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
I’m a little more concerned about ‘superweeds’ and their effect on our dependance on industrial scale monoculture farming. In the US we already have up to 70 million acres of U.S. farmland had glyphosate resistant weeds in 2013. It seems this will be a reoccurring problem as natural plant evolution quickly adapts. Google ‘superweeds’ for more info.
http://www.stltoday.com/business/local/midwestern-farmers-wage-war-against-superweeds/article_e84e6049-ac33-562a-aa54-e9a564af8e6b.html
Rick Werme says:
Lmao! Good eye!
richardscourtney says:
July 27, 2014 at 7:18 am
…
Farmers will produce the most profitable crops. Behind all the waffle, 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.
The article is right for reasons I explained here.
Richard
________________________________________
It’s the law of free markets that the most profitable crops are produced. Basically, there is nothing wrong with that. More important is the waste of foodstuffs. As long as an estimated 30% of all foodstuffs ends in the dustbin and not the stomachs, there is no reason to worry about biofuels.
Stop squandering of what we already have in the first place!
More Lobel GIGO. I posted on the two original bad papers (US and CYMIT African maise) here and at CE in 2011. A better more complete explanation is in my first book. Taking a spurious statistical threshold result based on an improperly formulated regression model, then use GCMs that themselves do not reproduce reality (the pause) to estimate the risk of yield reduction is absurd. Two bad results multiplied together do not make a good result. It’s GIGO.
And to a question posted above, no, Lobels results do not take into account co2 fertilization. They are strictly based on yield impact of degree days above an (improperly) statistically determined threshold much lower than in actual greenhouse experiments, and much longer in duration than anthesis, because the model omitted a heat plus moisture covariance term. Plus in Lobels African data, all the experimental plots were much dryer than minimum ‘optimal’ since the whole point was to breed drough resistant corn for Africa, where on average only about 40 % of optimal pecipitation exists, most coming in only 3 months during the MAM long rain rather thannthe optimal 4-5 months. There is yield reduction given hot plus dry, but not given hot plus wet. And in both cases, hot has to be hotter than the spurious threshold.
…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.
Did they also estimate the odds without biofuels?
Here is the key statement-
“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.”
They claim to have climate models making believable regional predictions 20 years into the future, even though past performance has been a shambolic joke. Moreover, they claim up to a 40% chance of a 1 C increase in 2 decades, or 0.5 C/decade, even though current trends (with record CO2 emissions) are essentially 0.0 C/decade.
This article is eco-gibberish, which is why it is destined to become a canonical underpinning of new EPA CO2 regulations.
Joel O’Bryan says:
July 27, 2014 at 7:01 am
“I didn’t realize corn and wheat could read political propaganda. How else would a corn plant know why it is warmer?”
Exactly Joel. Do the brainless authors of this paper really expect me to believe that the corn and wheat plant (or any plant for that matter) can tell the difference between natural and manmade warming and can tell when there is a mix of the two? And do they expect me to believe the two plants will react differently and produce a varying yield depending on the warming type?
I’m not even a scientist and that notion still sets off the B.S. alarm in my head. This demonstrates the degree to which climate science has been corrupted by the politicization of it and the tax dollars flowing into it, and it is getting truly tragic.
History contradicts these so called experts. During the Medieval Warm Period agriculture flourished. Many think this was a major contributing factor to the Renaissance.
I wonder if there is a computer model that will tell us how much crop yields will decrease and how much starvation would occur if we stopped using hydrocarbons completely. What if we could not use tractors and modern fertilizer? What would happen to crop yields? What if there were no trucks to transport produce to markets? How many people would soon starve because of not knowing how to grow food for the year and not having adequate refrigeration due to lack of electricity to keep food fresh longer and living in cities far away from any farmland? (Note: I am making the safe assumption that nuclear power plants won’t be built at a rate to replace fossil fuel electricity and all other “renewable” energy is not sufficient to handle our energy requirements.) How long will our forests last due to people cutting down every tree for cooking and heating?
There is no money modeling the negative consequences of giving up oil, coal, and natural gas.
“major slowdown in crop growth” = more crops every year ,,, just not as much as there has been over the last 60 years ….
Remember when the AGW cult used to predict less crops?
NO NO NO! Plants grow according to what the models say, not based on reality. And any such plants that deny the model are simply wrong. It is settled.
