From the University of Minnesota:
When it comes to variations in crop yield, climate has a big say
Discovery of the huge but varied role of climate change in food production provides valuable insights for preparing for future conditions
Credit
University of Minnesota Institute on the Environment
What impact will future climate change have on food supply? That depends in part on the extent to which variations in crop yield are attributable to variations in climate. A new report from researchers at the University of Minnesota Institute on the Environment has found that climate variability historically accounts for one-third of yield variability for maize, rice, wheat and soybeans worldwide — the equivalent of 36 million metric tons of food each year. This provides valuable information planners and policy makers can use to target efforts to stabilize farmer income and food supply and so boost food security in a warming world.
- The work was published today in the journal Nature Communications by Deepak Ray, James Gerber, Graham MacDonald and Paul West of IonE’s Global Landscapes Initiative.
- The researchers looked at newly available production statistics for maize, rice, wheat and soybean from 13,500 political units around the world between 1979 and 2008, along with precipitation and temperature data. The team used these data to calculate year-to-year fluctuations and estimate how much of the yield variability could be attributed to climate variability.
- About 32 to 39 percent of year-to-year variability for the four crops could be explained by climate variability. This is substantial — the equivalent of 22 million metric tons of maize, 3 million metric tons of rice, 9 million metric tons of wheat, and 2 million metric tons of soybeans per year.
- The links between climate and yield variability differed among regions. Climate variability explained much of yield variability in some of the most productive regions, but far less in low-yielding regions. “This means that really productive areas contribute to food security by having a bumper crop when the weather is favorable but can be hit really hard when the weather is bad and contribute disproportionately to global food insecurity,” says Ray. “At the other end of the spectrum, low-yielding regions seem to be more resilient to bad-weather years but don’t see big gains when the weather is ideal.” Some regions, such as in parts of Asia and Africa, showed little correlation between climate variability and yield variability.
- More than 60 percent of the yield variability can be explained by climate variability in regions that are important producers of major crops, including the Midwestern U.S., the North China Plains, western Europe and Japan.
- Depicted as global maps, the results show where and how much climate variability explains yield variability.
The research team is now looking at historical records to see whether the variability attributable to climate has changed over time — and if so, what aspects of climate are most pertinent.
“Yield variability can be a big problem from both economic and food supply standpoints,” Ray said. “The results of this study and our follow-up work can be used to improve food system stability around the world by identifying hot spots of food insecurity today as well as those likely to be exacerbated by climate change in the future.”
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I think the authors of the study are kerfluxing climate and weather. The climate has not changed nearly enough nor often enough to be blamed for anything. On the other hand farming technology, hybridization, irrigation, and other related factors change and improve frequently and not always for the better, and changes in technology can easily mask effects of weather. Moreover, farming has moved en mass to marginal areas where cheap energy, good will, and tax dollars permit it but where weather, soil, and labor-intensive technology discourages long term success. What comes to mind is Canadian wheat and trying to grow anything in arid Africa. I would bet that more food acreage is lost to biofuel policies than is lost to weather variability.
Another factor is politics and meddling in agriculture. Here in our region we watched acres and acres of apple trees drop fruit and then the felling of the trees as orchardists gave up trying to make a living. I can easily see in my lifetime, and I’m old, when labor costs are so high that apples will have to be imported like cheap plastic products from Asia – exactly what happened to cane sugar and pineapples from Hawaii.
I disagree, I think they read “grant money” with excellent accuracy, comprehension and perspicacity.
if I remember correctly the Hawaiian sugar issue was due to Reagan’s policy trying to promote use of high fructose corn syrup to benefit the corn growers, by instituting/raising the tax on sugar. It is/was political meddling as you mentioned. As with most if not all government policies the secondary affects are rarely considered and if they are considered they are routinely discounted as being insignificant.
Cheers!
Joe
such as diabetes and morbid obesity
In the Horn of Africa, Ethiopia etc, crop yields are nothing to do with climate change and everything to do with changes in farming practices since the 1980’s famine!
