He said, among other misleading statements:
Then an Ice Age occurred 450 million years ago when CO2 was 10 times higher than today.'How do I know Moore purposely misled Congress? Because I corrected him on exactly this point on Twitter a few months ago. And he simply ignored all that science.
It is true that an ice age occurred about 450 million years ago -- the Ordovician–Silurian ice age.
But little is known about CO2 levels at that time -- as I pointed out to Moore on Twitter -- and what's even more significant is that the Sun was weaker than by about 4%. And the continents were in different places, meaning the planet's albedo was very different from today.
Moore ignored all this in order to pretend that the O-S ice age means CO2 is an insignificant greenhouse gas.
The Sun's irradiance increases by about 1% every 110 million years. (See the top equation on page 4 here, or Pierrehumbert's textbook pg 12 equation 1.1.) So 450 million years ago there was about 54 W/m2 less sunlight impinging on the top of Earth's atmosphere.
That's a huge amount. By comparison, recall that anthropogenic CO2's radiative forcing is now only about 1.9 W/m2.
The continents were in places nothing like where they are today. The Earth's albedo (reflectance) would have been signficantly different.
But if the Earth's albedo then was the same as today's, 0.3, it would have taken lots of CO2 just to counteract the weaker Sun. You can calculate this easily:
(1-albedo)*ΔS/4 = CO2's RF = 5.35*ln(CO2/today's baseline CO2)
or CO2 = 1640 ppm. That's with no albedo change (unlikely), just to get the same average global temperature as today (which includes our ice sheets).
Even worse, we really don't know what CO2 levels were back then. On Twitter Moore casually tossed around the cartoon to the right:
The problem is, there is very little data from back then -- proxy data points are about 10 million years apart -- and these curves come from carbon cycle models, which are much more uncertain than, say, today's climate models.
(Carbon cycle modeling is an integral part of climate models, but also their biggest uncertainty.)
This excellent review article by Dana L. Royer of Wesleyan covers CO2-forcing during the Phanerozoic -- the last 541 million years of Earth's history.
|From Royer, Geochimica (2006). |
Today is at the far right of the horizontal axis;
intervals are 100 M yrs backwards.
The best-regarded model of this class that predicts CO2 for the full Phanerozoic is GEOCARB, which has a time-step of 10 my (Berner and Kothavala, 2001); this means that CO2 fluctuations operating at timescales shorter than 10 my may not influence GEOCARB.10 million years between time steps. A huge amount can happen in 10 million years. Look how much CO2 changed during the PETM, and that was only about 200,000 years.
By the way, the O-S ice age lasted only 0.5 M yrs.
In fact, Royer says that 4% lower sunshine means the glaciation threshold rises from 500 ppm today to 3000 ppm then. Dr. Patrick Moore completely ignored that knowledge.
So the cartoon is very misleading, without error bars in either the vertical or (especially) the horizontal direction.
Moore ignored all this. He wanted to paint a certain picture -- that CO2 is not very relevant -- and he was doing to do that with or without science.
In this case, mostly without.
These are the kind of rogues we have testifying before Congress on the most important issue of our day.
Update: SkS wrote about the O-S ice period here.
Have you forwarded this to the members of the committee that he testified to?
No. But I'm thinking about it. On paper. (I doubt email would be noticed with Congresspeople.)
I appreciate your information here, but request that you correct the false information in its first sentence.
Patrick Moore was not a "Greenpeace co-founder." He did work for Greenpeace in the early days of the organization, but this claim of being a founder is false (like so many other things Moore has said).
And although he has not been involved with the organization for many decades, this post leaves the impression that he somehow represents Greenpeace. Could you please correct this as well?
Moore continues to talk about the old connection in order to gin up more attention than he would otherwise receive.
You can find more information about Moore from Greenpeace's viewpoint here: http://www.greenpeace.org/international/en/about/history/Patrick-Moore-background-information/
Greenpeace originally listed Moore as a co-founder on their web-site but has revised it's own history by removing this detail. It is dishonest to hide this just because it is embarrassing for them. Trying to alter the truth looks dodgy.
BF: Please follow this link to see a copy of Patrick Moore's request to join in a Greenpeace voyage, about a year after the founding of the organization: http://www.greenpeace.org/international/Global/usa/binaries/2008/12/patrick-moore-s-application-le.pdf
So what? He's still very wrong about climate science.
YES, he is very wrong about climate science. And about the nuclear industry and logging...and other subjects he is hired to expound upon.
"So what" is that your post suggests he speaks for an environmental organization when he does not.
Patricia, I misunderstood your remark. Sorry.
Found the correction:
Thank you for that.
"Total solar irradiance in the past is difficult to determine and may—for the period since
the Maunder Minimum (associated with the Little Ice Age) of the mid-1600s to the early 1700s—
have an uncertainty of anywhere from 1 to 15 w/m2."
If the uncertainty 300 years ago is 1-15 w/m2, what is the uncertainty 450,000 years ago?
You claim Moore was wrong to use an estimate of 2000 ppm CO2 in his testimony. However, he was using an estimate made by Pagani and others, published in 2005 in Science Magazine.
The abstract can be found here:
It sounds like your quarrel is not with Moore, but with his source of information. However, Pagani's research has been cited dozens of times in many other studies. Sounds like it has been widely accepted.
You used a study by Royer to dispute Moore's estimate. However, Royer's data does not lead one to believe Moore's CO2 estimate was too low. To the contrary, Royer's data support's an estimate 2 or 3 times HIGHER than Moore (and that's a conservative reading).
So, all evidence in your blog post seems to support Moore, rather than you. And yet, you call Moore all sorts of names and accuse him of dishonesty.
(1) Where is your supporting evidence that CO2 levels 450,000 years ago were DEFINITELY and SIGNIFICANTLY lower than Moore's 2000 ppm estimate?
(2) Where is your supporting evidence that total solar irradiance was anywhere close to your calculated figure, given the huge uncertainty cited by Marsh?
(3) Whatever happened to RESPECTFULLY disagreeing with someone, especially when the evidence you cite as reason for your disagreement is SO WEAK?
You completely missed the point.
The point is that, with a weaker sun in the past, it takes higher CO2 to create the same temperature as today.
So saying CO2 then was 2000 or 4000 ppm says nothing on its own, without taking into account the weaker sun, and the albedo difference from today (since the continents then were different and in different places).
PS: Moore said CO2 then was 4000 ppm then, not 2000 ppm:
"Then an Ice Age occurred 450 million years ago when CO2 was 10 times higher than today"
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