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A couple years back I read the IPCC reports trying to find out if global warming was real or not. I noticed the Vostok ice core data in the earlier reports showed the temperature rose first and then the CO2 rose. Likewise, the temperature fell first and then the CO2 fell later on. They fixed this little inconvenient data problem in the later reports.

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The following is literally the first Google result for "why does CO2 concentration lag behind temperature".

http://www.skepticalscience.com/co2-lags-temperature.htm

> ... This statement does not tell the whole story. The initial changes in temperature during this period are explained by changes in the Earth’s orbit around the sun, which affects the amount of seasonal sunlight reaching the Earth’s surface. In the case of warming, the lag between temperature and CO2 is explained as follows: as ocean temperatures rise, oceans release CO2 into the atmosphere. In turn, this release amplifies the warming trend, leading to yet more CO2 being released. In other words, increasing CO2 levels become both the cause and effect of further warming. This positive feedback is necessary to trigger the shifts between glacials and interglacials as the effect of orbital changes is too weak to cause such variation.

In the Vostok data the temperature falls first and then the CO2 falls. If the CO2 released amplified the increased warming trend then why would the temperature suddenly reverse absent a CO2 drop?

BTW, I am really really disappointed in the quality of all the replies. It's mostly ad hominem and hand-waving. This is the one reply that's not but it doesn't explain the behavior of the drop in temperature.

Thus to sum it up:

Increased temperature causes gas to become less soluble in the ocean, thus leading to increased CO2. Decreased temperature causes CO2 to become more soluble in the ocean thus leading to decreased CO2. This data shows then that CO2 increases are not enough to cause warming all by themselves or to prevent cooling all by themselves.

Obviously a very large amount of CO2 in the atmosphere will lead to warming (e.g Venus's atmosphere is 96% CO2) but we're many orders of magnitude off from that (0.04% CO2).

So we are left with what I like to call a Listerine argument: Listerine has been selling more over the past century, Listerine prevents tooth decay, thus Listerine is the cause of the improvement in dental health over the past century. Thus we should put Listerine in the water and implement a global tax so everyone can have Listerine.

You might be interested in the opinion of Richard Muller:

In 2010, I watched one of his talks in which he had very uncharitable things to say about some groups of climate scientists and why he did not consider them trustworthy [1].

At about 34:28 of the video, you can hear him say the following:

This is why I'm now leading a study to redo all this in a totally transparent way.

He did [2].

What was his conclusion? Global warming is real, and in all likelihood the culprit is indeed CO2.

How did he come to that conclusion? Because it's the only proposed mechanism for global warming that actually fits the data on the 250y scale.

[1] https://www.youtube.com/watch?v=VbR0EPWgkEI

[2] http://berkeleyearth.org/

This is not an inconvenient data problem. That the ends of past ice ages were not caused by a rising atmospheric carbon dioxide concentration but instead caused it with some lag does not at all proof that a rising atmospheric carbon dioxide concentration can not cause rising atmospheric temperatures.

For example - completely made up - a change in the orbit of the earth could cause rising temperatures and therefore the end of an ice age. This could then free carbon dioxide trapped in or under the now melting snow and ice and in turn this change in the composition of the atmosphere could additionally contribute to the rising temperatures.

This is hardly unexpected. As water warms, the solubility of various gases decreases. I.e., if you exogenously warm up the ocean, it will release CO2 and other trace gases into the atmosphere. I'm pretty sure you could get the same pattern for Argon and other (non-greenouse) trace gases.

I'm sure the IPCC has flaws, like every other human institution (but what else do we have to work with?), but the original reports came out in 1990. Also, every data set ever produced has inconsitencies.

I don't feel that one inconsistency from 25 years ago, which might have a valid explanation or might be validly considered inconsequential, undermines the IPCC reports' credibility.

So, that's an interesting phenomenom, albeit one with possible explanations (that others have provided), but I'd like to volley a question back to you: have you performed the same experiments that Arrhenious[1] performed in 1896, that has been reproduced thousands of times before, and come up with a different result? (ie, that CO2 doesn't create a greenhouse effect).

[1] - https://en.wikipedia.org/wiki/Svante_Arrhenius#Greenhouse_ef...

Ugh. This is exactly the type of poorly-informed response you generally get when people attempt to "read the data" for themselves with little to no understanding of the science behind it. Seems to be a lot of that going around HN today.

It's exacerbated when it's less someone reading it for themselves, than reading it in a blog post by someone who's motivated to try to strip context and mislead about results.

Please try to be specific in your criticism. What misunderstanding does the above poster have about the science or the data?

Well, for one, that their uneducated skim through the IPCC report found a mistake which thousands of qualified scientists had missed, one so fundamental that it undermines all of the rest of the work in the report and the conclusions it leads to.

The scientists say so, therefore the commenter is wrong? This still doesn't explain why the above is wrong. Attacking the premises of an argument is sound logic, and should be welcome. Ad hominem arguments should be called out.

Your comment reminds me how the Catholic Church treated the Bible during the Middle Ages (environmentalism runs so parallel to religion it's uncanny).

The clergy would not let lay people read the Bible themselves, claiming there are "poorly-informed responses you get when people attempt to read the scripture for themselves with little to no understanding of the theology behind it."

"Just trust us," they said, "we will interpret it for you and tell you how to live accordingly."

The sad thing is, some people who aren't particularly familiar with scientific practice will read this as damning, while in reality it's anything but.

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