Curiously the Chart shows ‘Climate Change’ as having no effect on production in Australia! Agricultural production in Australia has always had wide swings caused by variations in the weather. This omission throws the rest of the Chart into severe question and suggests that it has just been ‘made up’.
No change is grey; white means not grown there (in significant amounts). We do grow maize, but only in tiny amounts compared to wheat.
The open access paper and SI do show major swings for Australian wheat.
And the paper didn’t try to cover PompousGit’s amazing potato yield. Man, good underlying growing conditions. More of northern Wisconsin is getting into fancy potatoes, converting from vegetables in ‘the sand hill country’ that produces lots of US frozen veggies. Comparative potato yields are pathetic, but then they are only the high priced fancies.
We are mainly maize, soy, oats (alfalfa first year cover crop) and alfalfa on my SW Wisconsin biggish ( barely top 25% in the state) dairy farm. Sometimes some winter wheat depending on the fall harvest timing. Sell excess maize to ethanol distillers, get back distillers grain to reduce the alfalfa/ chopped green corn component of dairy feed. Allows a changed cropping rotation on the contours. About 1.8 to 2 million pounds of Class A milk/year the main product, lots of veal/steers since only females milk (and because of the US beef situation given semidrought elsewhere, we presently get $400/ head for a week old steer! Minting money, since used to be $25. So you know that won’t last—just weather and farmers), some beef the minor. Hamburger is what happens to dairy cows after a few freshenings when their milk production drops. And, PG, cowbarn manure makes great nitrogen/phosporus fertilizer. We produce lots for free…except for the expensive manure spreaders. Only supplement K. But apparently you don’t need any, and we could not afford to ship it to you anyway. Regards.
Based on some trials I had a hand in some 20+ years ago, we could do better than that. Artificials applied at about half the recommended rate plus the organic fertilisers I use (compost, aged animal manures and regular foliar applications of fish & seaweed emulsion) and, critically, sub-surface irrigation at a carefully controlled rate. A farmer I know managed 120 tonnes/Ha on his first go.
What the armchair pundits don’t realise is it’s the yield at the bank that counts. Maximising yield per hectare is never going to be good for the bank balance. Maximising yield per man-hour makes more sense, but then it too fails to take into account many other important factors. But then you already know that as a farmer.
Yes, FYM is invaluable stuff and happily Australian farmers are rediscovering it.
Sounds like you are creaming it with the beef 🙂 Congrats.
You’re correct we don’t need, or could afford to purchase your manure. Interesting you need K supplement. When I first purchased the farm, K was ca. 40 ppm so I applied some muriate of potash. Three years later it had reached 268 ppm, way higher than what I had applied. Organic matter had gone from 8% to 14 % and CEC from 8.86 to 20.14. Available P from 89 ppm to 463 ppm.
reality check on the loss due to “climate variability” -36 million tonnes vs 2.3 BILLION tonnes
http://www.unep.org/wed/2013/quickfacts/
•The amount of food lost or wasted every year is equivalent to more than half of the world’s annual cereals crop (2.3 billion tonnes in 2009/2010).
Perhaps it would be more clear if I stated it as 36 million tonnes vs.HALF of 2.3 BILLION tonnes.
The problem is, when you dig into the UNEP and FAO country level data, it just is not true in any literal sense. Certainly not true for all the major big four staple grain producers like US, Canada, Brazil (soy), Argentina, Russia , Ukraine (wheat), China (rice, maize–and guess who is the number 1 producer of potatoes in the world? Some hints. Ain’t the US. Russia is #3, India is #2), Australia…
Maybe its that ‘equivalent to’ thingy given an 1:4 caloric conversion to meat protein from maize and soya, so this is really a UNEP vegan plea…? Makes more sense that way. Good researching spot, but just shows more UN duplicity.
In my calculation above I just looked at the crops they specified, wheat, rice, corn and soybean. I still think the correct comparison is 36 million tonnes versus 2,400 million tonnes of those crops produced. Anyway, the proportion affected is not very big.
