Guest Post by Willis Eschenbach
I keep reading that increasing temperatures will cause decreasing yields of our food crops, resulting in widespread hunger … for example, the IPCC says:
Declines in yields and crop suitability are projected under higher temperatures, especially in tropical and semi-tropical regions. Heat stress reduces fruit set and speeds up development of annual vegetables, resulting in yield losses, impaired product quality, and increasing food loss and waste. … All models project an increase in the risk of hunger, with the median projection of an increase in the population at risk of insufficient energy intake by 6%, 14%, and 12% in 2050 for SSPs 1, 2 and 3 respectively.
But having grown up with farmers, this seemed improbable to me. Farmers are constantly modifying planting and harvest times, seed depth, irrigation schedules, and crop and varietal choices based on the weather in order to maximize yields. And they are very successful at it.
So I looked at the change in yields over time. I also included the change in airborne CO2 concentrations over the same period.
Figure 1. Percentage change in yields, ten major food crops, along with the percentage change in CO2.
Yields have been increasing, in fits and starts, despite increasing temperatures over the period of that record.
Today I realized that there was another way I could look at this. I figured that I could take a look at standardized crop yield by country versus the average temperature of the country, to see if the country’s temperature affected yield. Figure 2 shows the result for five different crops.
Figure 2. Yield versus temperature by country, 2020. All yield values are standardized to a mean of zero and a standard deviation of one. The dotted vertical line is at 18°C.
What I noticed when I plotted this up was that the yields fall into two groups—one for warm countries and one for cold countries. It was also obvious that the yields in the warmer countries were all lower.
So … why would this be? Well, my first thought was that it represented the difference between industrialized and non-industrialized nations. Farmers in industrialized nations have more fertilizer, tractors, detailed weather forecasts, refrigeration, machinery for plowing, seeding, weeding, harvesting, and the like. As a result, we’d expect industrialized nations to have higher yields. So to see which countries were where, I plotted up the temperatures, and divided them into those warmer and colder than 18°C.
Figure 3. Average temperatures, 2000 – 2020
Hmmm … almost all of the industrialized countries have an average temperature less than 18°C.
To close out the loop, I looked at the trends within each group of countries, those above and below 18°C. Here is that result.
Figure 4. As in Figure 3, but including the trend lines for each country group, above and below 18°C.
It turns out that within each group, the yields in the warmer countries are no better or worse than the yields in the cooler countries. And as a result, the claim that warming temperatures will cause widespread hunger is not supported by this analysis.
Onwards, ever onwards,
w.
PS: Although I can and am happy to defend my own words, I can’t defend your interpretation of my words. So I politely request that you quote the exact words you are discussing, so we can all be clear on your subject matter.
The data presented are very useful. But there is no scientific basis whatsoever to claim that higher temperatures produce lower yields including in areas with tropical climates. Biologically, reproduction and growth are biochemical processes – and as anyone who knows chemistry at all realizes that most chemical reactions take place at higher rates as temperature increases.
Plus there is the matter of growing seasons – even if tropical food production was reduced at warmer temperatures (it clearly isn’t), the vast majority of worldwide food production is performed in the far larger land masses of the temperate climate zone. A warming climate would obviously increase the length of the “growing season” in temperate climate zones, and therefore enable more food production and greater variety in food crops produced. Crops don’t grow in the winter in the temperate zones (even “winter wheat” does not grow in the winter – it is planted in the fall and lays dormant until the beginning of the spring growing season).
Therefore the net effect of a warming earth is affirmatively proven to increase food production, not reduce it.
Yup – warmer means better.
The analysis above does not mention a key error in the original claim that “tropics will become warmer”. There is no evidence for that. Broadly, the tropics hold constant with an increase in GHG’s because of the moderating influence of evaporated water – even over land as in the DR Congo.
In a “warming world” the tropics stay pretty much the same – hence the concept of polar amplification and discussion of the average. When there were crocodiles swimming in the Arctic Sea (which was not all that long ago) it was barely warmer in the tropics.
Essentially a warmer world will see a greater percentage of it as subtropical farmland. Well wouldn’t that be nice! One day oranges will grow in Canada. (Old prophecy.) When that happens it will probably have nothing to do with GHG’s, rather something to do with the oceans and the sun. I can’t wait for that time! I have already moved 12 degrees further north in anticipation.
Greetings from Lac Ste Anne (where we can still drive on the lake).
OK, Duane, it looked to me like your comment was correct…”increase food production”, but I decided to check it out. Google “optimum temperature for a greenhouse environment” and you get…wait for it…most crops do best at greenhouse temperatures of 18 to 24 deg C. Willis has presented his usual interesting data analysis and opened the door to some cultural differences, which is somewhere I am not going.
“But there is no scientific basis whatsoever to claim that higher temperatures produce lower yields including in areas with tropical climates.”
From: https://medcraveonline.com/OAJS/effects-of-high-temperature-stress-and-traits-associated-with-tolerance-in-wheat.html
The same applies for corn, etc.
Part of the issue here is that Tmax has been going down over much of the globe while Tmin has been going up. Higher Tmin values can actually increase yield. Yet when the CAGW alarmists speak of temperature going up they are typically speaking of mid-range values. Mid-range values can go up from higher Tmin values, not just Tmax.
It’s a complex issue. Everything from tillage practices to irrigation amounts to the amount of tilled land surface can affect global yields. But it is not obvious that the Earth turning into a cinder predictions have any credence at all and therefore predictions of crop failures have little credence either.
Was that research report from Pottsdam? Having grown up on a wheat farm, I laughed all the way through that Unicorn report.
Clemson University, USA, used to be called Clemson Agricultural College of South Carolina.
