The ability of farmers to feed the world is being eroded by three different factors: meat, heat and biofuels. At least that’s according to Gwynne Dyer in an interesting piece entitled ‘How long can the world feed itself?’.
He may be right on meat and biofuels, but I don’t see ‘heat’ as a big a problem. Indeed its my understanding that as the world warms northern hemisphere farms will gain both the advantage of a longer growing seasons and a C02 fertilization effect. As regards Australia, well it might make sense for farmers to move north where there is more water. Indeed I think I would nominate ‘water’ rather than ‘heat’, as the third factor that may limit the ability of farmers to keep up with the growing world population.
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Thanks to Aaron Edmonds for sending in the link to Gwynne’s piece.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Glboal warming becomes a problem for farmers when it impacts on regional climate, messes with El Nino etc.
Farmers hone their activities to the particular regional climate they operate in. This even happens in Australia’s highly variable climate.
Global warming will impact on regional climate, and creates additional risk and uncertainty for farmers. Recent past climate records become less of a good indicator of what to expect in the future with global warming changing things rapidly.
The world has always had to cope with famine, global warming doesn’t change that, but it does add another risk factor.
This doesn’t sound right
“It takes between 11 and 17 calories of food (almost all grain) to produce one calorie of beef, pork or chicken,”
What about grass fed, as here in Australia?
Bjorn Lomborg showed that grain yields have not stopped rising.
This sounds like Club of Rome stuff to me.
I don’t know about ability, but there is definately a lack of willingness on behalf of many.
I stopped doing anything useful, once I discovered people would pay more for useless products.
Horses paid more than cattle, & advanced landscape plants earned much more than food, & could be sold when the market was right, not when the product was right.
Many of my friends grow less than 1/3 of what they used to. You can reduce your chance of losses that way, & surprise, surprise, you don’t make that much less.
Many of them have a genetic problem, & just can’t stop farming, but they do it with a much greater sense of self preservation than in the past.
They have no duty to feed the world.
When the world wants to pay a fair price for its food, I’m sure many can increase production.
I’m not one of them. I’ll never grow anything useful again, except fot home consumption. I can’t afford to.
Then there is http://www.ft.com/markets/commodities – link to the article “Grain Stockpiles at lowest for 25 years”. Sorry, I do not know how to post links. Sober reading.
“What Will Limit Food Supplies?”
um um um..the impositiion of imposing tariffs or taxes on food.
Isnt that right Ann Novek, you are aaginst restraints arent you?
Hmmm. Yields not increasing?
Well not in the USA
http://www.nass.usda.gov/Newsroom/2006/01_12_2006.asp
2005 Cotton Crop a Record Breaker, USDA Reports
Corn, Soybean Crops Second Largest on Record
WASHINGTON, Jan. 12, 2006 – U.S. farmers produced their largest-ever cotton crop and second-largest corn and soybean crops in 2005, according to the Crop Production 2005 Summary released today by the U.S. Department of Agriculture’s National Agricultural Statistics Service (NASS).
U.S. upland cotton production reached a record high for the second straight year. The 2005 crop of 23.1 million bales was 2 percent above last year’s 22.5-million-bale record. The 13.4 million acres harvested in 2005 topped last year’s acreage by 5 percent. Yields averaged 824 pounds per acre, down 19 pounds from the 2004 record.
Following last year’s record corn and soybean production, the 2005 crops were both the second largest in history. Corn produced for grain totaled 11.1 billion bushels, down 6 percent from 2004’s 11.8 billion bushels. Soybeans, meanwhile, came in at 3.09 billion bushels, 1 percent below last year’s 3.12-billion-bushel crop.
NASS estimates the 2005 average soybean yield at a record-high 43.3 bushels per acre, up 1.1 bushels from 2004. Yields increased dramatically across much of the northern U.S. growing area, reaching record highs in Iowa, Minnesota, Nebraska, New York and North Dakota. Louisiana soybean producers also saw record-breaking yields.
Corn yields were the second-highest on record, averaging 147.9 bushels per acre, down 12.5 bushels from 2004. Record-high yields were realized across the northern tier states, including Idaho, Michigan, Minnesota, Montana, New York, North Dakota, Washington and Wisconsin. Meanwhile, yields in the central and southern Corn Belt and southern Great Plains were down from last year’s record highs…
History has conclusively proven that what will limit food supplies is the efforts of anti-technology Luddites who want to put limits on progress.
