Bishop Hill Optimum carbon dioxide levels
May 21, 2011 Climate: HSI Climate: WG2 Climate: other Princeton physicist Will Happer wonders what the optimum level of carbon dioxide is:
We conclude that atmospheric CO2 levels should be above 150 ppm to avoid harming green plants and below about 5000 ppm to avoid harming people. That is a very wide range, and our atmosphere is much closer to the lower end than to the upper end. The current rate of burning fossil fuels adds about 2 ppm per year to the atmosphere, so that getting from the current level to 1000 ppm would take about 300 years—and 1000 ppm is still less than what most plants would prefer, and much less than either the nasa or the Navy limit for human beings.
The Hockey Stick Illusion is mentioned too:
The IPCC and its worshipful supporters did their best to promote the hockey-stick temperature curve. But as John Adams remarked, “Facts are stubborn things, and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.” The hockey-stick curve caught the attention of two Canadians, Steve McIntyre, a mining consultant, and an academic statistician, Ross McKitrick. As they began to look more carefully at the original data—much of it from tree rings—and at the analysis that led to the hockey stick, they became more and more puzzled. By hard, remarkably detailed, and persistent work over many years, consistently frustrated in their efforts to obtain original data and data-analysis methods, they showed that the hockey stick was not supported by observational data. An excellent, recent history of this episode is A. W. Montford’s The Hockey Stick Illusion.
Reader Comments (13)
That's the first time I've seen someone get SteveMc's job description right. Ross, though, I think is an economist and therefore a statistician.
Joseph Postma (http://www.tech-know.eu/uploads/Understanding_the_Atmosphere_Effect.pdf) suggests:
See comment #47 @ http://joannenova.com.au/2011/05/so-what-is-the-second-darn-law/comment-page-3/#comment-311853
Tomato growers feed their polytunnels with CO2 to a concentration of 800-1000ppm. No tomato industry workers known to have keeled over as a result...
A very good article by Dr. Happer. Well worth the time it tokk to read. Reading this article should be mandatory for all politicians.
Over 1000ppm in the tomato houses I worked in. The plants loved it, and I'm still here.
"as John Adams remarked, “Facts are stubborn things, and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.”" Americans have always been verbose, then?
On another forum I frequent they were discussing the doomsayers in the US suggesting the end of the world ... errrrr .. yesterday.
I find it interesting that none took them seriously, yet take a doomsayer suggesting the end of the world in 2100 as very serious indeed. The people making the claim have nothing significantly tangible to demonstrate, have by physical observation got it wrong on many occasions in the past. They have continually "moved the goalposts" - yet the "people" still believe every word spouted through the media.
They fail to raise any questions regarding the claims, if offered alternative views refuse to believe them.
@stephen lewis,
Probably a bit insensitive to say, 'Cheer up, it's not the end of the world'?
Interesting article by Will Happer, but I'd note that I'd rather not experiment with very low CO2 levels thank you. I think many climate scientists could benefit from studying a bit of human/mammalian physiology. The evolution of the pulmonary system suggests that all of their shrill hysteria about deadly pollutants is somewhat misplaced.
From wikipedia, an example - 'In other words, CO2 is the driving force for breathing.'
i.e. it controls the breathing reflex....
Koeslag explains it rather well -
http://sun025.sun.ac.za/portal/page/portal/Health_Sciences/English/Departments/Biomedical_Sciences/MEDICAL_PHYSIOLOGY/Essays/pulmonary_physiology
e.g.
'Modern ambient air is highly toxic to a great many creatures including all vertebrates'
'Instead, the pulmonary dialysate resembles the earth's atmosphere of about 400 - 500 million years ago: poor in oxygen, but rich in carbon dioxide. It probably also resembles that fossil atmosphere in being warm and humid.'
His other essay 'What is Life' is worth a read as well.
Chuckles
"CO2 is the driving force for breathing*
Do you remember Jonathan Miller's demonstration in "The Body in Question"?
http://www.youtube.com/watch?v=X3dDQQcWhyU
Dreadnought, No don't know the series at all. I shall peruse :)
I'm way out of date and out of sync with the climate blogosphere but I did notice this article by Happer yesterday and felt that it was a terrific advance from previous, take-it-from-the-top presentions from a scientist. I've always had a soft spot for Mitch Decter at First Things - though I'm sure she's blissfully unaware of the fact! - so all credit to the author and editor of this important piece.
And at the same time I was catching up with Matt Ridley's latest in the Spectator through Delingpole - again, a brilliant summary, this time on the policy based on the science (using the terms 'based on' and 'science' in their loosest senses of course):
http://www.spectator.co.uk/essays/all/6954843/a-green-dark-age.thtml
(Sorry if that's already had a posting here Bish but there's little time ...)
I have a number of as yet unaligned people in mind as I think that these two pieces significantly change the infowar, as one American puts it. (I don't endorse everything by that Jones, any more than the one from CRU, but it's a compelling neologism.)
Midge Decter that should have been. How embarrassing :)
Will Happer might be out on the time taken for CO2 levels to reach 1000ppm. At present CO2 levels are increasing by around 2ppm per year, but the rate is accelerating each year. The Mauna Loa CO2 measurements only go back to 1959. In that time the annual increase in CO2 levels has been accelerating - by my estimate by .0309ppm per year. So the 1000ppm level is only 140 years off, and the dangerous 5000ppm level is reached in the decade before 2500. Less than 489 years to save the world then.
Related to this, the skeptical science blog has a nice equation to help recast this CO2 Levels into IPCC warming terms. It nicely calculates that a doubling of CO2 will lead to 3 degrees of warming (well 2.967).
This is only 57 years off. By the end of the century, with CO2 at 700ppm, we get 4.9 degrees of warming. 1000ppm equates to 5.4 degrees and 5000ppm just 12.4 degrees.
If if this equation is correct, there is still the problem of extrapolating over long periods. It is highly unlikely that CO2 levels will ever get anywhere near the critical 5000ppm level - and the warming forecast relies on positive feedbacks amplifying the pure CO2 impact by a number of times.
http://www.skepticalscience.com/pre-1940-warming-causes-and-logic.html