Bruce Hall alerts me to this headline from Eurkekalert which reads:
But the real headline behind the headline is this one, at the actual source:
Hmm, “estimate risk” and “increases risk” are bit far apart, and the article even talks that headline down:
Climate experts estimate risk of rapid crop slowdown
BOULDER – The world faces a small but substantially increased risk over the next two decades of a major slowdown in the growth of global crop yields because of climate change, new research finds.
The authors, from Stanford University and the National Center for Atmospheric Research, say the odds of a major production slowdown of wheat and corn, even with a warming climate, are not very high. But the risk is about 20 times more significant than it would be without global warming, and it may require planning by organizations that are affected by international food availability and price.
“Climate change has substantially increased the prospect that crop production will fail to keep up with rising demand in the next 20 years,” said NCAR scientist Claudia Tebaldi, a co-author of the study.
Stanford professor David Lobell said he wanted to study the potential impact of climate change on agriculture in the next two decades because of questions he has received from stakeholders and decision makers in governments and the private sector.
“I’m often asked whether climate change will threaten food supply, as if it’s a simple yes or no answer,” Lobell said. “The truth is that over a 10- or 20-year period, it depends largely on how fast the Earth warms, and we can’t predict the pace of warming very precisely. So the best we can do is try to determine the odds.”
Lobell and Tebaldi used computer models of global climate, as well as data about weather and crops, to calculate the chances that climatic trends would have a negative effect of 10 percent on yields in the next 20 years. This would have a major impact on food supply. Yields would continue to increase but the slowdown would effectively cut the projected rate of increase by about half at the same time that demand is projected to grow sharply.
They found that the likelihood of natural climate shifts causing such a slowdown over the next 20 years is only 1 in 200. But when the authors accounted for human-induced global warming, they found that the odds jumped to 1 in 10 for corn and 1 in 20 for wheat.
The study appears in this month’s issue of Environmental Research Letters. It was funded by the National Science Foundation (NSF), which is NCAR’s sponsor, and by the U.S. Department of Energy (DOE).
More crops needed worldwide
Global yields of crops such as corn and wheat have typically increased by about 1-2 percent per year in recent decades, and the U.N. Food and Agriculture Organization projects that global production of major crops will increase by 13 percent per decade through 2030—likely the fastest rate of increase during the coming century. However, global demand for crops is also expected to rise rapidly during the next two decades because of population growth, greater per-capita food consumption, and increasing use of biofuels.
Lobell and Tebaldi set out to estimate the odds that climate change could interfere with the ability of crop producers to keep up with demand. Whereas other climate research had looked at the crop impacts that were most likely, Lobell and Tebaldi decided to focus on the less likely but potentially more dangerous scenario that climate change would reduce yield growth by 10 percent or more.
The researchers used simulations available from an NCAR-based climate model (developed by teams of scientists with support from NSF and DOE), as well as several other models, to provide trends in temperature and precipitation over the next two decades for crop-intensive regions under a scenario of increasing carbon dioxide. They also used the same model simulations without human-caused increases in carbon dioxide to assess the same trends in a natural climate.
In addition, they ran statistical analyses to estimate the impacts of changes in temperature and precipitation on wheat and corn yields in various regions of the globe and during specific times of the year that coincide with the most important times of the growing seasons for those two crops.
The authors quantified the extent to which warming temperatures would correlate with reduced yields. For example, an increase of 1 degree Celsius (1.8 degrees Fahrenheit) would slow corn yields by 7 percent and wheat yields by 6 percent. Depending on the crop-growing region, the odds of such a temperature increase in the next 20 years were about 30 to 40 percent in simulations that included increases in carbon dioxide. In contrast, such temperature increases had a much lower chance of occurring in stimulations that included only natural variability, not human-induced climate change.
Although society could offset the climate impacts by planting wheat and corn in cooler regions, such planting shifts to date have not occurred quickly enough to offset warmer temperatures, the study warned. The authors also found little evidence that other adaptation strategies, such as changes in crop varieties or growing practices would totally offset the impact of warming temperatures.
“Although further study may prove otherwise, we do not anticipate adaptation being fast enough to significantly alter the near-term risks estimated in this paper,” they wrote.
“We can’t predict whether a major slowdown in crop growth will actually happen, and the odds are still fairly low,” said Tebaldi. “But climate change has increased the odds to the point that organizations concerned with food security or global stability need to be aware of this risk.”
About the article
Title: Getting caught with our plants down: the risks of a global crop yield slowdown from climate trends in the next two decades
Authors: David B. Lobell and Claudia Tebaldi
Publication: Environmental Research Letters – doi:10.1088/1748-9326/9/7/074003
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These people really need to be held accountable for wasting somebody’s money and continuing to completely mislead.