In South Africa, the widespread adoption of genetically engineered white maize (corn) has increased productivity so much that the government has put the brakes on acreage devoted to its cultivation due to (gasp!) *overproduction* and a corresponding reduction in market price!
Elsewhere in Africa, efforts by Greenpeace and others have led to banning the crop, and malnutrition is rampant.
Another count in the indictment.
Wheat stockpile http://www.ft.com/cms/s/0c021878-5a16-11db-8f16-0000779e2340.html
“The USDA, which provides one of the most authoritative reports on global grain markets, said global wheat production would fall by 11m tons to 585.1m, causing global stockpiles to drop a further 7.1m from its previous forecast, to 119.3m. This represents a fall of 20 per cent from a year ago, putting stocks at their lowest level since 1981.
“The concern now is what happens next year. If we have poor conditions for growing wheat again, supplies could get very tight and we might see some demand rationing,” said Dan Cekander, grains analyst at Fimat.”
Thanyou Rog
You have provided the link to the article I referred to above. It maked sober reading. But to put it in balance, the probability that similar grain shortfalls will happen next year are possible, but unlikely. At least one of the major grain exporting nations are likely to have a good production season. However the trend for the last 25 years is declining reserves. We are seeing a series of peaks and troughs with the general trend downwards.
I am too close to the limitations (natural, and especially political) placed on the producers, upon whom much ultimately depends, to see the solutions.
Global crop yield growth static? Here’s data (graphs are given in the pdf file) that say no, cereal yield growth continues, and should continue in the future.
Yield growth rate slowing, well yes in some crops at least, and yes, technological innovation to accellerate that growth is being hampered by scaremongering, and widespread shortsighted opinion by rich, comfortable armchair theorists “we have plenty of food”.
http://www.ers.usda.gov/publications/arei/eib16/eib16_3-5.pdf
Area Growth Is Slowing, So Yields Will Become More Important
FAO reports that the total area devoted to crops worldwide has increased by about 0.3 percent per year since 1961, to 3.8 billion acres in 2002. Growth has slowed markedly in the past decade, to about 0.1 percent per year, as a result of weak grain prices, deliberate policy reforms (in North America and Europe), and institutional change (in the former Soviet Union). FAO estimates that an additional 6.7 billion acres currently in other uses are suitable for crop production, but this land is unevenly distributed, and includes land with relatively low yield potential and significant environmental value.
Given economic and environmental constraints on cropland expansion, the bulk of increased crop production will need to come from increased yields on existing cropland. FAO data indicate that world cereal yields rose by about 2.5 percent per year from 1961 to 1990, but growth slowed to 1.1
percent per year in the 1990s (fig. 3.5.3).
As a result of reduced input use (reflecting low cereal prices), market and infrastructure constraints, and low levels of investment in agricultural research and technology, IFPRI and FAO project that yield growth will slow further to about 0.8 percent per year over the next several decades (see Chapter 3.4, “Productivity and Output Growth in U.S. Agriculture”).
Genetic improvements have contributed greatly to gains in yields and production of major crops, beginning with wheat, rice, and maize in the 1960s. About half of all recent gains in crop yields are attributable to genetic improvements. By the 1990s, 90 percent of wheat acreage in developing countries was in scientifically bred varieties, as was 74 percent of land in rice and 62 percent of land in maize. In developed countries, 100 percent of land in wheat, maize, and rice was in scientifically bred varieties by the 1990s (and probably even earlier). Gains from genetic improvements will continue, but likely at slower rates and increasing costs, as gains in input responsiveness have already been largely exploited (see Chapter 3.1, “Crop Genetic Resources”).
Friends,
It’s time to consider some real-world dynamics. Net exporters of grain from developed countries are seeing a lot of global interference in markets from anti-globalists. (Skip the inherent contradiction.)
With the surge in oil prices we are seeing an increased interest in the Greenie dream: “renewable” energy from crops powered by the Sun.
Why bother fighting with export markets who screw things up with anti-globalist protectionism? Just grow it and burn it.
Greenies don’t want Africa to have GM crops, so we’ll just let the poor buggers starve and use the crops to power SUVs instead. What rot.
