, what number would result if we calculated backwards from the IPCC estimates?

Using the same assumption of linearity, if a 9 degree increase resulted from the above-mentioned increase of greenhouse gas levels, the current greenhouse gas level (which is by definition 100%) would be equivalent to a greenhouse gas-induced temperature increase of at least 107 degrees C. This means the for the 9 degree figure to be correct, the current global temperature would have to be at least 255 + 107 – 273 = 89 degrees centigrade, or 192° Fahrenheit! A model that predicts a current-day temperature well above the highest-ever observed temperature is clearly in need of serious tweaking. Even a 5 degree projection predicts current-day temperatures of 41°C (106°F). These results clearly cannot be reconciled with observations.

The net effect of all these processes is that doubling carbon dioxide would not double the amount of global warming. In fact, the effect of carbon dioxide is roughly logarithmic. Each time carbon dioxide (or some other greenhouse gas) is doubled, the increase in temperature is less than the previous increase. The reason for this is that, eventually, all the longwave radiation that can be absorbed has already been absorbed.

I’ll have to cross-check on RC.

Although carbon dioxide is capable of raising the Earth’s overall temperature, the IPCC’s predictions of catastrophic temperature increases produced by carbon dioxide have been challenged by many scientists. In particular, the importance of water vapor is frequently overlooked by environmental activists and by the media. The above discussion shows that the large temperature increases predicted by many computer models are unphysical and inconsistent with results obtained by basic measurements. Skepticism is warranted when considering computer-generated projections of global warming that cannot even predict existing observations.

Cold Facts on Global Warming