I forecast crop yields and changes to crop conditions (and market price changes) based on the effects of weather for a living.
Increasing CO2 has and will continue to have benefits to crops and world food production. They are stating the opposite with regards to the future.
To also state that the chance of a slow down from a natural cycle is only 1 in 200 is really dumb. Have they not heard of the Dust Bowl? This was a widespread natural drought that lasted almost a decade less than a century ago in the 1930’s.
My opinion is that the chance of a natural cycle slowing down yields is greater than 1 in 10. If we had any sort of substantial cooling, the negative effect would be tremendous.
When you factor in increasing CO2, that risk goes down for numerous reasons.
1. Atmospheric fertilization
2. Drought tolerance
3. Less chance of having the major yield reducing temp factor…….cold
Their conclusions are completely the opposite of reality. Natural cycles contain almost all the risk, increasing CO2 buffers that risk.
There would be a smaller yield reducing potential from heat, however, the modest and mostly beneficial global warming has been greatest in higher latitudes.
This still might effect corn pollination and kernel filling if excessive during that key developmental phase but in higher latitudes, not accumulating enough growing degree days(heat units) is sometimes a problem.
@saywhat
except that there is no [global] warming anymore
However, there may be some local warming in north america,
which is due to a decrease in precipitation at the higher latitudes
due to the [global] cooling
…////
it ‘s [getting] complicated…..
http://blogs.24.com/henryp/2013/04/29/the-climate-is-changing/
I remember I studied precipitation in Winnipeg and found it was going down,
exactly as predicted by me/
before I checked it.
From the article
“Stanford professor David Lobell said he wanted to study the potential impact of climate change on agriculture in the next two decades because of questions he has received from stakeholders and decision makers in governments and the private sector.”
==============================================
There’s the money quote, so to speak. A 20-year grant ought to see Lobell through to retirement.
• Elevated carbon dioxide increases the productivity and water use efficiency of
nearly all plants.
• Higher levels of atmospheric CO2 ameliorate, and sometimes fully compensate for,
the negative influences of various environmental stresses on plant growth, including
the stress of high temperature.
• Health promoting substances found in various food crops and medicinal plants have
been shown to benefit from rising atmospheric CO2.
• Elevated CO2 reduces, and frequently completely overrides, the negative effects of
ozone pollution on plant photosynthesis, growth and yield.
• Extreme weather events such as heavy downpours and droughts are not likely to
impact future crop yields any more than they do now.
• On the whole, CO2-enrichment does not increase the competitiveness of weeds
over crops; higher atmospheric CO2 will likely reduce crop damage from insects
and pathogenic diseases.
• In addition to enhancing forage productivity, atmospheric CO2-enrichment will likely
not alter its digestibility by animals.
http://www.plantsneedco2.org/html/PositiveEffectsOfCO2OnAgriculture2.pdf
“…the “increase in CO2 from glacial to postglacial levels [180 to 280 ppm] caused a significant gain in vegetative biomass of up to 40%,” together with “a reduction in the transpiration rate via decreases in stomatal conductance of ~35%,” which led to “a 70% increase in water use efficiency, and a much greater productivity potential in water-limited conditions.”
http://www.co2science.org/articles/V11/N22/EDIT.php
If someone really thought this they should be for an international agency that creates excess demand for food grains. Almost every year it would be turned into ethanol and sold. But if there were droughts & famines – it would just be sold.
Perhaps there is a mini ice-age or a stratospheric volcano. Or both. Producing something like another “year without summer” — food supply would not have time to catch up to demand.
My point is, CO2 would not have been the problem.
DHR and McComberBoy:
“Did the study include the effects of increased CO2 on plant growth?”
———————————————————————————————————–
From the study:
“For this analysis, we assume that positive effects of
elevated CO2 on yields will continue over the next 20 years at
the same rate as has occurred in recent years. That is, because
the changes in CO2 are very gradual and linear over time, we
assume that CO2 changes will not cause any deviation from
historical yield growth rates and can thus be ignored in our
analysis of a possible yield slowdown.”
———————————————————————
Which seems a bit suspect- they can assume C02 won’t make changes to the yield rate any differently than it already has, but why wouldn’t they assume the same for temperature changes- hasn’t increased C02 been affecting temperatures in the past yield rates as well? Good catch!
In 1960, the US yield for corn = 54.7 bu/ac, wheat =26.1 bu/ac and soy beans =25.2 bu/ac. In 2009, US yield for corn = 161.9 bu/ac, wheat =44.9 bu/ac and soy beans =52 bu/ac. Most of these gains can be attributed to technological innovations, e.g., fertilizers, seeds (including pest resistant seeds), soil preparation, etc,. BTW, the US isn’t the world leader in some areas of high-yield agriculture production.
Why shouldn’t increases in agriculture production yields be expected to continue?