With the advent of biofuels, Greenpeace and others are on the same point of the sword they encountered with Golden Rice.
I.e., whom will you starve to prevent developing nations from using modern technology?
The rest of the world is about to turn surplus crops into the energy that fuels their comfort. And the rest of the world wants Africa to feed itself.
And the greenpeacers want Africa to do nothing, so that the income streams from televised appeals to “adopt a child in [African nation] for a dollar a day” will be preserved.
According to some estimates, about 80 percent of monetary aid to Africans never reaches them, and goes into the pockets of “civil society” (read, obese white people) instead.
Get the picture?
Follow the money. Africans don’t have very much of it.
Yes Schiller I am getting the picture. To end distortionary market pressures, you want…
* the US Farm Bill repealed
* billions in US agric subsidisies ended because it’s a huge distortionary interference in global markets
* an end to WTO special provisions for agricultural trade (supported by US) which disadvantage poorer country exports
* an end to expensive, tax-funded cotton subsidies in the US which artficially makes the US the largest exporter of cotton and benefits a small number of US cotton farmers and screws over a large number of more efficient African cotton producers
Good thinking. These moves to reduce American global market interference could help restructure the US economy so its exports are less commodity driven.
I would be happier if you included ROW Pinxi and you did not deliberately target the US; the EU is notorious for its selective trade policies and tariffs/subsidies.
Jen Marohasy says:
“Indeed its my understanding that as the world warms northern hemisphere farms will gain both the advantage of a longer growing seasons and a C02 fertilization effect.”
Have you any evidence to support your claim that farmers will gain from the CO2 fertilization effect. Are you aware of the research that demonstrates the downsides of increased atmospheric CO2 on plant growth?
yep me too again steve, it seems we have our BS detector on the exact same setting. I immediately thought ‘what a biased slant on CO2 fertilisation’ – for someone who likens themself to dead acclaimed philosophers and continually promotes evidence-based policy as though they have a monopoly on it, there’s some highly selective representation of the facts going on! Or we’ll all be eating cactus fruits.
Theres a lot around about CO2 effects of plant growth-eg
The fate of carbon in grasslands under carbon dioxide enrichment
BRUCE A. HUNGATE and others
Nature 388, 576 – 579 (07 August 1997);
The concentration of carbon dioxide (CO2) in the Earth’s atmosphere is rising rapidly, with the potential to alter many ecosystem processes. Elevated CO2 often stimulates photosynthesis, creating the possibility that the terrestrial biosphere will sequester carbon in response to rising atmospheric CO2 concentration, partly offsetting emissions from fossil-fuel combustion, cement manufacture, and deforestation,. However, the responses of intact ecosystems to elevated CO2 concentration, particularly the below-ground responses, are not well understood. Here we present an annual budget focusing on below-ground carbon cycling for two grassland ecosystems exposed to elevated CO2 concentrations. Three years of experimental CO2 doubling increased ecosystem carbon uptake, but greatly increased carbon partitioning to rapidly cycling carbon pools below ground. This provides an explanation for the imbalance observed in numerous CO2 experiments, where the carbon increment from increased photosynthesis is greater than the increments in ecosystem carbon stocks. The shift in ecosystem carbon partitioning suggests that elevated CO2 concentration causes a greater increase in carbon cycling than in carbon storage in grasslands.
Net Primary Production of a Forest Ecosystem with Experimental CO2 Enrichment
Evan H. DeLucia and others
Science 14 May 1999:
Vol. 284. no. 5417, pp. 1177 – 1179
The concentration of atmospheric carbon dioxide was increased by 200 microliters per liter in a forest plantation, where competition between organisms, resource limitations, and environmental stresses may modulate biotic responses. After 2 years the growth rate of the dominant pine trees increased by about 26 percent relative to trees under ambient conditions. Carbon dioxide enrichment also increased litterfall and fine-root increment. These changes increased the total net primary production by 25 percent. Such an increase in forest net primary production globally would fix about 50 percent of the anthropogenic carbon dioxide projected to be released into the atmosphere in the year 2050. The response of this young, rapidly growing forest to carbon dioxide may represent the upper limit for forest carbon sequestration.
