No, they also are concerned about the magnitude. See the Summary for Policymakers from AR5: “Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. The period from 1983 to 2012 was likely the warmest 30-year period of the last 1400 years in the Northern Hemisphere, where such assessment is possible (medium confidence).” https://www.ipcc.ch/report/ar5/syr/
The narrative promoted by the IPCC is that CO2 levels were low and steady until the Industrial Revolution. From then on CO2 levels have been increasing steadily. But there are good reasons to doubt this is true. First, CO2 measurements from the 1800’s through the 1950’s are variable, ranging from 250 to 550 ppm. But the venerable Guy Calendar, patron saint of global warming, cherry-picked measurements which fit his narrative and tossed the rest. Second, measurements of CO2 for earlier times largely come from ice-cores, and there are good reasons to believe that ice cores measurements suppress variability of CO2. Third, the Siple curve, which has been invaluable in supporting the IPCC CO2 narrative, turns out to be bogus. As explained by Zbigniew Jaworski, researchers wanted ice core measurements from Siple Antartica to link up with the rising atmospheric CO2 measurements from Mauna Loa Hawaii. The problem was that the Siple measurements rose too soon. Their solution was to move the Siple measurements 89 years ahead so they could hook up with Mauna Loa measurements!! To this day proponents of the CO2 theory use this bogus graph. See for example Kerry Emanuel, who calls the result “nicely congruent.” [
That CO2 has greenhouse properties is undeniable. Adding CO2 to the atmosphere should cause some warming, and once can even calculate how much warming assuming all other factors are held constant. But all other factors are never constant. So the issue is how sensitive the climate system is to added CO2, and the verdict so far is not very much.
Contemporary CO2 concentration measurements are not the only source of our overall estimate of CO2 in the past. There are also ice cores (as you mentioned below) and proxies such as ocean sediments and micro fossils. There is no serious doubt about the fact that CO2 levels have been below 300 ppm until the industrial revolution. If you have a scholarly article that says otherwise, please cite it. Of course CO2 was much higher in prehistoric times, but that was when the climate was vastly different too, so no conclusions can be drawn from that.
Please cite a scholarly article that says that ice-core data is not good enough to conclude that CO2 was below 300.
I had not heard this claim before, and was unable to confirm it by searching. Please tell me where you got this info so I can see what this is about, if anything. I looked at 28:30 into the youtube video you cited and it confirmed that there is no dispute the CO2 has risen suddenly and dramatically during the industrial revolution. So I don’t know what sort of fraudulent results you are claiming has happened.
Nope. Tis a controverted issue.
Not good enough.
In reading the testimony given by Jaworrowski, it became apparent to me that his argument turned on highly technical details of instrumentation techniques that only an expert in the field can rightly confirm or deny. Therefore it is important for me, as one who is not an expert in CO2 reconstructions from ice cores, to see whether or not his argument stands up to scrutiny by his peers. If you could please cite where this has happened I would then know whether to give his opinion real consideration, or to temporarily discard it pending such review. I also ask you why exact portion of the youtube video you cited earlier tells exactly the opposite story.
I would be more convinced if you cited actual peer-reviewed publications, not books of someone’s agenda. Ditto for your “definitive takedown” that you cited in the subsequent posting. Please do not cite youtube videos. They are a cop-out from actual written arguments that can be read at my own pace.Regarding the third element of the GW hypothesis I said:
Third, human CO2 emissions from the burning of fossil fuels are the primary cause of rising CO2.
You replied:
LeafByNiggle:
Nope. Tis a controverted issue.
Robert Carter–may he rest in peace–disagrees with your and the IPCC’s conclusion. See his book Climate–The Counter Consensus.
Hi LBN,
Personally I am a little suspicious of a book unless I can check out the claims it makes myself. Otherwise I am afraid that my non-expert intuition can be too easily misled by convincing sounding arguments that make no scientific sense. That is, they might not make any scientific sense but I would have no way of knowing that unless I was myself active in that field of science. Deciding between authors would come down to who is the best BSer. That is why I rely on the wisdom of the those who have the knowledge and skill to evaluate those claims. On those rare occasions when my own knowledge is sufficient to evaluate a claim, I do so.
I do not question the sincerity of skeptics, only their scientific accuracy. So there does not appear to be any reason to inquire into their “mindset.”
The fact that he has more than a few lectures on youtube in itself is no guarantee of authority.
Since I do not fully understand the role of residence time of CO2 in the application of isotope analysis and fossil fuels, I don’t know if an incorrect assumption here says anything against the theory that modern CO2 comes mostly from fossil fuels. Also, it seems the question can be answered approximately by calculating the amount of CO2 that would come from the fossil fuels that we know about. We have a pretty solid estimate of that, don’t we? If it isn’t going into the air, where is it going?
I could not find a reference to that on Google. Guess I have to have a hard copy. Is it a peer-reviewed journal?
I have the same problem. Spencer’s claims are too technical for me to evaluate on my own.
I do not question your honesty nor am I supporting all of Obama’s policies on global warming. I separate the scientific question of climate change from the political question of what to do about it. Even though they are closely related, they do require different approaches.
The same to you!