Jtom says:
July 27, 2014 at 9:35 am
Direct measurements (not models, so it is untrustyworthy data (sarc)) showed that on high growing days in the UK, wheat stopped growing in the late afternoon.
_____
Very interesting. Suggests that we are well below optimal CO2 levels. Do you have a reference?
Seems the boys in Boulder and their counter parts have been partaking of the 5 leaf weed a bit to much. (or this is a bad case of scientific perversion)
The current CO2 increase has caused 0.0 deg C rise inf temp when natural variation is considered. The Current stop in warming has cooled farming regions thus slowing production naturally and has nothing to do with Man Created Climatic Change.
Historically, the MEWP saw great crop increases even when some areas formed desert conditions as other areas became aridible and crop productions soared.
I find it hard to believe they can contain a trace gas to an area and then claim its effects in minuet micorclimates when they cant even get a simple weather prediction to pan out at greater than 24 hours at a 95% confidence level in a small area. There is so much wrong with this paper and so much gibberish eco-terroist crap in it and none of it can be supported by historical comparison.
The low information voter who can not understand simple scientific concepts will be scared that they are going to starve and that is what they wanted. As emotion increases the ability to logically reason decreases. This is intentional misdirection and lying to support an agenda.. Get them scared with lies and then have the government come in and save them with more intrusive regulations.
This is paper is nothing more than perverted science propaganda and has no scientific value. Just casually looking at it and its base claims, even I can see it is ridicules. These folks need to just come out and admit they are scientists for hire and they will produce whatever you want to the highest bidder…
JimS is correct: Warming temperatures = longer growing season = less risk of frost = stupid alarmist climate models.
With the current “pause” actually being a nascent cooling trend, we should really be concerned about reduced crop yields resulting from cooler global temperatures, shorter growing seasons, and increased risk of frost.
From my Aggie perspective, the article was a bunch of malarkey.
“However, global demand for crops is also expected to rise rapidly during the next two decades because of population growth, greater per-capita food consumption, and increasing use of biofuels.”
Well, just stop subsidizing biofuels.
This entry was posted in Agriculture,
This entry should be posted under Climate Agnotology.
I read the entire post and think I lost at least a few IQ points, which I hope I gained back reading some of the comments.
I forgot to add this article is specifically designed for a media blitz to create fear… Just what politicians losing the battle on Climate Change want.
Jtom says:
July 27, 2014 at 9:35 am
===
yep…they “stop” growing at 150ppm…..but at 180ppm CO2 levels are so limiting…their growth is so slow…. atmospheric levels stabilize
That’s what happened…..that is the only logical explanation
earwig42 says:
July 27, 2014 at 10:22 am “I read the entire post and think I lost at least a few IQ points, which I hope I gained back reading some of the comments.”
…not to worry, our new I.Q. modeling algorithm increases I.Q. scores by 4 to 6 points per decade of increased age. It’s linear, like AGW, or switch to plus 4 to 6 percent per decade to achieve logarithmic I.Q. growth, like CAGW. 🙂 Of course, there is some grant funding to support the I.Q. modeling agenda.
What a cesspool of useless conjecture.
Stanford professor David Lobell doesn’t have the slightest idea what the future of food crop production will be, he doesn’t have anything useful to tell those who supposedly him questions and doesn’t know what they can do with the nonsense he did provide.
This reminds me of Jane Lubchenco’s suggestion that a National Climate Service would be helpful in locating wind farms and various government facilities based on defining what and where future weather will be. As if.
I don’t believe the professor truly received the type of “questions from stakeholders and decision makers in governments and the private sector” which sought what he then studied and provided.
In the end his work is GIGO gibberish.
Lobell. “..we can’t predict the pace of warming very precisely. So the best we can do is try to determine the odds.”
Yet he asserts those concerned with food security or global stability need to be aware of his unreliable and worthless crap shoot guesstimation?
Someone paid him to play with computer models and produce meaningless conjecture that was no more reliable than simply assuming there must be some impact ahead.
Not a single stakeholder or decision maker in government or the private sector can use anything he has provided for any policy or decision whatsoever.
It will simply be added to the heap of demagoguery and pile of ideological idiocy used to advance the purposefully mendacious AGW movement.
They can now model a natural variability! An achievement worth several Nobel Prizes. There are still some very modest researchers.
I think the gist of the article is, “give me money and I’ll study it”.
richardscourtney wrote:
the article is a warning that biofuels crops will displace food crops if rising temperatures induce governments to subsidise and/or to mandate use of biofuels.
===========
What Richard says would actually be a “shift” in crop use and cultivation in warmer world, that affects FOOD production, product utilization, and thus prices. Such a shift is driven, as Richard suggests, would be by human economic decisions, not nature. That is trivially true, but that is not what title or abstract suggests.
