Sometimes I wonder if science hasn’t been infected with some sort of mass delusion about CO2. Watch this amazing video on CO2 and plant growth from CO2Science.org, then read below the claims made in this UC Davis press release.
Rising CO2 levels threaten crops and food quality
Rising levels of atmospheric carbon dioxide interfere with plants’ ability to convert nitrate into protein and could threaten food quality, according to a new study by researchers at the University of California, Davis.
The scientists suggest that, as global climate change intensifies, it will be critical for farmers to carefully manage nitrogen fertilization in order to prevent losses in crop productivity and quality.
The study, which examined the impact of increased carbon dioxide levels on wheat and the mustard plant Arabidopsis, will be published in the May 14 issue of the journal Science.
“Our findings suggest that scientists cannot examine the response of crops to global climate change simply in terms of rising carbon dioxide levels or higher temperatures,” said lead author Arnold Bloom, a professor in UC Davis’ Department of Plant Sciences.
“Instead, we must consider shifts in plant nitrogen use that will alter food quality and even pest control, as lower protein levels in plants will force both people and pests to consume more plant material to meet their nutritional requirements,” Bloom said.
Climate change, CO2 and agriculture
Historical records have documented that the concentration of carbon dioxide in Earth’s atmosphere has increased by 39 percent since 1800. If current projections hold true, the concentration will increase by an additional 40 to 140 percent by the end of the century.
This trend is of concern to agriculture because elevated atmospheric carbon dioxide levels have been shown to decrease the rates of photorespiration, the naturally occurring chemical process that combines oxygen with carbohydrates in plants.
At first, this reduction in photorespiration boosts photosynthesis, the complementary process by which plants grow by using sunlight to turn water and carbohydrates into chemical energy in the form of plant sugars. In time, however, the increase in the rate of photosynthesis tapers off as the plants adjust to increased atmospheric carbon dioxide, and plant growth slows.
The nitrogen connection
Nitrogen is the mineral element that plants and other living organisms require in the greatest quantity to survive and grow. Plants obtain most of their nitrogen from the soil and, in the moderate climates of the United States, absorb most of it through their roots in the form of nitrate. In plant tissues, those compounds are assimilated into organic nitrogen compounds, which have a major influence on the plant’s growth and productivity.
Earlier research has shown that when atmospheric carbon dioxide concentrations increase by 50 percent, the nitrogen status of plants declines significantly.
More specifically, findings from previous research by Bloom and colleagues suggested that elevated levels of carbon dioxide decreased photorespiration and inhibited nitrate assimilation in plant shoots.
New UC Davis study
In their most recent study, Bloom’s team examined the influence of elevated carbon dioxide levels and, in some cases, low atmospheric oxygen concentrations, on nitrate assimilation in wheat and Arabidopsis plants using five different methods.
Data from all five methods confirm that elevated levels of carbon dioxide inhibit nitrate assimilation in wheat and Arabidopsis plants. The researchers note that this effect could explain why earlier studies by other researchers have documented a 7.4-percent to 11-percent decrease in wheat grain protein and a 20-percent decrease in total Arabidopsis protein under elevated carbon dioxide levels.
“This indicates that as atmospheric carbon dioxide concentrations rise and nitrate assimilation in plant tissues diminishes, crops will become depleted in organic nitrogen compounds, including protein, and food quality will suffer,” Bloom said. “Increasing nitrogen fertilization might compensate for slower nitrate assimilation rates, but this might not be economically or environmentally feasible.”
He noted that farmers might be able to increase their use of nitrogen-rich ammonium fertilizers to ease the bottleneck of nitrate assimilation in crops but would have to carefully manage fertilizer applications to avoid toxic accumulations of ammonium in the plants.
To develop solutions for dealing with the impact of major increases in atmospheric carbon dioxide levels on crops, further research is needed on how plants assimilate nitrate and ammonium, Bloom said.
Working with Bloom on this study were Martin Burger of UC Davis’ Department of Land, Air and Water Resource; Jose Salvador Rubio Asensio of UC Davis’ Department of Plant Sciences; and Asaph B. Cousins, currently of the School of Biological Sciences at Washington State University.