‘Photosynthetic rates exhibit a sharp decline when wheat plant is exposed to high temperature stress during vegetative or reproductive phase’
Overview. Wheat is the major winter crop grown in Australia with sowing starting in autumn and harvesting, depending on seasonal conditions, occurring in spring and summer. The main producing states are Western Australia, New South Wales, South Australia, Victoria and Queensland.
That’s why wheat is planted in Autumn, when it is cool.
The CSIRO selectively breeds hot strains of shatterproof, rust resistant, high protein wheat.
In Europe colder strains are used.
Australia used be the ‘granary of the Empire’.
We may be able to keep this up.’
https://www.farmonline.com.au/story/7539477/australian-wheat-crop-upgraded-to-a-bin-bursting-record/#:~:text=Australian%20wheat%20crop%20upgraded%20to%20a%20bin%20bursting%20record%20of%2034.429%20million%20tonnes,-Malcolm%20Bartholomaeus%20ANALYSIS
We just had a bin buster crop.
If Europe is to survive it needs our gas, coal and wheat.
Obviously, as sugar cane, sorghum, and cassava are doing less well, global warming is gonna kill us all right soon now/sarc
Perhaps reduced supplies of sugar might not be all bad?
From your fig.1, it looks as though the IPCC has been mistakenly using crop yields rather than temperatures in their predictions.
And if you Google “world food production graph” and select [Images] graph after graph after graph showing substantial increase over time will come up. However pointing that out to the true believers falls on deaf ears. If NPR tells them that wheat production is projected to decline, there’s nothing more to discuss and they change the subject to real pollution, guns, the evil Catholic church, proud boys, Trump or whatever, God knows they aren’t going consider that they are being lied to by the media about nearly everything.
nearly ? You are being charitable.
Thank you Willis for your usual thought provoking piece.
Of course all this is now academic as we are entering a real famine situation, unless the Ukraine situation is quickly resolved.%
As you know Russia produces the majority of the raw material for organic fertilizer, 40% of European energy, and together with Ukraine 60% of European grain. The majority of middle eastern countries and near Asian ones rely almost entirely on this source.
So no need for the Green Gang to worry about global warming.
Let’s ask the Ukrainians about upcoming crop yields shall we. The UN has become a facilitator for Russian expansionism.
You’re on board with Burisma as well? 😉
If you took every prediction of the IPCC and assumed the exact opposite to be true, you would have a reasonable working hypothesis for future outcomes.
Based on the most recent IPCC report, it is obvious that they are panicking as fewer and fewer are buying into their BS. The IPCC is just one working arm of the Globalist Davos crowd, Their plandemic just sort of petered out (as corona viruses are wont to do), and their desperation shows in the way Russia was set up in the Ukraine. Looks to me that the globalist agenda is rapidly falling apart, and if humanity can manage to survive the next several years, there will be a new world order–just not what the WEF had planned.
Yep, the major crisis of our time is the “politician crisis” and they know it. Cull the herd.
On the other hand, warmer temperatures are supposed to make trees grow faster.
Does the right hand not know what the left hand is publishing?
Ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha!
Oooo that was good.
So the maples formed a union
And demanded equal rights
“The oaks are just too greedy
We will make them give us light”
Now there’s no more oak oppression
For they passed a noble law
And the trees are all kept equal
By hatchet, axe, and saw
🤓
I am a Rush fan and that made my whole day.
The last two lines are my most oft-quoted lyrics. They seem so relevant today.
Just like all the AGW predictions if you tell a lie big enough and often enough people will start to believe it. However we are entering into a half a century of failed predictions that the people can witness themselves. All the media in the world won’t be able to support the AGW lies much longer, but they’ll keep trying.
A comment about figure 1. The only C4 crops in it are maize, sorghum, and sugarcane. C4 plants benefit much less from increasing CO2 than all the other C3 crops. Maize yield does well anyway because of all the hybridization and GMO. Sugarcane and sorghum, not so much. And sorghum is a human grain staple mainly in Northern Africa, where inadequate water and fertilizer play a role in yield.
None of the food crops today are in their natural state – they have all been selectively cultivated and in many cases hybridized and, god forbid, genetically engineered by humans over many thousands of year to maximize yield, flavor, color, texture, size, etc.
What we think of today as a corn stalk bears almost no resemblance to the pitiful seed grass of five thousand years ago. Ditto with wheat, and most other agricultural crops, plus the same is true of domesticated farm animals.
So if today, the existing corn varieties predominant today don’t benefit as much from increasing CO2 concentrations in the atmosphere, it is a foregone conclusion that hybridizers and genetic engineers will most certainly develop one or more new strains of corn that will benefit from higher CO2 concentrations. Ditto with all other agricultural products, both plant and animal. We’ve only been doing this for the last 10 thousand years without interruption.
There is always the hopeful possibility that our fearless but compassionate leaders will forbid such noxious meddling with plant destinies, putting an end to all those plant meddlers screwing up the models. Perhaps it is time for a new 5 year farm plan.
“A new 5-year farm plan?
I heard that Lysenko guy has some excellent ideas for improving crop yields. Let’s use his “science” for the new plan!”
— Average NPR Listener
(that considers themselves well informed)
This says, “Nearly all agricultural species — including C4 plants — respond positively to increases in the air’s CO2 content by displaying enhanced rates of photosynthesis and biomass production, as well as higher rates of water use efficiency.”
It shows a 120% increase in grain yield with a 160 ppm increase in CO2.
C4 plants evolved to tolerate hot/dry climates. They can continue to fix carbon while the stomata a closed, which means less water loss by evapotranspiration, but CO2 is the gas of life, and C4 plants will grow faster when there is more of it.
http://www.co2science.org/subject/a/summaries/agriculturemaize.php
“C4 plants benefit much less from increasing CO2 than all the other C3 crops. ”
I’ve heard this before and it always sounded like spin – listen, as long as C4 plants benefit from more CO2 then it doesn’t matter that c3 plants benefit more from the extra co2.
