Tuesday
Mar192013
by 
Bishop Hill
Bishop Hill Don Keiller on plants and carbon dioxide
Mar 19, 2013 Climate: WG2 There has been some discussion in the comments about Don Keiller's undergraduate lecture about plants and carbon dioxide. Don has kindly sent over the slides, which can be seen here.
Reader Comments (77)
That sounds like an objection to splicing data with different averaging periods, not splicing per-se. Even I might understand... don't flatter yourself that you are more intelligent than I or any other contributor. The fact that I left uni to work in industry rather than staying on (in what many on the right here - though not I - consider a parasitic occupation) does not mark me as inferior. Like most here, I am your equal; don't forget it.
1500ppm is also the point at which the more vulnerable workers start to show breathing difficulties.
Mar 20, 2013 at 7:05 PM Entropic man "
1,500/1,000,000 = 0.0015
I have a US Navy report that says "(CO2)...Long exposures to 1.5% are tolerated without distress".
1.5/100 = 0.015 = ten times EM's figure.
Who is right - EM or USN?
[The CO2 in US submarines is normally regulated so it does not exceed 8000ppm - around 5 times EM's figure for some workers to have "breathing difficulties".]
BB what made you so bitter and twisted?
Just for the record I did not state or even suggest that I was superior, merely that you should go and check your facts before mouthing off about things you clearly know nothing about :-)
"...mouthing off about things you clearly know nothing about" - so what have I 'mouthed off' that is so clearly wrong?
Martin A
Your figures for submarine CO2 levels works fine for sailors, by definition fully fit individuals.
The link I gave includes a table of the health effects of varying CO2 exposures. I've copied it below, but it did not survive the process uncondensed.
The following table shows CO2 levels associated with various experienced discomforts.
Concentration Situation Symptoms and feelings
600 - 800 ppm Office or well vented dwelling
None
1000 ppm Acceptable level for closed room
Possible symptoms for asthmatics and beginning of « intellectual fatigue » for sensitive persons
1200 - 2000 ppm Many people in a poorly vented meeting room
Unvented bedroom occupied for 4-8 hours
Indoor garden enriched in CO2
Poorly vented or airtight house (air exchanger recommended)
Poorly vented office, factory, school room (more ventilation air exchanger recommended)
Yawning and drowsiness or dizziness
Asthma and previous symptoms increasing
5000 ppm High limit for a continuous exposure during 8 hours Only for tolerant persons
Previous symptons reinforced
6000 - 30 000 ppm Short exposure only Fainting possible prior to death*
3000 - 8000 Out of control indoor garden CO2 enrichment Breathing and cardiac rythms increase
10 000 ppm + Nausea, vomitting, dizziness, fainting
20 000 ppm + Fainting rapidly and death* is likely if nobody acts rapidly to get the affected person to breath less CO2 concentrated air
* CO2 being heavier than Oxygen, the latter is pushed up and replaced by CO2. Unconcious person lying down dies by suffocation.
If you run an enhanced CO2 greenhouse 1500ppm is the point at which you would need to start restricting access to intolerant individuals such as asthmatics. Above 5000ppm the rest of us start to become affected. Above that level workers need to wear filter masks to reduce their CO2 exposure.
Why is this cut and paste merchant bleating about humans and CO2 exposure? Has the megapedagogue never seen mechanised glasshouse production systems?
Facepalm.
"Yawning and drowsiness or dizziness" - beware: not just brought on by CO2.
Entropic Man, you clearly believe that CO2 is a highly toxic and planet-killing substance.
No amount of reasoned argument is going to persuade you otherwise.
But just mull this over. If you keeled over with a heart attack would you want someone to provide you with artificial respiration?
You need to bear in mind that you would be force-ventilated with expired air with a CO2 concentration of between 4 and 5%. That is 40-50,000ppm CO2.
Now compare these figures with yours.
20 000 ppm + Fainting rapidly and death* is likely if nobody acts rapidly to get the affected person to breath less CO2 concentrated air.
If you run an enhanced CO2 greenhouse 1500ppm is the point at which you would need to start restricting access to intolerant individuals such as asthmatics. Above 5000ppm the rest of us start to become affected. Above that level workers need to wear filter masks to reduce their CO2 exposure.
Mar 21, 2013 at 12:18 AM Entropic man
That contradicts the USN 8000ppm as OK in submarines - for long voyages, remember - essentially permanenet exposure..