Funding for this study was provided by the National Science Foundation, the U.S. Department of Agriculture and Spain’s Agencia Regional de Ciencia y Tecnologia.
About UC Davis
For more than 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has 32,000 students, an annual research budget that exceeds $600 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges — Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science. It also houses six professional schools — Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.
Media contact(s):
- Arnold Bloom, Plant Sciences, (530) 752-1743, ajbloom@ucdavis.edu (He is away from campus until Wednesday but can be reached by e-mail.)
- Pat Bailey, UC Davis News Service, (530) 752-9843, pjbailey@ucdavis.edu
The good hoax ship is running in circles yelling anything, try anything, we’re going down.
So
If it’s a 7-20% decrease in protein, but a 40-50% increase in mass, that’s a net gain.
As I recall from my farming days, which was a long time ago, in a distant……ooops. Wrong story.
Protein in wheat is usually about 15%. High values are about 20%. A 20% reduction would reduce protein to about 12% to 16%. Carbohydrate and fiber content would see a corresponding increase.
Also, as I recall, high protein content is a function of a dry period during seed development. Did these researchers control for moisture variations in protein development?
now, I need to go finish cleaning the ‘droids.
So CO2 causes more rapid plant growth and you therefore need more NPK… what’s the big deal?
Enneagram says:
May 14, 2010 at 5:59 am
“CO2 follows temperature, not the other way. Open a coke and you´ll see it: The more you have it in your warm hand the more gas will go out when you open it.”
Coke is super-saturated. Shake it and you’ll see.
Higher temps can drive CO2 out of the oceans. Higher CO2 levels can cause higher temps. It is a feedback cycle that can be started from either side. This time we are the cause of higher CO2 levels. While the higher temps that are coming are not new, the rate of change is faster than what occurs in natural cycles.
Glad some commenters mentioned that higher CO2 level results in plants using water much more efficiently. Adequate supplies of fresh water for irrigation and sanitation is a large and growing problem. Increased atmospheric CO2 concentration will go a long way towards ameliorating that particular problem. Supply of nitrogen fertilizers are not a problem. Phosphorous fertilizer is a major problem about to happen. There are only two major sources of phosphorous fertilizer in the world and their capacity to produce is reaching its limit. Excess phosphorous in runoff and wastewater is already a problem. Waste water treatment plants are scrambling for efficient ways to capture the excess phosphorous both to keep it away from where it doesn’t belong (lakes, rivers, and oceans which is the usual end-point for treated water) and to reduce the demand on the primary phosphorous mines.
Wheat is actually not a great source of nutrition for human beings. All kinds of health problems occur from gluten intake. It’s long been known that some people are so gluten intolerant it will kill them but it’s just been discovered recently that people who aren’t so gluten-sensitive also have problems from it. Rice, corn, and soybeans are gluten-free and generally much better for you. Soybeans are very high in protein content and they also take nitrogen from the air and fix it into the soil with the aid of symbiotic bacteria on their roots. More and better crop rotation with soybeans on wheat fields should be high on the list of things to do for a lot of good reasons.
This possibly isn’t as controversial (or important) as is being claimed. Photosynthesis happens because of an enzyme called rubisco – enzymes are proteins and hence need nitrogen to be synthesised. An increased CO2 level would allow more photosynthesis for the same amount of rubisco, so more plant ‘bulk’ for the same amount of ‘nitrogen’. Or am I missing something? Plants aren’t built of muscle like us, it’s stuff like cellulose and lignin which contains no protein (nitrogen)
Not all crops fix their own nitrogen either (or rather, have symbiotic bacteria to do it for them) so be careful on that point too.
The problem is not CO2 but who owns LAND in practice, if the farmers then it is OK, if the BANKS then we are back to Monarchy times, call it PLUTOCRATIC times if you wish, the ARISTOCRACY of a very small world banking elite.
Back in the 18th century land was owned by the land-lords, these were independent from the banks. Peasant were supposed to be slaves, though they could know, even be friends of their landlords. Revolutions changed this, democratizing property, but, as the wheel turned around through banks and through the Genetically Modified Seeds, which are STERILE (farmers can not obtain their own seeds), land is really owned by the very few worlwide land lords. You were free, now you became employees, clerks, servants, not even free peasants.
wheat and Arabidopsis plants. (mustard)
That is code for trouble.