I’ve heard from farmers and researchers that corn plants can actually suck all the available co2 around it during peak growing season time and stop growing, literally starving until say, the wind blows and mixes up the air to bring more CO2.
The Earth is way too close to the starvation level for plants. 1000ppm of CO2 globally would help insure optimum growing conditions locally…. actually I would be happier with 2000ppm. If greenhouses typically use 1500ppm in a controlled setting with fans and such, then 2000 would make sure the plants in the outdoors and the wild plants and plankton too ( can’t forget about the non-crop plants) will have enough CO2 all the time.
Another key point here is that the researchers who claim that rising temperatures will cause a reduction in agricultural productivity, is that they keep making the same intellectual error over and over and over again. They assume (presume, actually) that the earth and its biosphere is a simple system – it isn’t, it’s very complex – and that it responds to a single stimulus in a singular way that does not account for natural adaptability.
We humans have proven we have a marvelous ability to adapt to changing climatic conditions, both over time and over space. After all, we and our hominid ancestors have survived the entire Quaternary with its two dozen or so glaciations and interglacial eras, and here we are!
In terms of agriculture, if the climate changes over time or space, humans adjust the crops and the techniques to grow them. For example, during the Medieval Warm Period, places as far north as Britain and “Vinland” in northeastern North America produced wine grapes … but when the Medieval Warm Period ended in 1850 or so, that production ended, and production shifted farther south in Europe. Today, the wine grape varietals that prosper with longer growing seasons, include the reds like Cabernet Sauvignon and Sangiovese and such that predominate in the warmer regions of Spain, France, and Italy … while in cooler climates with shorter growing seasons in northern Germany include many white grape varietals like Riesling and Pinot Blanc.
Other examples – Idaho is known as the “Famous Potatoes” state, but its famous Idaho Russets are grown mainly in the lower elevations of the mid-Snake River valley, because of its relatively long growing season, whereas in the upper Snake River valley, which is much higher in elevation, spud production is limited mainly to smaller “seed potatoes” that do fine with a shorter growing season.
So as climate shifts over time, as it will, humans will adapt and adjust and produce the amount of food needed to feed Earth’s population. It’s silly to think otherwise.
Uh, the Medieval Warm Period was from 950 to 1250 AD. You know, during Medieval times. The Little Ice Age ended in ~1850. Other than that mistake, good comment.
Yeah, got me there, got my dates mixed up. But my point is still the same – the UK has a very short growing season and has never been a significant wine producer, though it used to produce a lot more, relative to demand, when the climate was warmer.
Growing of wine grapes in the UK has not ended. Presently the following are grown there:
The production of wine grapes in the UK has been minimal compared to the rest of Europe.
In 2018, total UK wine production was 587 tons, ranking 83rd in the world for total production. The top 20 grape grower all exceeded 778 thousand tons of grapes – that would be 1,325 times the UK grape production. The top 10 producers averaged more than 8.4 million tons, or 14,334 times the UK grape production.
It may be above zero, but it’s nearly zero.
Wine grapes were introduced to Britain by the Romans in the first century during the Roman warming period. Zero wine grapes were produced in the UK from the onset of WW 1 to the 1960s when minimal amounts of commercial wine was produced. With the growing interests in winemaking world wide, as many as 400 vineyards were planted in the UK in the 1970s through 1980s but more than a third of them failed.
To the extent there is any wine grape industry in the UK, is is due to the little bit of warming since the middle of the 19th century and to general interest in producing wine.
Yeah, peripheral but still on-topic – if you get the chance to visit the former Roman city of Wroxeter in South Shropshire, England, do it. Small vineyard though. Wouldn’t even have catered to me. Oooops, was that my outside voice?
Going to England in July
Wroxeter now on my list
All white-wine grapes suited to shorter, cooler growing seasons. No Merlot, Cabernet Sauvignon, Pinot Noir etc. because it ain’t got THAT warm here yet!
humans did survive all that but there were no politicians then
In most food producing areas, a warmer climate means a longer growing season and more production.
Yes, but with a shorter ripening period. Comparing strawberries grown in Queensland for example are tasteless to those grown in Tasmania, which has a longer ripening period due to a cooler climate.
Same with the flavouring of wine grapes and superior tasting wine from the cooler regions.
Here in central CA, strawberries are grown both on the cooler coast and in the warmer inland. But they are of different varieties. Humans figured out how to select or modify species to the local environment long ago.
Start planting earlier and have mixed growing, so fruit trees can shade the lower plants.
You can’t grow anything in the frost so much better to have a few extra degrees and a longer growing season.
We’re only talking about 1.5°C per century -which maybe is 3-4 extra degrees for the mid-Northern areas (US, main population belt of Canada hugging the US border tightly for warmth, UK, Germany) and zip for the Equator (maybe more rain there though). So nothing extreme, plenty to take advantage of.
Separate observation. AGW negatively affecting crop yield has been an IPCC article of faith since FAR in 1990. All the papers since purporting to show it are either just future models with lots of assumptions, or data analyzed using badly flawed statistics. I took one such on since misrepresented by NRDC to Congress and after the lead author published the maize result graphically so you could see the flaw without using statistics. Covered in the Disclosure chapter of The Arts of Truth. Was also my very first post here in 2011.
Since after 30 years the article of faith hasn’t happened, the new AR6 technique is to claim that it may in the future. From climate.NASA.gov at present: “Climate change MAY affect corn and wheat yields by 2030.” Or maybe not.
These people are undoubtedly intelligent in this sense.
Hilarious, Rud. Thanks … or maybe not.
w.