EM - I don't know. I looked at your table (on a hydroponics site?) and could not find any reference to the original source of the data. I don't accept it without a link to something more authoritative. (I've seen too much BS produced in organsations I have worked for which was then modified when I insisted on knowing the source of the info and it being given as a reference.)
I remember learning, a long time ago, that it is is CO2 in the bloodstream that activates the breathing reflex, not shortage of oxygen.
I found a web page suggesting CO2 was benficial to asthmatics but I was not convinced it was authoritative - it had a slightly crank air.
There are numerous authoritative-looking references stating that 1.5% is tolerable for healthy individual (presumably because you don't use sick indviduals for such tests unless you are studying their illness).
I'll stick with 1.5% = 0.015 as generally tolerable even for people with breathing problems until I come across authoritative data saying otherwise.
Cat got your tongue, Don Keiller? Come on you said I was mouthing off about things I know nothing about, so what did I get wrong? I don't claim any expertise in anything relevant here, so it is quite possible I goofed. But then I am not presenting lectures with graphs that seem pure fantasy. You seem reluctant to defend your 4bn year temperature graph and the inferences you draw from it. I'm not surprised - you could probably invert the curves and have just as much chance of it being right for anything beyond 100 million years. I don't suppose anyone here will think any worse of you if you admit it is all conjecture rather than fact - and I would think better of you for it.
Martin A
This is the best I can do as a direct reference to the HSA regulations.
http://www.hse.gov.uk/carboncapture/carbondioxide.htm
My original link was to a site advising hi-tech greenhouse operators. They use hydroponics, CO2 enrichment and a variety of other technologies. Whereas a submarine fleet can screen potential crewmen for high CO2 tolerance, I'm not sure a horticulture business can do the same for its workers.
I'm still looking for the original source of the tolerance figures I gave you. I've tried various sources, and they all have similar figures. One more before we close the topic.
http://www.dhs.wisconsin.gov/eh/chemfs/fs/carbondioxide.htm
Bit Bucket, do you work on the set of East Enders. You sound vicious enough.
EM - thanks for the references.
One lead to http://www.cdc.gov/niosh/pdfs/76-194b.pdf which has summaries of numerous tests (some sounding to me totally unethical). If you read that (80+ pages) you'll know a lot about the subject.
I don't have time to read it now but skimming through, I did not see anything suggesting 1% was a hazard to anyone. 3% definitely produces effects. One snippet suggested asthmatics had a greater tolerance than healthy individuals.
Obviously, an agency setting safety standards will play for safe by specifying a lower limit than the maximum beleived to be safe.
I can assure you that navies don't select submariners for high CO2 tolerance. (If it were an issue, I presume they would simply operate with lower CO2 limits - not hard to do.)
As you say, let's leave it at that.
Bitbucket, if you spent as much time looking into and criticising to the profound problems with Mann's and Marcott's climate reconstructions, as you have with my lecture (which by the way the students enjoyed) I would take you seriously.
Until then......
"One snippet suggested asthmatics had a greater tolerance than healthy individuals."
There are one or two websites for asthmatics saying they can benefit from learning to breathe slower, less deeply, to increase the CO2 level in their lungs.
Don Keiller, your lecture notes are interesting - written to get across your political views rather than from a purely scientific point of view, one might say, but that's ok; I imagine your students are aware of your politics. Much of the detail is new to me, though the themes are not; the page about flooding looks rather rich-world-centric for a worldwide map (there's plenty of floods where I am and its not on the map), but hey-ho. But the temperature curve really struck me though and as I had nothing better to do I looked for the source. It really didn't take any time to find as the names are at the bottom and I just checkup the first one (Scotese). I found that there is remarkably little supporting the curve or the values and this made me wonder how you can be so sure about the conditions at your significant points. You seem so sure of them so it should be easy to prove their validity - for example, you could quote the peer-reviewed publications in which these assertions are made, preferably several, as we all know science depends upon independent confirmation. I don't believe you can do that and your reluctance to defend your assertions makes me doubly sure. But if you can defend them satisfactorily, I promise to spend at least a day researching Marcott.
Martin, I hope you never get an asthma attack. If you are unfortunate enough to suffer a bad one though, I assure you that the last thing you will think about is breathing slowly to increase your CO₂ levels.
BB:
http://www.academia.edu/2046360/Hypocapnia_and_Asthma_A_Mechanism_for_Breathing_Retraining
OK BB this is my final try at reason.
