Going into something that I STILL don't understand that hasn't been explained to me is if CO2 always results in higher temperatures when it increases (as you seem to be saying, yes?) and increasing the overall temperature which releases even more CO2 from the vast oceans, why is it that it doesn't get stuck in a perpetual positive heat->CO2->heat cycle? Also, if the chart referenced later on in this topic is correct that the CO2 has been an order of magnitude higher in the past with similar temperatures, that still doesn't make sense.
Further, with the 800 year lag if CO2 always acted the way you describe in the environment it doesn't make sense that we'd see periods of high CO2 with low temperatures.
Considering that the Earth has been around for several billion years and hasn't gotten fried yet, it only seems logical that there are some natural processes that allow the Earth to stay cool even if the CO2 is high as it has in some past instances. Which is why I keep saying it's ridiculous to ignore the past 6 billion years.
Positive feedback doesn’t always result in a runaway condition, it can also result in converging on a value muck like an infinite series that converges on a finite value. We also have an example of runaway greenhouse effect right next door to us on the Planet Venus.
Those points aside there really are strong negative feedback elements in the Earth’s climate. Doubling of CO2 leads to somewhere between 1.5 – 4.5 deg C warming, so lets say ~3 deg C. To get 6 deg warming you need to have an 4X increase in CO2, and to get 9 deg you need an 8X increase. This diminishing return on increasing CO2 levels gives those negative feedback elements plenty of time to overtake CO2 in importance, just not until significant warming has already occurred.
While these negative feedback elements prevent runaway greenhouse effects they can’t reduce the warming from CO2 to zero as some people claim. Look at it this way, if temperature warms due to CO2, and this warming cases more clouds which reflect sunlight thus cooling the atmosphere what happens if you cool back to the original temperature? The cloud formation stops, the cooling effect disappears but the warming effect from CO2 is still present.
Clearly this doesn’t work. What really happens is that the climate finds a new equilibrium temperature where greater cloud formation balances the new warming effect from CO2. This temperature must be greater then the original temperature, but won’t be as great as if there was no negative feedback.
The way climate sensitivity is calculated actually includes negative feedback effects at their current values because the calculation is based on observed (closed loop) changes, rather then calculating a theoretical value for warming and feedback and merging them. Since climate isn’t linear this only works well for conditions near those you did the calculation for but it’s generally an acceptable approximation.
In that case, you should fully understand that some slight errors in code can create massive issues with output if you aren't careful enough. There are entire volumes of publications dedicated to training programmers how to keep bugs out of code and yet buggy code is still written all the time. It's perfectly reasonable to ask for code.
I also learned that if my results agreed with the independent results from rest of the people in the class there was little chance of a significant coding error. If is simply showed them my code, however the chances that the same coding error would be present in multiple projects was greatly increased. Showing my code also resulted in having to field many questions about why I did something a certain way, questions that were a moot point when independently written code produced identical results.
A logic error was certainly still possible if multiple people misunderstood the same point. The methodology needed to find such a logic error is already publicly available.
The fundamental problem I have with McIntyre’s approach is that it’s only capable of providing a negative answer. I.E. it can be used to say “this isn’t the case” but it can never say “this is”. It can never provide positive evidence. Furthermore, if pushed hard enough it can be used to claim anything is false. It’s a good tool for “falsifying” real science and a poor tool for drawing any real conclusions. Being able to provide strong positive evidence of something as good or better at explaining the phenomenon is question is a key part of any scientific debate.