NASA is one of the Deep State shills for Leftist politicians. It tries to convince people, not inform free citizens of scientific facts.
The “deep state” is Trumpian bullshit, zero basis in fact, but an article of faith amongst Trumplicans just like global warming is an article of faith amongst leftwinguts.
NASA is a great big bureaucracy like all Federal agencies, but at least they get stuff done, like sending space craft into space. Deep state ideologues, if such fantasy creature could ever exist, could not produce anything if their lives depended upon it … just like Trumplicans, by the way. They’re all just two sides of the same stupid ideologue coin.
Yep, Duane, the U.S. National Assessments prepared by the word-salad of at least 13 Federal agencies are the results of unbiased research by non-politicized Federal workers. The Assessments tell us confidently that weather extremes are increasing in the CONUS and that future extremes will be disastrous. Sure, there’s no Deep State.
Now now Duane don’t go all Russia colluuuusion like Simon did.
“NASA is a great big bureaucracy like all Federal agencies, but at least they get stuff done, like sending space craft into space.”
You obviously have not seen the latest cost projections and timetables for NASA launch capabilities versus those of the private sector actors. NASA is not remotely competitive.
If “Trumplican” is an epithet that means a supporter of competent and efficient free enterprise, then I will gladly wear your slur as a badge of honor!
Trumplican means a mindless right wing nut ideologue … no better than any leftwingnut ideologue. God save America from the extremist ideologues.
If you think Trump is a “mindless right wing nut ideologue”, you are the wingnut.
“… stupid ideologue ….”
say that as you click your heels together and spin around three times. Unless, of course, you don’t want to wake up.
Talking’ about yourself with your heel clicking jackboot stomping Heil Trump! mentality.
You’re starting to get hysterical, go wear some ladies garments to help calm down.
I don’t know why you’re getting so many dislikes Duane but I’ll take some red ink for you here. The people who could be accused of forming a deep state are incapable of tying their own shoelaces. The senile Barney Fife and that vile creature across the Bay from me. Trump does need to grow up though and deal with life’s losers. It’s not as if he can ship them all to ….. wherever. He will be the 47th President of them.
“but at least they get stuff done”
Proved yourself wrong right there, without me having to write anything, spoiled my fun.
Government is dominated by left wing, entitled, self-righteous ideologues who won’t accept any contrary bit of evidence or let the other team have a fair shot when it’s their turn to run things.
these “studies” always make headlines but they’re never interesting as they always amount to predicting millions of traffic accidents if no one uses their brakes
adaptation happens, often favorably
remember, there’s no climate on Earth that’s too hot for agriculture — there are only places that are either too dry or too cold
It more than predicting the obvious result from doing something that won’t happen.
Assuming world temps continue to warm slowly at about .15 per decade, and CO2 grows by 2 or 3 (or more) per year, then the growing season will be longer, water usage more efficient, and so crop yields will be higher.
The only thing that worries me is that it seems likely that warmer temps will help the bug population too, especially in northern areas where normally the winter keeps them down. Plus I’m sure governments will only get tighter with pesticide regulations, as they have to do something with their time.
As long as the winter temperature reaches the freezing point then it doesn’t matter if the winter temp is a couple of degrees warmer than 20 years ago. The bugs will still suffer the same.
Why would yields depend on average temperature? Other factors may influence it. In my experience, the minimum temperature is more important. Frost can kill many plants.
In the West and mid-West, Australia, Argentina, and Steppes of Europe, good crops and rainfall are synonymous.
Western Canada had a decline in cereal crop production of about 35% in 2021. This was due to a wide area drought on the prairies after years of good rains and good crops, related to the PDO. The media had already decided that “Climate Change” had caused floods in British Columbia so they didn’t mention the crop production issue next door in Alberta and Saskatchewan. But expect it to be thrown in with production shortfall numbers from the Ukraine for 2022, plotted against Mauna Loa CO2 of course.
It’s too bad all that extra BC water couldn’t have been channeled over to the prairies.
Good point Curious,
“Blackman’s Law of limiting factor states, “When a process is conditioned as to its rapidity by several separate factors, the rate of the process is limited by the pace of the ‘slowest’ factor.”
With growing plants that’s usually lack of water (high vapor pressure deficit) or CO2. If a plant has enough water and nutrients it will grow faster and bigger up to very warm temperatures. Whence the Tropics.
The Matanuska-Susitna Valley in Alaska is famous for the large vegetables that are grown there reliably. Apparently the long hours of sunlight are important for that. If the Earth continues to warm, for whatever reason, we can probably expect farming to become more important at high latitudes throughout the world.
High temperature can affect some crops – for example, my tomatoes don’t set fruit during the hottest few weeks of summer. I can mitigate this with a shade cloth, but I could see where a large field grower wouldn’t have that option. But my peppers don’t have any problems.
But that’s several sustained days well over 32C for that to be an issue. And the plants don’t die, unlike a frost. Once things cool off a bit they get right back to producing, until killed by frost.
You bring up a very good point in that there are approximately 45 commercial crops in the US that grow best in shade or indirect sunlight. By installing solar arrays over these crops, farmers amplify the commercial utility of their land and increase their revenue.
By installing solar arrays over these crops, farmers amplify the commercial utility of their land and increase their revenue.
I know I’m talking to a wall, but for the benefit of other readers:
You have obviously never operated a farm. I doubt you’ve even grown a garden.
First, a shade cloth IS TEMPORARY, you remove it when you don’t need it anymore. Can’t do that with solar panels.
Second, FULL SHADE is bad for pretty much all crops. Which is what you get under those panels.
Third, managing wide open fields is labor intensive enough. Trying to work your way through rows of solar panels is prohibitive for any scale farming.
I won’t even touch on the potential dangers to field workers.