From the University of Minnesota:
When it comes to variations in crop yield, climate has a big say
Discovery of the huge but varied role of climate change in food production provides valuable insights for preparing for future conditions
Maybe they should just stick to cheese?
michael
No, No, No.
Wisconsin does cheese. Proof, Green Bay Packers cheesehead fans.
Minnesota does hogs. Proof, Hormel (Spam) headquarters.
Although Iowa is giving Minnesota a run for their money concerning ‘hog heaven’. Proof, new US senator Joni Ernst.
With apologies to North Carolina concerning hogs but NOT cheese.
@The Pompous Git January 22, 2015 at 11:29 am
…I’ve said this many times here: “The single biggest factor in crop yield is water”. Specifically, insufficient water reduces yields. It’s why humans now sequester ~50% of rainfall…
Really? Do you have a cite for that? Even counting all the dams in all the world, and all the aquifers as sequestered rather than natural, half of all our rainfall sounds rather a lot to me…
Sounds high to me, too. Cite?
Comes from a slide presentation linked to by Roger Pielke Sr several years ago. Since the PPS wasn’t located on Pielke’s website, searching there requires me to remember the context. Aaargh!
Why is the Internet so slow today? 12 Mb/s my arse!
Sarah Postel has a paper saying 54%, but the execrable Ehrlich is a co-author. See: Human appropriation of renewable fresh water 1996. http://www.sciencemag.org/content/271/5250/785.short
It would appear that 11-13 % is sequestered behind large dams (http://www.giss.nasa.gov/research/briefs/gornitz_06/)
but that doesn’t include rainfall that is sequestered in small and medium sized dams, general agricultural produce, and forestry. We are also using fossil water (underground aquifers) faster than replacement. Obviously ~50% didn’t appear outrageous to Pielke Sr, and it doesn’t to me. But then I’m a farmer who sequesters his local rainfall.
I intended to write: “But then I’m a farmer who sequesters most of his local rainfall.” Most of it grows grass for cattle. Run-off only occurs during heavy rainfall, and wintertime when pasture has low water needs.
The best I can do for water use estimates involves back of the envelope calculations from figures in the wiki, so nothing below is reliable. But my estimates are:
Of total world annual water use, 70% goes to agriculture. This is given as approx. 2 x 10 to the 9 cubic meters. Which suggests that total world annual water use is approx. 3×10 to the 9 cu.m.
Total world annual rainfall is 5×10 to the 14 cu.m. Assuming we sequester ALL the water we use, we sequester approx.1/500,000 of total rainfall.
Unless someone who knows better can correct me?
DG, your surface water ag use numbers are roughly right. But you missed some very important things hidden in the UN water data background. For serious referenced details, see the water chapter of ebook Gaia’s Limits. Too convoluted (and ‘shocking’ concerning yet more UN deception) to explain in a brief post here. Regards.
But does not the IPCC say that until 2060 at least — using their greatly highballed projections — there will be what they quaintly call “net beneft” for both man and beast?
The biggest threats for food production from an historical perspective isn’t climate.
1. Centralist experiments like the USSR under Stalin triggering the biggest famine of our modern history killing 20 million Russians
2. Centralist mandates transforming 40% of the maize crops in Europe and the USA into bio ethanol.
3. Lying Green Activists delivering fraudulent reports resulting in the ban of pesticides (dying of bees)
4. Big money and political zealots blowing up the financial system using Government debt bonds to back derivatives trading.
5. Sanctions and war
Yes, political man and financial man teaming up with green zealots, the worst enemies of human kind.
I see what they did there.
This was published so that ” …information planners and policy makers can use to target efforts to stabilize farmer income and food supply and so boost food security in a warming world.” Evidently to introduce the two words “warming world” that draw funding. They only looked at variations within fairly normal range. Actually things are much worse than that. During the Little Ice Age millions died because of crop failures due to climate change.
Things were far worse in earlier climate reversals such as the Vandal Minimum. Historians refer to The European Miracle…
Then there’s crop spoilage. Rye grown in cold wet times can play host to ergot, a nasty fungus. That spoilage can waste a big proportion of the crop. Ergotism is … unpleasant.