Rising CO2 Levels and the Fecundity of Forest Trees
Shannon L. LaDeau,* James S. Clark
Science 6 April 2001:
Vol. 292. no. 5514, pp. 95 – 98
DOI: 10.1126/science.1057547
We determined the reproductive response of 19-year-old loblolly pine (Pinus taeda) to 4 years of carbon dioxide (CO2) enrichment (ambient concentration plus 200 microliters per liter) in an intact forest. After 3 years of CO2 fumigation, trees were twice as likely to be reproductively mature and produced three times as many cones and seeds as trees at ambient CO2 concentration. A disproportionate carbon allocation to reproduction under CO2 enrichment results in trees reaching maturity sooner and at a smaller size. This reproductive response to future increases in atmospheric CO2 concentration is expected to change loblolly dispersal and recruitment patte
New Phytologist
Volume 165 Page 351 – February 2005
doi:10.1111/j.1469-8137.2004.01224.x
Volume 165 Issue 2
Tansley review
What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2
Elizabeth A. Ainsworth1,2 and Stephen P. Long1
Free-air CO2 enrichment (FACE) experiments allow study of the effects of elevated [CO2] on plants and ecosystems grown under natural conditions without enclosure. Data from 120 primary, peer-reviewed articles describing physiology and production in the 12 large-scale FACE experiments (475–600 ppm) were collected and summarized using meta-analytic techniques. The results confirm some results from previous chamber experiments: light-saturated carbon uptake, diurnal C assimilation, growth and above-ground production increased, while specific leaf area and stomatal conductance decreased in elevated [CO2]. There were differences in FACE. Trees were more responsive than herbaceous species to elevated [CO2]. Grain crop yields increased far less than anticipated from prior enclosure studies. The broad direction of change in photosynthesis and production in elevated [CO2] may be similar in FACE and enclosure studies, but there are major quantitative differences: trees were more responsive than other functional types; C4 species showed little response; and the reduction in plant nitrogen was small and largely accounted for by decreased Rubisco. The results from this review may provide the most plausible estimates of how plants in their native environments and field-grown crops will respond to rising atmospheric [CO2]; but even with FACE there are limitations, which are also discussed.
REVIEW
Interactions between plant growth and soil nutrient cycling under elevated CO2: a meta-analysis
MARIE-ANNE de GRAAFF*†, KEES-JAN van GROENIGEN*†, JOHAN SIX*, BRUCE HUNGATE‡ and CHRIS van KESSEL*
New Phytologist (2004) doi: 10.1111/j.1469-8137.2004.01224.x
Global Change Biology Volume 12 Page 2077 – November 2006 Volume 12 Issue 11
Abstract
free air carbon dioxide enrichment (FACE) and open top chamber (OTC) studies are valuable tools for evaluating the impact of elevated atmospheric CO2 on nutrient cycling in terrestrial ecosystems. Using meta-analytic techniques, we summarized the results of 117 studies on plant biomass production, soil organic matter dynamics and biological N2 fixation in FACE and OTC experiments. The objective of the analysis was to determine whether elevated CO2 alters nutrient cycling between plants and soil and if so, what the implications are for soil carbon (C) sequestration. Elevated CO2 stimulated gross N immobilization by 22%, whereas gross and net N mineralization rates remained unaffected. In addition, the soil C : N ratio and microbial N contents increased under elevated CO2 by 3.8% and 5.8%, respectively. Microbial C contents and soil respiration increased by 7.1% and 17.7%, respectively. Despite the stimulation of microbial activity, soil C input still caused soil C contents to increase by 1.2% yr-1. Namely, elevated CO2 stimulated overall above- and belowground plant biomass by 21.5% and 28.3%, respectively, thereby outweighing the increase in CO2 respiration. In addition, when comparing experiments under both low and high N availability, soil C contents (+2.2% yr-1) and above- and belowground plant growth (+20.1% and+33.7%) only increased under elevated CO2 in experiments receiving the high N treatments. Under low N availability, above- and belowground plant growth increased by only 8.8% and 14.6%, and soil C contents did not increase. Nitrogen fixation was stimulated by elevated CO2 only when additional nutrients were supplied. These results suggest that the main driver of soil C sequestration is soil C input through plant growth, which is strongly controlled by nutrient availability. In unfertilized ecosystems, microbial N immobilization enhances acclimation of plant growth to elevated CO2 in the long-term. Therefore, increased soil C input and soil C sequestration under elevated CO2 can only be sustained in the long-term when additional nutrients are supplied.