In-N-Out has a reputation to live up too and do they ever. Now when you order a burger, their reputation will be damaged because the mustard and the bun have .013 grams less protein.
I was under the mistaken impression the protein was in the meat.
Henry chance says:
We have good news and we have bad news. The crop yield is up 100% per acre. The protein yeild of the wheat per acre is up only 85%.
Send us money.
==================
“You give us the money,
We’ll give you the honey.
And conversely:
No money: no honey.
Cause we’re professionals, honey.”
From my admittedly passing experience with making bread in a bread machine, wheat flour with a protein level of at least 13%, preferably nearer 14% is needed, especially if you are going to make wholemeal bread where the bran flakes tend to have a negative effect on how well the dough rises. I also understand that much of the wheat we grow in the UK is not suitable for bread making, having a low protein content and being more suitable for cakes. Some food scientists here might correct me on this though.
It does seem possible that in wheat, faster and more growth might have trade offs…there usually are trade offs with food. The Iceberg lettuce is a classic of this effect, crisp, very good keeping qualities, tasteless and awful to eat.
Chris says:
May 14, 2010 at 2:34 am
and next they will show, that water and fresh air are pollutants…
————-
humm…they already have. The reduction in tailpipe and stack pollutants has reduced their cooling effect, increasing the rate of warming.
So…air pollution control devices are enhancing AGW.
Clean air is a “bad” thing.
Mike says:May 14, 2010 at 7:26 am
There are many papers out there pointing in various directions. It is foolish to assume only the ones with results you like are the only relevant ones. We are changing the composition of our atmosphere. We are changing the chemistry in our oceans. We are changing our climate. Some of these changes may be positive, but one would have to be hopelessly naïve to assume all is benign.
As a physiologist, I have not read one paper where the net effect of increased [CO2] is negative to crop yield.
Period.
Show me otherwise or quit trolling.
Oh, and to be fair I should mention that the video is not very compelling. Those plants were obviously grown under reduced light and are etiolated. Not representative of actual growing conditions.
The video, interesting as it is, didn’t make it clear what the yield was. How, for example, might that translate to wheat, rice, and corn? What too of the efficiency of the pollinators, pests, weeds, water consumption?
Am I really ready for a 3′ stalk of asparagus?
I would think too that farmers might need to consider equipment changes. The machinery of farming are designed for current crop characteristics. That may all change.
Those curiosities aside, I find it absurd that anyone would consider CO2 a poisonous gas to be regulated like cyanide. I can see the warning labels now: Warning! This softdrink contains gasses known to destroy planets.
oldseadog says:
May 14, 2010 at 12:20 am
‘How does this fit with the tomato growers in the Netherlands who put added CO2, up to 1500ppm I have read, into the greenhouses and get better yields?’
Ah yes, but those are rotten tomatoes.
Once again UC Davis shows us why they are a second or third tier University.
Any child from 2 generations back knows that CO2 in vastly increased concentrations results in vast increase in crop yields.
UCD simplistic review of 2 crops for nitrogen is sophomoric at best and belongs in a middle-school science fair.
Any decent crop scientists knows that Food crops nutrition value is determined by ALL of the minerals in the growing medium. This is why “bottom land’ is preferred for crops and why decent farmers enrich the soil with more than NPK.
We all know CO2 is not the primary mover of ‘climate change’, its much more complex than this – but there are many sophomoric climate scientists trying to prove they know more than anyone else.
‘Science’ deserves to be peer reviewed by actual peers, and the results published by independent sources.