OTOH lysergic acid is extracted from ergot to the great delight of hippies worldwide 😉
LOL!! Wow…. So these brilliant researches found that when the weather is good, crop yields are good….. and… when the weather is bad, crop yields are bad….. Who knew?
In the US, crop yields have increased a whopping 80% just since the 1980’s… Obviously a lot of this increase is due to advances in: farm machinery, high-yield seed development, fertilizers, irrigation, insecticides, herbicides, etc., but increased CO2’s fertilization has also contributed to the rapid increase in global crop yields:
http://data.worldbank.org/indicator/AG.YLD.CREL.KG
IPCC’s AR5 report also admits that global severe weather frequency and intensity have been flat for the past 50~100 years so what the heck are these researches trying to prove?:
http://wattsupwiththat.com/2013/10/03/pielke-jr-agrees-extreme-weather-to-climate-connection-is-a-dead-issue/
Why the heck is CAGW still taken seriously? Why is taxpayer money still being thrown down rabbit hole for these inane and worthless “research” papers that vainly try to contrive support for the disconfirmed CAGW hypothesis?
Isn’t a good thing global temps have recovered 0.75C since the end of the Little Ice Age? Won’t this small amount of warming make winters milder, extend growing seasons, increase arable land area in the Northern latitudes, slightly increased precipitation, extended treelines, etc.?
Where is the catastrophe?
How long will this insanity continue?
Watch out for the claim of herbicides increasing yields. Usually it’s the reverse. Roundup Ready crops are resistant, not immune to glyphosate. The crop recovers and the weeds die. If you sow an RR crop into a weed-free paddock and use tillage for weed control, the yield is considerably higher.
Here’s an experiment you can conduct at home if you have a spare patch of grass and clover lawn. Spray off a patch with glyphosate (Roundup/Zero) and inspect it every few days. At first it looks as though both clover and grass will die, but after a couple of weeks, while the grass is dead, the clover will be well on the road to recovery. Selective herbicides are designed to increase profits, both of the manufacturer of the herbicide and the farmer. Chemical ploughing is supposedly less expensive than mechanical ploughing. Very often it’s used to conserve organic matter and topsoil.
The Pompous Git– Obviously, since farmers use herbicides, they serve a purpose. If herbicides decreased profitability and/or crop yields, then farmers would stop using them…
Many of my relatives are farmers and I worked many summers on my grandfather’s farm.
Trust me, farmers know what they’re doing; at least the ones that still remain in business. Many farmers have gone out of business or have been bought out by large farm conglomerates, but that’s just how the market works.
In the 1930’s, there were about 7 million farms in the US. Now there are only around 2 million farms and only about 2% of the US population actually work on them (used to be around 30+% in the1900’s).
Farming is a very tough and competitive business. If you don’t get everything exactly right, you go bankrupt… I think I read somewhere that only 25% of family-owned farms make more than $50,000/yr in profit. A typical profit margin for a farm is just 9% (used to be closer to 30%)….
Perhaps you should read what I wrote, rather than what you wish I wrote:
The rule of thumb I was taught was that selective herbicides decrease yields in cereal crops by 10–15%.
That the climate has an impact on crops is not new: grapes were harvested farther North in Europe during the warm Roman period, and Greenland was green.
That the climate has an impact on crop yield variability will remain unknown for a very long time, if at all possible.
Why should a slow and steady change have an impact on short term variability? Is it important?
No control experiment can be undertaken (crop with climate change compared to crops without climate change).
And if other long term observations could serve to seek correlation with climate change, then all other parameters would need to be filtered out, such as short term weather variations (1 to 7 seasons involving many individual parameters), agronomic changes (plant varieties, fertilization, pest control, etc.).
To get statistical significance would require an impossibly gigantic set-up, and centuries.
Historic records will not provide such data. Models are worse.
Useless study, and, most probably, totally wrong (there is a 99.99% confidence that it is totally wrong, the rest leaves room for partial correctness).
