There's also evidence that CO2 lags temperature increase historically, meaning CO2 was not the causative agent for temperature increase, rising CO2 might be an artifact of increase temperatures.
At that point you're questioning pretty basic physics. What part of the influence of CO2 concentration on the infrared transmittance of the atmosphere are you questioning [0]? Extraordinary claims require extraordinary evidence.
The "basic physics" contradicts the data. Your error is approaching this enormously complex question with the assumption that climate science is unquestionably correct. This lag is a glaring discrepancy that begs resolution. No, it doesn't mean climate science is totally wrong, but this attitude of unquestionability is absolutely pervasive in both society at large and academia, and gives deniers a justifiable reason for suspicion.
And I'm not some snot nosed programmer looking in from outside. I'm a former geoscientist and I saw this pressure firsthand, even at a relatively conservative University.
It is of course totally possible and consistent with mainstream climate science for CO2 levels to trail temperature under some conditions, for example when the temperature is driven by Milankovich cycles. [0]
I was attacking the implied invalid conclusion that rising CO2 levels would therefore not drive temperature.
But, to address the point in more detail, look at the data in [1]. CO2 typically does not lag temperature. If you cherry-pick points in time at the beginning of a Milankovich-induced temperature increase it may, and this is adequately explained by outgassing of CO2 from the oceans, driven by the sun. [2]
> [...] this attitude of unquestionability is absolutely pervasive in both society at large and academia, and gives deniers a justifiable reason for suspicion.
I try to find citations for what I write here, and address specific points, both to teach myself the science and to keep the discussion honest. If everybody here did this there would certainly be no "attitude of unquestionability".
I agree that it can probably seem that way on cursory look. I personally find it hard to always keep cool when faced with a barrage of pseudo-scientific points that don't hold up to scrutiny. More importantly, I find the implicit arrogance really hard to stomach, i.e. thinking that a huge field of scientists is too stupid to understand some "obvious fault" that someone posted on their blog. Maybe that makes me unfair to some participants who are just trying to understand the issue better and / or have an honest discussion. I'm sorry if that was the case.
I don't get it. Climate change critics try to find one flaw in some straw man argument and then denounce the whole field as a lie. CO2 isn't the only thing that causes warming and no, scientists are not stupid enough to not account for these things. I mean this statement is trivial to disprove because methane and tons of other things also act as greenhouse gases or amplify heating. It doesn't change the threat caused by higher temperatures. 4°C are 4°C and we can bet on going way beyond that tiny puny number if no ones gives a damn.
It's one flaw of many. First, nobody really trusts the temperature data. Second, the earth was much hotter before. Third, there was an ice age, now there isn't, planet was already warming. Fourth, water vapor is recognized as the most powerful greenhouse gas. Fifth, we don't believe solar energy is being adequately accounted for.
We have a what we consider a lot of holes, big import holes, in the theory. These issues are immediately dismissed. The fact that people can say with a straight face that water vapor increases global warming, yet is not the primary cause, even though it's the strongest greenhouse gas, is beyond believe. It defies comprehension, I will never, ever take the CO2 theory serious, and I'll be here encouraging others to think for themselves as well.
[0] https://en.wikipedia.org/wiki/Greenhouse_effect#Mechanism