Thanke Mike McMillan for your graph of Illinois corn yields, but most importantly, the information that there have been quite large swings in atmospheric CO2 concentration in the last 200 years. I was aware that there was a seasonal variation in CO2 levels, but it had never occurred to me that CO2 concentration in 1940 was 391.5 ppm. The graph you posted isn’t clear so I did a fast search for CO2 concentrations predating Mana Loa (anything before 1958) and was surprised by the result.
http://www.biomind.de/realCO2/literature/evidence-var-corrRSCb.pdf
is a paper that analyzes variability of CO2 concentration during the 20th century. The chemical means of analysis used prior to spectroscopic methods are very accurate with precision better than 1% (or even better in the hands of some people). What the data show is that in the 1940’s CO2 concentrations went up and the most interesting value is the 454.7 ppm CO2 measured in Antarctica in 1941. Averaging multiple sources gives about 410 ppm in the mid 1940’s
I just found this out today and these measurements would seem to invalidate AGW as we seemed to get through the 1940’s just fine with those “dangerous” atmospheric CO2 concentrations. I wasn’t born then, but I don’t recall my parents telling me about the rise in sealevels that flooded coastal areas, the spread of malaria in northern Europe, the disappearance of the polar bears and extinction of sea life because of falling ocean pH.
The data on CO2 concentration over the last 180 years tell me that we really haven’t a clue about what controls atmospheric CO2. Having worked in organic chemistry/biochemistry at one stage in my career I’m well acquainted with chemical methods of measuring trace gasses and believe the values that these scientists got. The only concern I would have is if some of the readings are skewed by the presence of a “CO2 island” effect as one would expect CO2 levels in an urban environment to be greater than in a rural environment. When multiple studies show a correlated rise in CO2 concentrations in the 1940’s then there was something very interesting happening at that time and I’m curious if the IPCC was aware of this research.
Mike says:
May 14, 2010 at 7:26 am
“There are many papers out there pointing in various directions. It is foolish to assume only the ones with results you like are the only relevant ones. “
This is the heart of the matter, isn’t it? When a true scientist sees contradicting studies he looks for a way to disprove both. When a political scientist sees them he picks the one that supports his own “settled” view.
Sid F says:May 14, 2010 at 8:04 am
I also understand that much of the wheat we grow in the UK is not suitable for bread making, having a low protein content and being more suitable for cakes.
Then let them eat cake.
As a note, you have to get up above 5% CO2 in the atmosphere for humans to be affected. Above that, you can get some minor symptoms like headaches up to 10%. am not sure what happens after 10%, but I would suppose your CO2-O2 exchange in your lungs might get a bit screwed. Sorry short stuff, I won’tmake you grow.
Here is a link to the study http://www.sciencemag.org/cgi/content/full/328/5980/899
It is a seedling study, the plants are not grown to maturity. In fact, they are grown for only a few days. It is a jump to assume that grain quality or quantity will suffer based on this study. Also, low light intensity maybe a reason for lower NO3 assimilation under higher CO2. You need the photons for the process to work properly.
Climate science has been infected with government money. All government money is poisoned by the political agenda of the power-hungry aristocrats who run the government. Since the great global warming fraud is a wonderful excuse for governments to seize power, they fund the frauds like crazy and don’t fund honest science. If you want honest science, you have to get rid of the government money.
Merovign says:
May 14, 2010 at 2:12 am
//i.e. did CO2 inhibit absorption of nitrogen or did growth outstrip the availability of nitrogen?//
Of course it outstripped. Every gardener knows that when plants are dormant, you don’t fertilize them – they can’t use it. If plants in the summer are growing rapidly, of course you need to fertilize them more, not just with N but with P and K. Duh! (to UC Davis “scientists”)
Rutgers AG School, one of the best, established this with many plants half a century ago, especially their famous Rutgers tomatoes and other wonderful pant hybrids. They established growing optima that INCLUDED raising CO2 three fold while providing optimal nutrients. Its almost like ground hog day with these UC simpleton scientists. What poor non-scientists these are. A farmer has way more knowledge & know-how.
This is like saying that raising water intake for a human being, but not feeding him anything will cause death. That means it was the extra water that killed him! OR, a better conclusion for the eco-simpletons, is that parts per quadrillion of dioxin, present in the water, did it! Adjust the experiment and control the conclusion!
If they grew these things hydroponically, and did not add anything to the water, like lime, to buffer the slightly decreased pH, this could have reduced protein levels in the seeds, also. Point: these experiments could easily be “adjusted” for any outcome one chooses.
The dinosaurs seemed to have had adequate protein intake from the fact that they grew to astonishing sizes because the plants grew so unbelievably fast! Because CO2 was in 10 parts PER THOUSAND (10,000 ppm).
All this is giving me a headache! Where’s my duct tape?