Without reading through the entire MS, the abtract simply states, “a major slowdown in the growth of (corn and wheat) yields” in a climate change (i.e. human-released CO2 forcing of temps) world.
In agriculture science, the term “yield” is very clear. It is bushels per acre for corn and wheat. Better seeds, GM hybrids, fertilizer selections, watering/rainfall, insects, disease all affect yield. All things being equal, longer growing seasons and more CO2 will increase the increases in yield, not slow them down.
Prediction: these kinds of alarmist claims are an embarrasment to science, and one day as a direct result, climate scientists who pushed these then falsified (by time and nature) claims will be publicly mocked and derided.
The paper didn’t seem to factor in sun cycles 24 & 25’s good odd of bringing on another grand minimum event with dramatic cooling and the impact it will have on crops.
When they were talking about climate change being the problem that would result in a reduced crop yield, I coulda sworn they were talking about a cooling world with a reduced growing season….
maybe in some crazy way the scientists are trying to warn us, but never quite out themselves as not believing in CAGW
Joel O’Bryan:
At July 27, 2014 at 11:00 am in a comment you make on my post at July 27, 2014 at 7:18 am you write
Long ago (memory says 2001) Fred Singer organised a side-meeting at an IPCC Conference. The Meeting room was filled (with no remaining standing room) with members of Greenpeace and IPCC Representatives. Fred Singer, Gert Rainer-Webber and I each gave presentations and I spoke on global temperature data sets.
I concluded my presentation by making this prediction
I have yet to see any reason for me to change any word of that.
Richard
Globaloney headline enhancement:
“Global Warming is bullshit” becomes:
“AGW may generate toxic levels of manure odor.”
richardscourtney says:
July 27, 2014 at 11:22 am
When the ‘chickens come home to roost’ – as they surely will with efluxion of time – then the politicians and journalists won’t say, “It was all our fault”. They will say, “It was the scientists’ fault”, and that’s me, AND I OBJECT!”
If it makes you feel any better, and it may not, it is not the scientists’ fault that the politicians and journalists are failures in this arena.
“Willis Eschenbach says:
July 27, 2014 at 8:49 am
Here’s the reality, dear boffins. Farmers change what they plant with the weather, even year by year. If it is going to be dry, or it looks like a shorter growing season because the spring is late, they plant varietals adapted to dryer weather or shorter growing-seasons, or they plant something else entirely. And of course if there is a much longer general swing in the temperature or the rainfall, they adapt to that as well.”
That’s all true…if you don’t grow GMO crops.
I’m against GMO crops for two reasons, the first being I don’t believe the ‘life’ should be patentable. The second is because, for the most part, the varieties available are limited. They don’t have the number of choices to be able to follow a planting scheme based on weather. The ones out there now are pretty much ‘all purpose’ varieties that do ‘alright’ in a wide variety of conditions, but don’t really excell under any. Basically, that means if you are growing GMO corn you have 120 day corn or you have 100 day corn, and if you had a late spring and need an 85 day corn you are out of luck…just hope for a late fall. To me this makes them much less valuable, to the point of ‘why bother’ in many cases.
I didn’t expect the authors of the paper to grasp the concept that all varieties of corn or wheat are different and the choice of which variety to grow has a lot of thought and planning (along with a careful eye to local climate and weather). Choosing the ‘correct’ varieties often makes a ‘good’ harvest into a ‘great’ one.
The assumption made in this and numerous other papers by warmists is that the climate is warming. That is abject nonsense. There has been no warming for the last 17 years and there is none in sight. The climate models they use all slope up in the future, indicating warming, while the actual global temperature is a horizontal line, no warming since the late nineties. The upward slope of those climate model predictions comes from the fact that they all have a built-in code that makes increase of carbon dioxide equivalent to increase of global temperature. This of course is complete stupidity because carbon dioxide has been increasing for the last 17 years while global temperature has stood still. Their built-in model code nevertheless takes that carbon dioxide increase and creates those asinine warming curves we see in CMIP5. They have a further problem with their greenhouse warming theory. The Arrhenius theory they use is set up to predict warming when carbon dioxide increases. And it has been doing that faithfully for the last 17 years while nothing happened. If your theory predicts warming and nothing happens for 17 years you as a scientist know that this theory is worthless and belongs in the waste basket of history. The only theory that can correctly handle the current greenhouse effect is the the Miskolczi greenhouse theory (MGT) of which I have spoken at length before. Its prediction is exactly what we see today: there is no warming at all despite a steady increase of atmospheric carbon dioxide. This is explained as a consequence of the interaction of two greenhouse gases, carbon dioxide and water vapor, in the atmosphere. Arrhenius fails because it can only handle one greenhouse gas and is incomplete.