Bishop Hill Plant food
Aug 17, 2010 Greens The argument that carbon dioxide is plant food and that we should welcome increased concentrations of the stuff as leading to bumper crop yields is one that is not given much credence by the other side of the global warming debate. Perhaps they should think again, as this article, recently published in the Royal Society's Phil Trans B, suggests that there is much truth in it.
CO2 enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more.
Plant breeders will probably be able to increase yields considerably in the CO2-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations.
You could almost get the impression that the biggest threat to the food supply is coming from government.
(H/T Roddy Campbell)
Reader Comments (54)
Nasif Nahle "You don't know to whom you're addressing your insults."
Oh yes we do, and you have a serious credibility issue that you need to address, as I will now show. I'm not sure that quoting yourself on the biocab.org website is really going to cut the mustard when we're looking for references, but since you do, let me remind you of what you say in your own work there:
http://biocab.org/Carbon_Dioxide_CO2.html#anchor_25
"CO2 densities have increased to more than 4000 ppmv in some geological eras, for example, during the Permian Period. When CO in the terrestrial atmosphere has reached densities this high in the past, life flourished abundantly [you presumably mean CO2 - I think 4000ppm of carbon monoxide would have wiped out animal life pretty effectively!!]. Consequently, we cannot consider such a high concentration of atmospheric CO2 as "pollution"."
[Readers please note that there are no known photosynthesizers using the C4 or CAM pathways in the Cambrian period, so all the plant life was using the C3 pathway which is highly inefficient at low CO2 levels]
and
"CO2 is the basic nutrient for plants and other photosynthetic organisms. Plants form the base of every food chain. Thus, the greater the density of CO2 in a given environment, the greater will be the production of food for plants and of the animals that feed on them."
But on August 19 you made two bizarre assertions in support of 'tom' against me, for which you have STILL not provided any references, viz
"CO2 enrichment up to 1000 ppm inhibits photosynthesis on C3 plants."
and
"concentrations above 550 ppm of CO2 makes the plant inhibits its production of stomata conducting to serious physiological problems for C3, C4 and CAM plants."
Well, you can't have it both ways, Nasif. Clearly, what you wrote on August 19 is totally contradictory to what you wrote on your website (which you are giving the link to!), as well as being unsupported in the literature. And you also mangled the quotations from Lodish and left out parts of the quotation from him that destroyed your case.
I think we all know now that what you wrote on August 19 was mischievous disinformation.
Gentlemen
I hope you are going to keep a lid on this argument.
ScientistforTruth says:
But on August 19 you made two bizarre assertions in support of 'tom' against me, for which you have STILL not provided any references, viz
This is ridiculous. I do never use to say anything against someone. You need to resort to ad hominem, as you're demonstrating it in all your posts. I don't because science is my job.
As for references about what I have been saying, read this PNAS report:
http://www.pnas.org/content/101/31/11506.full.pdf
To All... My work is honest and "ScienceForTruth" only seeks to deteriorate my credibility by cherrypicking those small mistyping errors, like the error when transcribed CO instead CO2. I don’t hide my name behind nicknames, in the first place. :)
Read all the articles I provided and find any “mischievous” concept or algorithm.