Wrong.
Wrong to an astounding degree.
Another laughably inaccurate comment.
Which is good, because your comments have looked increasingly foolish.
Here are some references to the realities of agrovoltaics. You’ll ignore them, I’ve no doubt.
https://www.dw.com/en/farmers-reap-double-benefits-with-solar-power-in-fields/a-58284134
And…
https://www.energy.gov/eere/solar/farmers-guide-going-solar
You’ll ignore them, I’ve no doubt.
Where are the “reputable peer-reviewed journals” Barry? Didn’t see any links to any of those. Just a couple of propaganda pamphlets.
There actually wasn’t a request for specific research in your message. I assumed real-world examples of agrovoltaic systems would help you understand the errors in your claims. But, since you’re evidently not satisfied with these examples, here are some references to research involving agrovoltaics that might prove enlightening.
https://www.researchgate.net/publication/284130981_The_Potential_of_Agrivoltaic_Systems
And…
https://www.nature.com/articles/s41893-019-0364-5
And…
https://www.sciencedirect.com/science/article/pii/S0959652621032807
And…
https://www.sciencedirect.com/science/article/abs/pii/S221462962100116X
And…
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0203256
And…
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0254482
And so on, and so on. Enjoy.
TonyG is right on each and every point.
Especially working under solar panels. One of the worst efficiency penalties in working a field is having to turn around or move around an obstacle. Those solar panels need supports, they don’t just float in the air. Try and get a fertilizer sprayer or insecticide sprayer around and through something like that!
There is a difference between large, broad opaque covers, and translucent films or nets. Are you sure that the crops you refer to will tolerate opaque covers?
The crops you mention will have to be planted, weeded, and harvested by hand, as machinery would have to be custom designed, and even then may be a hazard to the high-value solar panels. Hand planting and picking will increase the cost of the products to where they many not be competitive with what is grown elsewhere with machines.
The panels will also prevent the direct receipt of rain. The dark panels get hot and interrupt the flow of cooling winds. While reducing the red-blue light necessary for photosynthesis, the plants will be bathed in thermal IR from the undersides of the panels. How will they handle the extra heat? Will it negate the ‘shade?’
Not surprisingly, there would appear to be a lot of things that you haven’t thought about before making a statement about what will happen if your advice were followed.
Read the references I provided above, please.
Against my better judgement, I actually spent the time to read the links. I’m not impressed. They talked about reductions of crop yields of 50%. It takes energy to run machines, and that costs money. So, there is a fixed cost to the machines whether the crops provide 100% or 50%. There are issues of keeping PV panels clean when they are so high that machines can pass under them. While not an insurmountable problem, the stilts necessary to elevate the panels also create obstacles for the machines, with risk of damage to the machine and the stilts. Then there is the issue that the best sites for PV farms may be poor sites for agriculture. There may be instances where a creative farmer can make a profit with dual ‘crops,’ but I doubt that it can be done universally.
You clearly didn’t read all the links, and you clearly are desperate to take comments out of context and twist them to support your original and very much wrong assertion.
Simply put, agrovoltaics is the future across many crops. And the practice will keep many family farms solvent. Don’t fear the future.
And this just in… https://www.theguardian.com/global-development/2022/feb/22/kenya-to-use-solar-panels-to-boost-crops-by-harvesting-the-sun-twice?fbclid=IwAR0NcjJXpx8WXNWnzSmwigAIJuU_v3PyKaOeiGXumzv8jf0QqiYJ-lrcx7w
With higher temps, tomatoes need more water, while more water (rain) in cooler temps are destructive to tomatoes.
My experiances.
Every “little ice age” and post volcanic eruption cooling period has been negative for humanity.
“Declines in yields and crop suitability are projected under higher temperatures, especially in tropical and semi-tropical regions.”
So many of the AGW arguments implicitly start with “with all else being equal”
The individual dots representing countries need to be scaled to each countries production tonnage.
India, China, Brazil and USA would then stand out as only as only countries worth looking into. (Maybe Also a combined EU and Russia)
Then reanalyse taking into account both crop size of average farm and $ spent ( machinery, labour and chemicals) per hectare.
Changes to economies of scale and technologies must be considered.
I once read that a single farmer in cool Sweden can produce as much food at several dozen farmers in warm India, because mechanization and fertilizers; i.e. fossil fuels.
I read an autobiography of a man who escaped North Korea after the horrible famines last century. The famines were caused by new farming techniques created by academics and party members who had never farmed or touched a hoe in their lives.
I see something similar with the IPCC and other global warming activists. They seem to have no connection to reality. Ideology rules. The facts don’t matter, what they believe matters.
The Soviet Union had the same thing happen.
No, before the new methods, they killed all the farmers.
Rice production here in Australia is a funny thing.
Farmers have large laser levelled paddies adjacent to government irrigation canals.
They have water rights to canals but have to pay.
Each year farmer can:-
Pay for water and grow rice.
Sell water rights to other farmer and not grow rice.
This clearly messes up yields statistics.
Well yes very lovely, just a shame none of the things listed are fit for human consumption but starving people can’t be too fussy
iow: Howzabout graphs of heart disease, autoimmune disease, diabetes, dementia and medical expenditure over the same period?
The 18°C changeover point/isobar/whatever line, where most rich folks live, is very simple to explain.
Folks ‘get rich’ when they don’t have to spend much money on food – thus, at latitudes beyond the 18°C isotherm are more productive food-wise.
You know where I’m going, soil erosion..
Why
Because at high latitudes (less than 18°C average temperature, the soils there are and have been regularly ploughed/turned over/replaced by ice sheets and glaciers
The dirt there is intrinsically more fertile.
At warmer latitudes below the 18°C isotherm, the dirt there is very ancient. It is barren, infertile and no amount of CO2 can do anything for it.
