Research Suggests Food-Crop Yields Under Future Greenhouse-Gas Conditions Will Be 50% Lower than Expected
30 June 2006
Five major food crops—maize, rice, sorghum, soybeans and wheat—grown in open-air trials under carbon-dioxide levels projected for the future are producing significantly less than those raised in earlier greenhouse and other enclosed test conditions. As a result, scientists are warning that global food supplies could be at risk without changes in production strategies.
The new findings are based on on-going open-air research at the University of Illinois at Urbana-Champaign and results gleaned from five other temperate-climate locations around the world.
According to the analysis, published in the 30 June issue of the journal Science, crop yields are running at about 50% below conclusions drawn previously from enclosed test conditions.
This casts serious doubt on projections that rising CO2 will fully offset losses due to climate change.
Results from the open-field experiments, using Free-Air Concentration Enrichment (FACE) technology “indicate a much smaller CO2 fertilization effect on yield than currently assumed for C3 crops, such as rice, wheat and soybeans, and possibly little or no stimulation for C4 crops that include maize and sorghum,”according to Stephen P. Long, U. of I. plant biologist and crop scientist.
FACE technology, such as the SoyFACE project at Illinois, allows researchers to grow crops in open-air fields, with elevated levels of carbon dioxide simulating the composition of the atmosphere projected for the year 2050. SoyFACE has added a unique element by introducing surface-level ozone, which also is rising. Ozone is toxic to plants. SoyFACE is the first facility in the world to test both the effects of future ozone and CO2 levels on crops in the open air. (Earlier post.)
Older, closed-condition studies occurred in greenhouses, controlled environmental chambers and transparent field chambers, in which carbon dioxide or ozone were easily retained and controlled.
By 2050 carbon dioxide levels may be about 1.5 times greater than the current 380 parts per million, while daytime ozone levels during the growing season could peak on average at 80 parts per billion (now 60 parts per billion).
Older studies, as reviewed by the Intergovernmental Panel on Climate Change, suggest that increased soil temperature and decreased soil moisture, which would reduce crop yields, likely will be offset in C3 crops by the fertilization effect of rising CO2, primarily because CO2 increases photosynthesis and decreases crop water use.
Although more than 340 independent chamber studies have been analyzed to project yields under rising CO2 levels, most plants grown in enclosures can differ greatly from those grown in farm fields, Long said. FACE has been the only technology that has tested effects in real-world situations, and, to date, for each crop tested yields have been “well below (about half) the value predicted from chambers,” the authors reported. The results encompassed grain yield, total biomass and effects on photosynthesis.
The FACE data came from experimental wheat and sorghum fields at Maricopa, Ariz.; grasslands at Eschikon, Switzerland; managed pasture at Bulls, New Zealand; rice at Shizukuishi, Japan; and soybean and corn crops at Illinois. In three key production measures, involving four crops, the authors wrote, just one of 12 factors scrutinized is not lower than chamber equivalents, Long said.
“The FACE experiments clearly show that much lower CO2 fertilization factors should be used in model projections of future yields,” the researchers said. They also called for research to examine simultaneous changes in CO2, O3, temperature and soil moisture.
While projections to 2050 may be too far out for commercial considerations, they added, “it must not be seen as too far in the future for public sector research and development, given the long lead times that may be needed to avoid global food shortage.”
Long and four colleagues were co-authors: Elizabeth A. Ainsworth, professor of plant biology; Andrew D.B. Leakey, research fellow in the Institute of Genomic Biology at Illinois; Donald R. Ort, professor of plant biology and crops sciences; and Josef Nösberger, professor at the Swiss Federal Institute of Science and Technology in Zurich. Long, Ainsworth and Ort also are affiliated with the Institute for Genomic Biology, and Ainsworth and Ort also are scientists in the USDA-ARS Photosynthesis Research Unit on the Illinois campus.
The Illinois Council for Food and Agricultural Research, Archer Daniels Midland Co., the USDA and U. of I. Experiment Station funded the research.
“Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations”; Stephen P. Long, Elizabeth A. Ainsworth, Andrew D. B. Leakey, Josef Nösberger, Donald R. Ort; Science 30 June 2006: Vol. 312. no. 5782, pp. 1918 - 1921; DOI: 10.1126/science.1114722
Throw in drought events, and the ever increasing chance of a Katrina type storm event, at the wrong point in the crops growing cycle, and you can see why growing our fuel over our food is a bad idea. Perhaps we will be able to drive anywhere we want, just not have anything to eat once we get there.
Posted by: Mark A | 30 June 2006 at 05:43 AM
On the heels the evidence of woody vines consuming forests comes this.
Now there's hard evidence to counter the "Carbon dioxide: we call it life" propaganda.