Tree responses to rising CO2 in field experiments: implications for the future forest
R. J. NORBY, S. D. WULLSCHLEGER, C. A. GUNDERSON, D. W. JOHNSON & R. CEULEMANS
Plant, Cell & Environment
Volume 22 Page 683 – June 1999
doi:10.1046/j.1365-3040.1999.00391.x
Volume 22 Issue 6
The need to assess the role of forests in the global cycling of carbon and how that role will change as the atmospheric concentration of CO2 increases has spawned many experiments over a range of scales. Experiments using open-top chambers have been established at many sites to test whether the short-term responses of tree seedlings described in controlled environments would be sustained over several growing seasons under field conditions. Here we review the results of those experiments, using the framework of the interacting cycles of carbon, water and nutrients, because that is the framework of the ecosystem models that are being used to address the decades-long response of forests.
Our analysis suggests that most of what was learned in seedling studies was qualitatively correct. The evidence from field-grown trees suggests a continued and consistent stimulation of photosynthesis of about 60% for a 300 p.p.m. increase in [CO2], and there is little evidence of the long-term loss of sensitivity to CO2 that was suggested by earlier experiments with tree seedlings in pots. Despite the importance of respiration to a tree’s carbon budget, no strong scientific consensus has yet emerged concerning the potential direct or acclimation response of woody plant respiration to CO2 enrichment. The relative effect of CO2 on above-ground dry mass was highly variable and greater than that indicated by most syntheses of seedling studies. Effects of CO2 concentration on static measures of response are confounded with the acceleration of ontogeny observed in elevated CO2. The trees in these open-top chamber experiments were in an exponential growth phase, and the large growth responses to elevated CO2 resulted from the compound interest associated with an increasing leaf area. This effect cannot be expected to persist in a closed-canopy forest where growth potential is constrained by a steady-state leaf area index. A more robust and informative measure of tree growth in these experiments is the annual increment in wood mass per unit leaf area, which increased 27% in elevated CO2. There is no support for the conclusion from many studies of seedlings that root-to-shoot ratio is increased by elevated CO2; the production of fine roots may be enhanced, but it is not clear that this response would persist in a forest. Foliar nitrogen concentrations were lower in CO2-enriched trees, but to a lesser extent than was indicated in seedling studies and only when expressed on a leaf mass basis. The prediction that leaf litter C/N ratio would increase was not supported in field experiments. Also contrasting with seedling studies, there is little evidence from the field studies that stomatal conductance is consistently affected by CO2; however, this is a topic that demands more study.
Experiments with trees in open-top chambers under field conditions have provided data on longer-term, larger-scale responses of trees to elevated CO2 under field conditions, confirmed some of the conclusions from previous seedling studies, and challenged other conclusions. There remain important obstacles to using these experimental results to predict forest responses to rising CO2, but the studies are valuable nonetheless for guiding ecosystem model development and revealing the critical questions that must be addressed in new, larger-scale CO2 experiments.
Jennifer it is important to note that heat is very significant in reducing crop yields. Higher transpiration combined with lower rainfall has been the main contributor to the big drop in grain stocks this year in particular. A one degree temperature rise will reduce crop yields by roughly ten percent. Carbon fertilization leads to higher growth rates in plants but also leaves crops more susceptible to frost damage since growth is more succulent. More sunny growing days leads to more frosty nights. Higher temperature is nothing but bad for grain production.
Well in fact I believe that this entire scenraio is complete and utter nonsense! Get a life and stop bagging the environment! Who cares what’s it’s like 40 years from now, I’ll be dead, you will most likely be dead, so stop crying about it and live life like it was meant to be lived you boring old sods. I smoke, I use spray deoderant, I throw my rubbish wherever I fucking want to! Big deal bitch! I’m done caring!
Good riddance scumbags
Well in fact I believe that this entire scenraio is complete and utter nonsense! Get a life and stop bagging the environment! Who cares what’s it’s like 40 years from now, I’ll be dead, you will most likely be dead, so stop crying about it and live life like it was meant to be lived you boring old sods. I smoke, I use spray deoderant, I throw my rubbish wherever I fucking want to! Big deal bitch! I’m done caring!
Good riddance scumbags