(Don’t cast your seed on stony ground, as per The Good Book)
Don’t worry too much about it. It’s a natural process due to the fact that CO2 dissolves in rain-drops as they fall from the sky
There basically, is the reason that rich people live where they do – because there is fertile dirt that grows ‘stuff’
The very significant problem is that at those high latitudes, the really controlling factor for food production kicks in – strength of the sunlight.
If you/me/anyone wants to make ‘quality food’. we need ‘quality sunlight’ and beyond about 45 to 50° of latitude, the sun just ain’t strong enough to make the sort of proteins and fats that we need.
Hence why we are reduced to eating the high calorie but otherwise tasteless, allergenic, irritant, carcinogenic and often flat-out toxic mush in that list of barley through wheat.
Such a diet makes us fat, lazy and stupid. and dead well before our time
Rich maybe, but how does that saying about ‘Fools and their money‘ go?
This would be all very well and good, if we had remedies for diabetes, heart disease and dementia but, Stupid People are just too dumb & lazy to work them out.
They’d much rather be ‘rich’ than healthy. As we see.
The goodness would possibly still be OK, if the lines on the spaghetti (haha) graph were sustainable.
Unfortunately, there is this graph link and as attached
At first eyeballing, nitrogen fertiliser use has gone from 15 million tonnes/yr to over 100 million tonnes per year – a factor of about six or seven.
Meanwhile as per Willis’ graphs, food production has tripled
So despite the increase in CO2 and the increase in temperature, the fert we now use is less than half as effective as it used to be.
Welcome to the World of Soil Erosion.
It is fixable, very easily fixable.
But, fat, lazy stupid people simply can’t be bothered – it’s much more fun and profitable playing on computers all day.
edit to PS
It gets much much worse because, since about 1960, World Population has only really doubled.
We really are in a lot of shit here
It is well documented through experiment (from times prior to the climate scare) that high temperature during grain fill reduces the weight of the individual grains of C3 cereals (wheat barley et al)…. and thus yield.
Chas
Link???
w.
“[At lower latitudes the dirt] is barren, infertile and no amount of CO2 can do anything for it.” Central and South America, Central Africa, India, The Philippines and other tropical places are barren and infertile? I don’t think so.
It is not as simple as just the growing temperatures. The type of soil that develops is determined by the temperature and water availability. Low-fertility soils are common in low latitudes.
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/laterite
I am no expert on climatology or agriculture …. but the farther from the equator, the longer summer days are. Supposing, for example, an equatorial farm gets 12 hours of daylight year round, while a temperate farm begins and ends with 12 hours in spring and fall, and 16 hours in the summer, for a rough average of 14 hours of daylight. Is that realistic, does it make any difference, or does the more direct and stronger equatorial sunlight make up for the fewer hours?
Pardon my ignorance if it’s a really lame question; I really don’t know.
It probably depends on the crop. I remember HUGE heads of cabbage I saw in a farmer’s market in Fairbanks, Alaska.
Probably from the Matanuska Valley, between Anchorage and Fairbanks.
One thing I have noticed from measuring boundary layer concentrations of CO2 at 19°S is that CO2 take-up is rapid after sunrise but tapers off around midday, indicating that whatever vegetation is in the upstream airflow has some sort of daily quota of photosynthesis. Does it taper off later in temperate climates? There is some indication that it may taper off a bit later in what passes for “winter” here, but that is also drier.
Martin, one thing to consider is the opposing effect of CO2 and water loss.
To increase CO2 uptake, plants need to open their pores (stomata) to take in the gas. But that increases water loss through the same stomata, so when they need to conserve water they close the stomata, which of course reduces CO2 uptake.
It’s a balancing act.
w.
Some other things to consider are the amount of water and the seasonal availability. That also affects the kinds of soils that develop and the fertility of those soils. Low-fertility lateritic soils often develop at low latitudes.
More CO2 in the air means the stomata have to open less to get the food plants need and therefore lose less water.
On the other hand, Climate Alarmism with its attack on fossil fuels can and will lead to lower standards of living and poverty, resulting in increased hunger, the very thing they are “predicting” being caused by “climate change”. The irony.
The limiting of crop yield may be attributed to higher night time
temperatures which limit the plants ability to cool down. This
may explain most of the difference between warm and cold
countries. Here are some articles that discuss this factor:
https://www.pioneer.com/us/agronomy/high-night-temps-yield.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC454199/
(I searched using “decreased grain yields higher night
temperatures” & … corn yields …”)
The first time I ever heard of this was possibly 2010/2011 when
Iowa & points east in the Corn Belt had higher temperatures &
enough rain to compensate for the heat. It was the higher night
temperatures that reduced the yield. (I don’t think Nebraska was
affected as much because it has less humidity which allows the
temperatures to drop more at night.) It turns out Pioneer Seed
was already researching this in 1971.
Higher temperatures with adequate soil moisture are no problem for maize. High temperatures (>95F) without adequate solid moisture does reduce yield. That was the statistical flaw in the study I deconstructed. They explicitly (deliberately)omitted the heat moisture cross term from their multivariate regression. Argued there was no correlation. Ignored the well established fact that corn really cares. It wasn’t heat, but drought, that produced the county by county over 30 years yield declines they attributed solely to heat.
Rud-
I do remember that the yields were lower that year than had been
initially estimated due to higher night temperatures as they thought
there had been adequate rain that year. I’m almost certain it was
2010 as Iowa State had an article from Oct 2010 discussing the
reduced yield that occurred from silk to dent. In the article, they
cite an earlier Sep 2010 article & one from Aug 2009 to support their
claims. (I have “no dog in this fight” as it’s based on their
knowledge, not mine. They could be wrong)
https://crops.extension.iastate.edu/cropnews/2010/10/reduced-2010-corn-yield-forecasts-reflect-warm-temperatures-between-silking-and
True, corn likes hot humid days. High temperature and adequate moisture is critical. Wheat is the same.