Posted by: Engineer-Poet | 30 June 2006 at 06:45 AM
There was a report on CNBC this morning that said that if all the ethanol facilities in process go to full production that there will be areas of the country with what is called a corn deficit. That's a bit murky, but the frustrating thing about food shortages as opposed to fuel shortages is that it is a bit more difficult to cut back on food than fuel (at least for many of us). It's not like we can increase our breaths per pound like we can increase our miles per gallon.
Some of us,including me, no doubt, could stand to eat a few less calories, but for the most part this seems like a cruel tradeoff.
More on topic, this report goes to show that global warming is life threatening and not just a matter of some inconvenience and discomfort here and there or a matter that only non human species are affected by.
Maybe those who have air conditioning can turn it up a bit but that doesn't seem relevant to crop production.
Posted by: t | 30 June 2006 at 06:50 AM
Isn't pro-life (of all kind) somewhat synonymous to reducing GHG. It seems that a highly polluted world may adversely affect all life forms. Some may and will adapt but others will have a difficult time to survive.
Cutting on essential food production to feed our gas guzzlers with cleaner alternative fuels may have a double beneficial effect for the first 10-20 years. Less GHG and less obesity = better health for most of us.
However, or OTOH (as Eng.-Poet would say), after 10+ years, the price of food may hit the roof and many of us may have already lost most of the accumulated body fat. Past that point, the food vs gas guzzler inner war will have to be addressed.
The end solution may be Electric Vehicles fed with Sun and Wind Energy and return the land to human and animal food production.
An interim solution may be PHEVs (for the 10 next years or so) but eventually EVs will be the best solution for most applications.
The current fossil liquid fuel distribution network and stations will be progressively replaced with Electrical Storage Units (batteries or ultra capacitors) recharge stations.
Most of the existing refineries will be replaced with clean electrical power generation plants to complement the new multiple Sun and Wind power units.
New Oil Refineries are NOT required. Minor upgrades to increase efficiency and reduce GHG are sufficient.
Posted by: Harvey D. | 30 June 2006 at 07:47 AM
A few points,
_Wouldn't the increased CO2 levels (per volume) at altitiude replicate the amount of the same gas (per cubic unit) at sea level in the past? Wouldn't this increase productivity of plants at altitiude in areas that get more favorable climate?
_On other side of the coin, perhaps the prices for the raw materials for processed foods become too expensive, making junk/fast foods either economically non-viable or just plain expensive. It would not be surprising for beef, and sweets to become semi-luxuries again.
_For other countries, especially those who import food and have a history of drought/crop failures, it would be more problematic. The Sahel, and many other savannas/ semi arid plains around the world face a long term repeated replication of dry decades. Wet years, that may make up for most/all of the deficits may follow, but may wash away large amounts of topsoil too. Add that to the unpredictable effects of aerosols and Global Dimming, and the wet Monsoons may go screwy. This may threaten Asia, and the 3+ billion that depend on it for at least part of their water. There is a possibility for food/water may become the new oil.
_As for fuel, algae oil/biomass is a way to provide it, but will require investments in the hundreds of billions of dollars. Solar electric (via cells, modified OTEC, or themal) will provide for peak power demand. Hydro current energy (tidal, river current, wave power on breakwaters, etc.), and biomass fired combined cycle, and nuke energy will provide for base loads, and cloudy/down days. Wind may augment supplies when available.
_Efficiency, and productivity gains are needed. Car pooling may one way. The point is to save energy, money, and time. If you do something useful (read, sleep, eat, work, etc) during your commute, it could give you some time that otherwise would be spent driving. For some, it could be a total of an hour a day, 188 hrs a year (4 person rotating car pool, 50 weeks a year). If you live farther out, it may be 3 hrs a day, 560+ hrs a year. It would be a chunk of time given back.
Posted by: allen zheng | 30 June 2006 at 08:51 AM
Harvey D: "Pro-life" is just a slogan meaning pro-reproduction. Pro-lifers are not opposed to the death penalty, bombing masses in Iraq or Isreal, or genocide.
I agree with you, we should be rapidly moving to electricity as the carrier for transportaion and power systems. There are plenty of renewable sources available now (just at a price).
Posted by: JM | 30 June 2006 at 09:23 AM
Wint be a problem for america as we will gm our crops into monster foods. Either that or we will make fake food or phood. Phood oh wonderous phood... I wonder if it will come in green?
Posted by: wintermane | 30 June 2006 at 10:21 AM
“Bombing masses in Iraq and Israel…”
N-a-a-a, they bombing themselves way more successfully.
Posted by: Andrey | 30 June 2006 at 10:26 AM
The july issue of Discover pg 28 describes an artificial tissue generation concept where meat can be produced without the use of animals. Put a few seed cells in a culture medium and overnight real bacon for breakfast is there. The technology is now used to grow skin for grafting of burn patients. I would guess it would be more energy efficient than passing proteins through farm animals because only those parts we actually eat would be grown.
Posted by: tom deplume | 30 June 2006 at 10:54 AM
Correct me if I'm mistaken, but most of the corn grown today goes to feeding cows to make beef. Eating corn yourself instead of eating cows would result in a huge energy saving.