…… reality and models are drawn from the same population: Not
“… caught with plants down …” Reversed author listing from six years ago, and a playful title: what else changed? @ur momisugly http://www.climatecentral.org/about/people-bio/claudia_tebaldi
cf. C. Tebaldi and D. B. Lobell (2008), Towards probabilistic pro jections of climate change impacts on global crop yields. Geophysical Research Letters. , Vol. 35, L08705, doi:10.1029/2008GL033423
** Co-author with R. Knutti, as recently as 2011. None cited since.
** Michael Kile, http://quadrant.org.au/opinion/doomed-planet/2014/03/guessing-games-climate-science/ closes with “… David Whitehouse explains in The Very Model of a Modern Major Problem, “is that the various outputs of computer models are not independent samples in the same way that repeated measurements of a physical parameter could be. They are not independent measurements centred on what is the “truth” or reality.”
Given this, does the addition of more models and “experiments” force the mean of a multi-model ensemble to converge on reality? Some, such as the work by Professor Reto Knutti believe it doesn’t. I agree, and think it is a precarious step to take to decide that reality and models are drawn from the same population.”
– –
I agree with Kile: “Something is rotten at the Climate Carbon Cargo Cult Club (CCCCC).”
best regards, John
The other thing I like about the article is the intrinsic bias. How will things go? Well, that depends on how bad the warming is. If it is simply an alarming increase in temperatures, then it will be this way, but if it is an alarming and SHOCKING increase in temperatures, then it will be that way.
Still not a hint of any author daring to say “if temperatures do not rise”.
And yet during the recent fast temperature rise prior to the pause, a segment in time used to prove anthropogenic globull warming, crop production soared. But not because of climate. It soared because of improvements in soil, planting and crop growth practices, irrigation and disease management, and seed development.
I bet our highly intelligent farmers just love it when climate scientists predict they won’t be able to do their job because of weather. Hardly. The biggest impediment to farmers doing their jobs is the government.
The part of these papers that always makes me laugh is that they think that farmers are idiots who will continue to plant e.g. a specific strain of corn, or corn at all, if the conditions for one kind of corn prove unfavorable.
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.
And as a result, any projections of either yield or production which do NOT take the farmers into account are worse than useless, because they are actively misleading.
I gotta say it … pathetic. Those guys need to go live on a farm for a few years to disabuse themselves of their childish suppositions about farmers.
w.
Climate Change, When the AGW people made the change from global warming to Climate Change
they must have overlooked that climate change is an open ended condition when applied to
temperature.
Climate can either be warming or cooling!
Surprise, climate is now cooling! Just suppose we are in the beginning of a new Little Ice Age period. We will then see a large drop in food production!
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
====
so……they don’t even give it 50/50…even odds
Willis wrote:
Historically farmers have been able to do this because of accurate (within reason) forecasts. Given the bias in the US toward models that put data in and get climate warming out it is unlikely farmers will get the degree of accuracy they’ve had. If so the result will be more crop failures as a direct consequence of climate warming bias in the predictions. I agree with the OP that there will be crop failures but not because of climate change – the reason will be predicted climate change at odds with observed. We already have nearly 20 years of this, and it can’t continue without impacting farmers dependent upon misguided loans and grants policies from a misinformed USDA (US Dept. of Agriculture). I would not be surprised to learn this is already happening but if it is it should be another tool in the skeptic tool box.
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.
Really? Why, exactly? How was that determined? Show your work, fellas, or I call BS.
Any skeptic can have a field day with this nonsense. Warmer weather “slows yields”? What’s that supposed to mean? The big worry here is the “…risk of a rapid crop slowdown..” wherein the researchers assert they can rapidly detect their own lower estimates amidst projected higher yields, a special kind of ad hoc illogic seemingly based on the misconception that longer growing seasons result in reduced harvests, but this bit really caught my eye:
Now there’s a lovely thought. Already there are people too obese to walk. No shortage of cooking and food shows on the boob tube however, even with no US state able to maintain an obesity rate below 20%, and 12 with obesity rates at 30% or greater.
So the alarmists probably are right about greater per-capita food consumption, if nothing else.
Just to add a little tidbit of info to the debate:
Most vegetation is C3 plants. They use soley atmospheric CO2. Wheat and rice are examples (corn is C4, and can use CO2 from the soil). C3 plant growth will befing slowing if levels drop below 220ppm, and stop below 150 ppm, or so.
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.
How could that be, considering CO2 levels were above 150ppm? Imagine hundreds of acres of C3 plants taking CO2 out of the atmosphere. The CO2 level of the LOCAL environment was dropping below that needed for the wheat to grow (unlike the mystical trees of Yamal, it seems wheat crops respond to the local environment, not global averages).