You can hear the corn grow.
Figure 3 has a crazy mix of units. It refers to temperature but shows W/m^2. I cannot fathom that relationship.
Thanks, Rick. The default units for that graph of mine are W/m2, I just forgot to specify the right units.
Fixed.
w.
“It turns out that within each group, the yields in the warmer countries are no better or worse than the yields in the cooler countries. And as a result, the claim that warming temperatures will cause widespread hunger is not supported by this analysis.“
Call me a dummy (you won’t be the first) but what do you mean by group?
Try left side/right side of the vertical dashed 18C in the figures. Works for me.
What Rud said.
w.
Eschenbach’s cons are easy to spot. A faked chart here, false equivalence there, and of course plenty of lying through omission. In this case, the latter two are on robust display. While improved irrigation and fertilization has been increasing yields for many decades, GMOs have been the primary driver of increased yields around the world for the past 20 years. Plants aren’t magically thriving by way of increased temperatures and CO2 levels, in spite of how Deniers and shills are trying to spin it.
https://allianceforscience.cornell.edu/blog/2018/02/gmo-crops-increasing-yield-20-years-progress-ahead/
Yeah?
NASA says the whole Earth is greening due to improved levels of CO2.
Sorry, I should have credited those “Deniers and Shills” at NASA.
Actually, NASA says the majority of the “greening” is due to human agriculture in India and China. You need a new trope to use as a dodge.
https://www.nasa.gov/feature/ames/human-activity-in-china-and-india-dominates-the-greening-of-earth-nasa-study-shows
It really is amazing how stupid Barry is. It was pointed out to him how this article doesn’t actually say what he wants it to say, the last time he drug out this piece of propaganda.
Barry, I don’t usually respond to your ilk. But here you have made not one, but TWO egregious errors showing your ignorance or worse.
Directly from the NASA report I referenced: “The effect stems mainly from ambitious tree planting programs in China and intensive agriculture in both countries.”
And here’s a list of the current major GMO crops in the US: https://www.fda.gov/food/agricultural-biotechnology/gmo-crops-animal-food-and-beyond
No Barry, the article you cited states that –
But you say that –
Either you don’t read or comprehend your own sources, or you aren’t very good at numbers, are you mate?
Anyway, as far as greening goes –
I’ll see your India and China, and raise you Europe, South America, Sub-Sahara Africa, North America, Oceania, Australia.
(And what about all that agriculture going on in the Arctic Circle landmasses?)
Science deniers like Barry just can’t accept the fact that rising levels of CO2 increase the rate of photosynthesis and growth in plants.
Barry isn’t interested in accepting anything. He’s told what to believe, and like a true believer, that’s all he needs.
—
As usual, Barry completely ignores the actual science.
The fact that plants grow bigger and healthier in the presence of more CO2 has been known for decades.
So much hatred, complete lack of science, no attempt to understand anything other than the paid narrative.
Definitely a climate alarmist.
The Deniers love to point to greenhouses as some proof that an overabundance of CO2 is an amazing boon for plants, while failing to mention the fact that this accelerated growth also requires unnatural levels of soil nutrients, water, and carefully controlled temperatures. Your argument represents false equivalence.
https://www.scientificamerican.com/article/correction-plants-will-not-flourish-as-the-world-warms/?fbclid=IwAR1g1WSHd-8X3OrFl5_7IhFVSWXqJdKz8O4L-cqyFpiOd-osLvaunQmnjg4
And…
https://www.theguardian.com/environment/climate-consensus-97-per-cent/2016/sep/19/new-study-undercuts-favorite-climate-myth-more-co2-is-good-for-plants?fbclid=IwAR2W0acD9c_qSVPnQXepwl2rtETAKhJVfI_Ok0UqfNim_lzCTJY_LgG9yx4
And…
“The ramifications of climate change on human health are vast: agriculture, nutrition, diets, and health as a whole are all negatively affected.” http://ebrary.ifpri.org/utils/getfile/collection/p15738coll2/id/131228/filename/131439.pdf?fbclid=IwAR2zMatvVT5sRexWbYVh7YVdcOt0CIVyBoPsZPLfF3cof96PZbFOvM68n8A
And…
https://www.scientificamerican.com/article/ask-the-experts-does-rising-co2-benefit-plants1/?fbclid=IwAR23o1Pk7Xy83CCvqmhftQADHsqIJlzY-c6gnBvDXRtQrAA5-b0qmlYn89k
Shall I continue?
A nugget of valuable agreement from a scientist quoted in one of your links Barry –
Barry Anthony March 7, 2022 3:02 pm
Barry, I was brought up in part on what in my house was called “The Captain’s Code”. “The Captain” was my great-grandfather, a riverboat captain.
Part of his code was:
Now, you’re fortunate that this isn’t the 1860s, so I don’t kill people for falsely claiming that I’m lying.
I will, however, accurately describe you as slimier than pond scum to falsely accuse me of lying. I tell the truth as best I know it, always.
Sometimes wrong, rarely uncertain, and NEVER lying—that’s me to a T.
And no, I did NOT say that plants are “magically thriving by way of increased temperatures and CO2 levels” or anything remotely like that, which is why I ask people to quote the exact words you’re discussing. That’s just the voices in your head. You should ignore them, they’re not your friends.
What I said was that farmers are good at conforming their plants and farming methods to whatever the weather throws at them, whether it’s in the developed world with irrigation and harvesters and GMOs, or in the developing world where there are few of those things.
