I’m halfway through writing the 2nd post in the series CO2 – An Insignificant Trace Gas? – which is harder work than I expected and I came across a new video by John Coleman called Global Warming: The Other Side.
I only watched the first section which is 11 minutes long and promises in its writeup:
..we present the rebuttal to the bad science behind the global warming frenzy.. We show how that theory has failed to verify and has proven to be wrong.
The 1st video section claims to show the IPCC wrong but is actually a critique of one section of Al Gore’s movie, An Inconvenient Truth.
The presenter points out the well-known fact that in the ice-core record of the last million years CO2 increases lag temperature increases. And this appears to be the complete rebuttal of “CO2 causes temperature to increase”.
The IPCC has a whole chapter on the CO2 cycle in its TAR (Third Assessment Report) of 2001.
..Whatever the mechanisms involved, lags of up to 2,000 to 4,000 years in the drawdown of CO2 at the start of glacial periods suggests that the low CO2 concentrations during glacial periods amplify the climate change but do not initiate glaciations (Lorius and Oeschger, 1994; Fischer et al., 1999). Once established, the low CO2 concentration is likely to have enhanced global cooling (Hewitt and Mitchell, 1997)..
So the creator of this “documentary” hasn’t even bothered to check the IPCC report. They agree with him. And even more amazing, they put it in print!
If you are surprised by either of these points:
- CO2 lags temperature changes in the last million years of temperature history
- The IPCC doesn’t think this fact affects the theory of AGW (anthropogenic global warming)
Then read on a little further. I keep it simple.
The Oceans Store CO2
There is a lot of CO2 dissolved into the oceans.
“All other things being equal”, as the temperature of the oceans rises, CO2 is “out-gassed” – released into the atmosphere. As the temperature falls, more CO2 is dissolved in.
“All other things being equal” is the science way of conveying that the whole picture is very complex but if we concentrate on just two variables we can understand the relationship.
“All Other Things being Equal”
Just a note for those interested..
In the current environment, we (people) are increasing the amount of CO2 in the atmosphere. So, currently as ocean temperatures rise CO2 is not leaving the oceans, but in fact a proportion of the human-emitted CO2 (from power stations, cars, etc) is actually being dissolved into the ocean.
So in this instance temperature rises don’t cause the oceans to give up some of their CO2 because “all other things are not equal”.
Doesn’t the fact that CO2 lags temperature in the ice core record prove it doesn’t cause temperature changes?
It does prove that CO2 didn’t initiate those changes of direction in temperature. In fact the whole subject of why the climate has changed so much in the past is very complex and poorly understood, but let’s stay on topic.
Let’s suppose that there is an increase in solar radiation and so global temperatures increase. As a result the oceans will “out gas” CO2. We will see a record of CO2 changes following temperature changes.
But note that it tells us nothing about whether or not CO2 itself can increase temperatures.
[It might say something important about Al Gore's movie.]
More than one factor affects temperature rise. There are lots of inter-related effects in the climate and the physics and chemistry of climate science are very complex.
Whether or not the IPCC is correct in its assessment that doubling CO2 in the atmosphere will lead to dire consequences from high temperature rises is not the subject of this post.
This post is about a subject that causes a lot of confusion.
I haven’t watched Al Gore’s movie but it appears he links past temperature rises with CO2 changes to demonstrate that CO2 increases are a clear and present danger. He relies on the ignorance of his audience. Or demonstrates his own.
“Skeptics” now arrive and claim to “debunk” the science of the IPCC by debunking Al Gore’s movie. They rely on the ignorance of their audience. Or demonstrate their own.
CO2 is certainly very important in our atmosphere despite being a “trace gas”. Physics and the properties of “trace gases” cannot be deduced from our life experiences. Have a read of CO2 – An Insignificant Trace Gas? Part One to understand more about this subject.
CO2 is both a cause and a consequence of temperature changes. That’s what makes climate science so fascinating.