If man-producted CO2 stopped and reversed the decline of atmospheric CO2, then he staved off a gobal disaster. Crops were already undernurished wrt CO2, every ppm reduction in the future would further reduce crop yields.
I would love to see a study of what wheat and rice yields would be if the CO2 levels were at 185 ppm.
In my opinion the approach adopted by Tebaldi and Lobell ignores the fact that plants live on our planet since millions of years (and so they are adaptable to a wide range of environmental conditions) and that at present agricultural activity is carried out by billions of farmers (which can take their business decisions much faster than the industrial sector – as stated by Willis Eschenbach).
These facts make the food producton system extremely adaptable with respect to climate change and the adaptation follows three main pathways:
1. the plants react in a non-linear way to the environmental variables and more specifically to temperature variations (contrary to what suggested by the authors, which have addressed their problem with a linear approach)
2. if climate changes the farmers can change their crops very quickly (for example, from corn to wheat or from wheat to rice)
3. in the same way, if climate changes farmers can change their varieties very quickly adopting the most suitable for the new climate (e.g.: if the length of the growing season increases farmers can choose varieties wth longer cycle with a significant increase of yield – e.g. for maize we ranges from the extra-early varieties of class 100 with emergence-harvest period of 80 days to extra late varieties of class 800 with emergence-harvest period of 140 days).
These strategies of adaptation (that should be well known by scientists because they are in place since the birth of agriculture, about 10000 years ago) justify the phenomenon that despite IPCC states that the AGW is at work since decades, FAO statistics show the persistence of a robust global positive trend of the major crops (wheat, corn, rice, soybean).
Obviously, the plasticity of the agricultural system should be promoted by suitable policies, either by stimulating the abovementioned adaptation pathways and by promoting research to develop varieties suited to the changing climate (note that the potential for adaptation present in the genes of cultivated plants is huge and largely unexplored). In this sense, genetic engineering techniques are a tool extremly powerful and should be exploited to the fullest.
In this context, as stated by Richard Courtney, the competition of the biofuels with food should be evaluated more stringently than we do at present.
Befing = begin
Sigh.
It’s Final — Corn Ethanol Is Of No Use
http://www.forbes.com/sites/jamesconca/2014/04/20/its-final-corn-ethanol-is-of-no-use/
Our new improved education system leaves out the ability to read, so the rhetoric from climate change fear mongering goes unchallenged by deliberate efforts to keep the morons glued to Facebook, texting, etc…
Right you are, Pamela! (July 27, 2014 at 8:35 am) This is a ‘Club of Rome’ type prediction. This is a Kaya identity type prediction. False assumptions + linear trend computer models = Useless Information.
First of all, look at a world map. If the warming were to take place, favoring the higher latitudes, the amount of viable farming acreage would expand rapidly on the northern end. In the lower latitudes, the temperature changes would be less and farmers would easily adapt or shift to a crop that is more heat tolerant. Bio genetics will likely solve this problem, if it hasn’t already, so our lower latitude farmers will be just fine.
The thing that makes computer models so completely useless for such studies is that they lack adaptability and creativity algorithms. Nearly all of human progress from the beginning of time has been a function of creativity and adaptability. When we take these two functions out of the process of predicting our future, we will invariably come up with Malthusian results and ‘it’s worse than we thought’ proclamations. If we could calculate these two non-linear functions, we would find that our future would always be bright and promising, unless, of course, we also introduced the ‘government control’ algorithm, which has managed to trump the other two functions many times during human history.
The ‘government control’ algorithm is not inherently negative. When this algorithm actually supports adaptability and creativity, the results can be astounding. One such algorithm was expressed in this way: “…establish justice, insure domestic tranquility, provide for the common defense and PROMOTE the GENERAL welfare for ourselves and our posterity…” Too bad this algorithm is no longer being applied and has been rewritten to the point of becoming a net negative for humanity!
The other thing that caught my attention was the comparison with natural climate variability, which has always been grossly underestimated by these people. In effect, they were comparing a warming scenario with the status quo (little or no change). The status quo will always look better in a linear computer model without functions tracking creativity or adaptability. In addition, this model did not even consider a natural cooling over the next several decades. Certainly that would be MUCH worse for crop yields than an equal amount of warming.
NCAR and Stanford are doing a gross disservice to their clients. Their report will undoubtedly keep the grant money coming, but will ultimately be harmful to the farming community, if they are unwise enough to accept it.