If the people doing it were actually intelligent, they would dedicate their efforts and intelligences to more purposeful endeavours.
The world warmed 0.12ºC per decade during 1951-2012, according to the IPCC (AR5 Summary for Policymakers, p. 5), which implies an overall warming of about 0.72ºC. What happened to global average wheat yields during that period?
I haven’t found data for 1951-1960. However, average global wheat yields increased by 33% in the 1970s, 27% in the 1980s, 20% in the 1990s, 9% in the 2000s, and 10% during 2010-2014. Average yield was 149% higher in 2010-2014 than in the 1960s (my calculations based on USDA data: http://www.ers.usda.gov/datafiles/Wheat_Wheat_Data/Yearbook_Tables/World_Production_Supply_and_Disappearance/wheatyearbooktable03full.pdf).
Similarly, average global output increased every decade and during the past five years. Average output was 157% higher in 2010-2014 than in 1960-1969, increasing 16% in the 1990s (allegedly the warmest decade of the millennium) and 12% in just the past five years.
That is all the more remarkable considering that Russian grain production fell by nearly 40% in the 1990s after the collapse of the Soviet Union (http://dash.harvard.edu/bitstream/handle/1/9556127/Hamm_gsas.harvard_0084L_10406.pdf?sequence=1).
If recent history is any guide, the ingenuity of farms will continue to trump climate change over the next several decades.
I doubt, this type of research has any meaning yet all. Crop yields are highly variable under irrigated agriculture and under rainfed agriculture. How, any body could estimate a decrease in yield with climate change. What is climate change? Climate is represented by several meteorological parameters. Crop growth is affected by different parameters while development is affected by different parameters. The soil type plays important. Some of these I discussed in my two books available at http://www.scribd.com/Google books — Agromet/Agroclimatological methods: As applicable to dry-land agriculture in developing countries [1993] and “Green” Green Revolution: Agriculture in the perspective of climate change [2011]. Let me give an case: In late 70s, ICRISAT.Hyderabad tested a model developed at AM Texas, known as “SORGF”. They conducted experiments in India as well some other developing countries [collaborative experiments]. With this data the model was tested for its application to tropical countries. The correlation coefficient achieved with biomass and grain yield was very low. Then they tried by changing energy sub-model and yet no improvement. At the meeting, the Director General of ICRISAT Dr. Swindale [a former professor from Soils from Hawaii University] asked me to change the water balance sub-model with my model [ICSWAB — published in International Agricultural Meteorology Journal in 1983]. The modified results were presented at the next day meeting. The correlations improved significantly [around 0.3 to around 0.8]. Also, a series of papers appeared in the same journal on the energy efficiency terms. My comment on these articles were also published in 1994. That means,in tropical countries energy factor is not that much important as that in extra-tropical countries. In tropical countries moisture is the major limiting factor. Also, in India the wastage of food is as high as 40-50%. This I presented on All India Radio talk in 2010 and the Finance Minister said the same in his 2011 budget speech.
In 2008, when with the mis-use of water in a dam, the Rabi paddy crop in the state of Andhra Pradesh in India has no water, then the Chief Minister of the state used innovative technique [bore wells in river Godavari] and resulted bumper yields. These are nothing to do climate or weather.
Dr. S. Jeevananda Reddy
# “climate change accounts for only 1/3 of crop yield variation”
… and the other 2/3 is due to …
… is due to …
… is due to …
WHUT
“More than 60 percent of the yield variability can be explained by climate variability in regions that are important producers of major crops, including the Midwestern U.S., the North China Plains, western Europe and Japan.”
All being regions that will get adversely effected by increased negative NAO/AO in the weaker part of this solar minimum from late 2015 to 2024. Also more frequent El Nino will increase drought in Australia, and with increased positive Indian Dipole events increasing drought in India/Indonesia. I doubt that Asia will be that resilient, especially India. For example the Agra famine of 1837/38, that kind of weather is just round the corner through 2016/17.
I would say the climate change, that has been in part generated by humans, had taken already a big toll. And it also costed alot of money, spent with intention or circumstancially…..