My famous slide 8 is derived from this paper
Rothman, D.H., Atmospheric carbon dioxide levels for the last 500 million years Proceedings of the National Academy of Sciences 99 (7): 4167-4171, (2002).
Here is part of the abstract
"The last 500 million years of the strontium-isotope record are shown to correlate significantly with the concurrent record of isotopic fractionation between inorganic and organic carbon after the effects of recycled sediment are removed from the strontium
signal. The correlation is shown to result from the common dependence of both signals on weathering and magmatic processes. Because the long-term evolution of carbon dioxide levels depends similarly on weathering and magmatism, the relative fluctuations
of CO2 levels are inferred from the shared fluctuations of the isotopic records. The resulting CO2 signal exhibits no systematic correspondence with the geologic record of climatic variations at tectonic time scales."
And for drought
Sheffield, J., Wood, E.F. and Roderick, M.L. 2012. Little change in global drought over the past 60 years. Nature 491: 435-437.
Here's some non-rich world centric stuff for Floods
Zha, X., Huang, C., Pang, J. and Li, Y. 2012. Sedimentary and hydrological studies of the Holocene palaeofloods in the middle reaches of the Jinghe River. Journal of Geographical Sciences 22: 470-478.
I'm fed up of spoon-feeding you. Go away and actually do some real background research, rather than chuck hearsay around "there's plenty of floods where I am and its not on the map, but hey-ho".
"written to get across your political views rather than from a purely scientific point of view, one might say"
Translation: Bitbucket might say that.
"I promise to spend at least a day researching Marcott"
It takes less than an hour, and the fact that you haven't done it yet is very telling.
I don't get proper asthma attacks any more, but I still get an occasional wheeze. It can indeed be countered by shallow nose breathing and rebreathing exhaled air. It isn't as good as a shot of salbutamol, but it works. I make no claim that this is down to CO2, or that it would work in the case of a severe attack, in which case as BB hints you are more concerned with staying alive.
As a pure speculation, humans may not be designed for 280ppm as an optimum. I don't know how you'd check that though.
Don Keiller, the CO₂ paper you referenced gives very a different curve from the one you used and also starts several hundred million years later. And a quick search gives other curves and one paper that finds a huge spike at the KT boundary - which doesn't show up on others. I get the impression that historic CO₂ levels, like temperatures, are essentially unknown beyond handwaving generalities. So much for your correlation with major evolutionary events.
My "hearsay" is not the point. You have a maps that says "Floods- Worldwide" that has a hundred or more data points in Europe and the USA and about 10 in the rest of the world. There may or may not be a worldwide increase in floods, I have no idea, but your map and any research that draws conclusions from it are insufficient evidence. You must see that it looks silly.
Rhoda, my asthma also subsided substantially in my 20's, but I have heard it can return in old age. Not looking forward to that...
BB I'm fed up of feeding what is obviously a troll.
Check back at what I said "My famous slide 8 is derived from this paper".
Derived, not identical.
You might be interested to know that the main reaction from my students was
"Why haven't we been told this before?"
I'll tell you- because they have been subject to a misinformation campaign, funded by the state, which you have obviously swallowed hook, line and sinker.
Made any progress in your "research" into the Madeup, Shaken, Clart and Mix (2013) paper?
Derived? Readers can look at the two images, the derived version on the right (thin grey line) and get gold stars for determining the derivation function, which must involve stretching to somehow get another 500 million years. Not told it before? You bet!
BB Any comment on Marcott?
I thought not :-)
Well, the paper seems to be pay-walled. But Tamino has some interesting posts on it...
Don Keiller
Sorry for the delayed response - I was going to answer this the other evening, but when I logged on I saw the Bish's tweet about the latest Lewandowsky paper and got somewhat distracted.... :-)
Anyway - yes, I stand by my comments of 4C or more global warming being possible by the end of this century, with local warming higher in some places, up to 15C in the Arctic an extreme but plausible case.
Nevertheless the evidence also suggests that the impacts of anthropogenic climate change on droughts, crop production and vegetation may not be as severe as some people think, due to the beneficial effects of increased CO2 concentrations.
I have been drafting (with others) the IPCC WG2 AR5 discussion on the role of CO2 in affecting land ecosystems and the knock-on effects on hydrological impacts. If you'd like to review this, please email the WG2 technical support unit on tsu@ipcc-wg2.gov . The review of the Second Order Draft opens on 28th March.