Posted by: Dursun | 30 June 2006 at 11:11 AM
It's BS to suggest that the crops growing in 2050 will be the same as the ones we have today in 2006. 44 years of genetic engineering progress is going to put us into a totally different situation with regard to crop yields. Optimizing crops for higher CO2 levels or making other changes to improve productivity and robustness will be far easier than today.
Posted by: Hal | 30 June 2006 at 01:00 PM
Here is a story just today about genetic modification of plants to make possible nitrogen fixing by other than legumes. http://www.sciencedaily.com/releases/2006/06/060629122944.htm
This might not only increase yields, but cut the fosil fuel required to grow plants by 50% according to the article. That would be an extra bonus -- higher yields, lower cost, and less carbon in the air.
Posted by: JM | 30 June 2006 at 01:57 PM
Then why not use stuff like wood or algae for biofuels instead of foods like soybeans or corn?
Posted by: Mark R. W. Jr. | 30 June 2006 at 04:11 PM
Maybe we should reconsider growing crops outside to begin with. Hydroponics enable plants to be grown in a 200 story skyscraper if one was so inclined. Environmental control of the growing environment would greatly reduce risks of drought, disease, pest damage, etc. Hydroponics also seems to offer good control in the utilization of water, nutrients, light, etc. in the production process. I'm sure not all crop varietals are suited for hydroponics. Maybe produce crops/algae/etc. for biofuel in all the buildings left vacant by the dot com and telecom busts. This would reduce the need to operate ICE farm equipment across great land expanses, reducing GHG emissions, etc. I will be interested in the comments. Hopefully, logical and well informed ones.
Posted by: john galt | 30 June 2006 at 05:51 PM
Dursun: Eating vegetable/corn protein directly is up to 11 times more efficient than eating beef protein. However, we have to engineer corn to taste like beef.... and artificially add the other essential incredients.....odor..., look....etc....
Vegetarians do it without add-ons.
Posted by: Harvey D. | 30 June 2006 at 06:05 PM
Why hydroponics? Here in Vancouver huge greenhouses proved to be more competitive then open-air growth for many food crops. Longer vegetation period, mostly natural light, no herbicides and pesticides – soil is free of it, mold and fungi are controlled by specially cultivated ladybugs, and recently vegetables are more often chosen by their taste, not yield. And by the way, it is usual practice to burn NG and inject cooled exhaust into greenhouse to increase yield.
My personal favorite in genetic engineering is crossbreed of cow and lizard, with huge dinosaur-like tail. You step on it, and it broke out (and regenerates later) – all 100lb of New York steaks.
Posted by: Andrey | 30 June 2006 at 07:18 PM
No surprises here, biological growth rates are limited by the slowest process in a complex chain, not neccessarily the available inputs. Doubling CO2 does not imply a doubling of crop yields.
The only way to get more CO2 out of the atmosphere is to switch to crops that grow much faster, e.g. elephant grass or algae. These would replace traditional building materials and fossil fuels.
Another option would be to use renewable power and sea water to sequester CO2 in the form of CaCO3 (limestone). The resulting structures are more efficient at encouraging new ecosystems than traditional approaches. However, a way would have to be found to sharply reduce the cost of the electrodes, e.g. by wrapping wires around frames of elephant grass stalks cut lengthwise.
Posted by: Rafael Seidl | 30 June 2006 at 07:46 PM
Actauly beef and more so pork and chicken were and still are simply ways to convert foods we cant actauly eat directly into much more valuable foods we can. Most of the feed given to cattle would kill a human. Most times its tainted by mold or rot or just tastes horrid. Many other times its whats left over after they extract valued oils and starches and other things and simply would make you puke if you ate it.
After that its excess corn and other foods that didnt sell and stayed stored beyond safe durations.
Posted by: wintermane | 01 July 2006 at 12:14 PM
It's unclear how much of the reduction in yield was due to the ground level ozone. IIUC most ground level ozone results from NOx & incomplete combustion products in combustion engines. This would be much easier to reduce than CO2 emmissions & the levels of O3 will drop much faster after the pollutions is stopped than CO2 levels will drop if we stop burning fossil fuels.
Posted by: Jim Baerg | 02 July 2006 at 09:17 AM
Not to mention that most smog and most farms arnt in the same spots;/
Posted by: wintermane | 02 July 2006 at 07:18 PM
The reason big oil gets subsidies has nothing to do with the gop it has everything to do with pork barrel projects. Every senetor and congress critter wants to score political points by bringing jobs and money to thier state. They get this by spending our money to make it look like they actauly did something by influencing where big oil builds new plants and instelations and hires more people.
In reality big oil would be building plants and hiring people no matter what.. but money does effect where they build first and so the congress critters can get talking points...
To stop the crsp you need to take the money away from the asshats. But then who do we trust with the power of the nations wallet?
Posted by: wintermane | 03 July 2006 at 10:39 AM