Finally, regarding GMOs, the FAO says that there are ~ 1,370 million hectares dedicated to crops, of which only 190 million hectares are GMO crops. That’s only 14%, and it’s mostly in the developed world.
So your claim that “GMOs have been the primary driver of increased yields around the world for the past 20 years” just reveals that in your rush to stand on your tiptoes in your failed attempt to bite my ankles, you are not doing your homework …
How about you dial your hatred way down and act like, you know, a civilized human being? Is that too much to ask?
w.
PS—For those interested in more of the Captain’s Code, see Rules Of Thumb For Life …
I’m in no way surprised that your veiled threats are so clumsily couched. But I will say this, Willis: Across all the countless such threats I’ve received from the shills, frauds, and liars pushing the Denier narrative, I’ve received exactly one over the years that convinced me that physically confronting the individual responsible was warranted under self defense. That individual will never repeat such activity.
Just to be clear: We all know what you’re doing.
We’ve all seen the sophomoric attempts at pseudo science. We’ve all seen the amateurish snark, “No, I’m not a scientist, but…” We’ve all seen the charts that, as per your claim, somehow debunk the work of REAL scientists. We’ve all seen your refusal to provide all materials necessary to reproduce those charts.
We know what you’re doing.
We know that the extent of your academic and professional qualifications to critique the work of REAL climate science researchers consists of an undergrad in Psych and, if memory serves, a certificate in massage therapy. (By all means correct me if I’m wrong.) Has ANYTHING you’ve put forth on the topic ever appeared under peer review in a credible journal?
All but the most cognitively compromised participating in these threads understand these considerations, even if they refuse to admit it. Frankly, to insinuate that any scientific advocate would require any assistance at all to, “bite your ankles,” demonstrates a level of posturing that beggars the imagination. (Perhaps swimming in such a small pond as WUWT to the adulation of a handful of educationally underserved has instilled such a disturbingly inflated sense of worth?)
We know what you’re doing.
[I believe there is value in allowing your brain-dead, knuckle-draggin bile, lack of comprehension, and rabid ideological rantings on this site, but I have to admit, it’s not a slam dunk of a choice. You make it hard-cr]
Barry is a product of our time. I pointed out at an AGU dinner 10 years or so ago that everything that could be predicted about climate change has been predicted, droughts, torrential rains, earthquakes, heat, stronger storms, weaker storms, etc.. This has created a situation where no matter what happens, it is easy to search the literature and find out that the event was predicted. Therefore climate scientists are nailing it! This is exactly the logic Barry’s handlers use when feeding him his responses.
The playing field is prepared. Everything that can be predicted has been predicted. It doesn’t matter if there are a hundred years of studies pointing out enhanced growth under CO2 as well as massive amounts of current observational evidence. As long as somebody crams 2-4 studies into the literature about why CO2 enhancement might not be viable, those several studies can be cited ad infinitum to refute reality.
What Charles said …
w.
I love the “we”, as though you’ve been appointed spokes-dick for the teeming masses …
Next, you say:
Gosh, an ad hominem argument. How original.
However, you’re right about my credentials. I have no qualifications at all, details here … which makes no difference at all. The beauty of science is that either my ideas are right or not, regardless of my qualification.
Barry, they have this cool thing called “Google Scholar” which would prevent you from looking like a vindictive fool … or not, since you have to be smart enough to use it first.
Give it up. You’re up against the First Law of Holes.
w.
PS—One reason I gave up writing for the journals is that Michael Mann gamed the pal-review system to steal an idea of mine and publish it as his own … see “Michael Mann, Smooth Operator” for details.
So, just to be clear, you in fact DON’T have any research on the topic of climate science appearing under peer review in a credible journal. And yet, mysteriously, you’ve suggested your layman’s level of understanding in the field and an appearance alongside categoric frauds like Legates and Soon represents validation.
You couldn’t have done a better job supporting my argument.
The prosecution rests.
“So, just to be clear, you in fact DON’T have any research on the topic of climate science appearing under peer review in a credible journal.”
Funny how this is not a criteria for anything. Just ask Steve Jobs or Bill Gates!
False equivalence. Neither one ever attempted to push bunk while claiming they’re successfully contradicting climate scientists. Or any scientists, for that matter.
Talk about a false equivalence.
Both of these fella’s contradicted IBM, Dec, and HP’s meme that personal computers could never challenge their dominance in mainframes and mini-computers. They put out all kinds of literature stating this. Even Bell Labs didn’t get into personal computers because they didn’t think they would ever amount to anything.
Jobs and Gates *did* successfully contradict all the computer experts who stated that their work was bunk.
All you are doing here is using the argumentative fallacy of Argument by Dismissal. Poor. Very poor.
What you don’t know is, a lot of science is based on laymens knowledge and their work.
The work they did, because of interest or what ever later led to science.
Take archaeology, ichthyology, entomology and other branches.
More you are interested, deeper you dig, more you learn and know. Often more than a respective scientist nowadays.
Many scientist won’t accept it but it’s fact.
The father of my grandfatherid is an example.
He worked with stones, no idea how to name the no more existant job, but just of interest, he became specialist in night moths, puplished expertises in respective monthlies that has been founded by laymen (!).
Two species or so have got his name as he declared the one and the other as different species because of some differences in appearance, diet and behaviour.
Laymean, not scientist with degree !
Later he punlished 3 books of the research in several nothern regions, 2 of his sons were part of the team.
They later started trips and research in South-Americas rain forests, one later studied entomology.
My grandfather was to young for all that.
who in Pete’s name is “we”?
Have you gotten banned from Facebook yet for libel in your posts? Posting here isn’t going to help your cause.
You really know how to sweet talk a guy, don’t you!
If rising temperature reduces plant growth explain the tropical jungles of earth.
Lettuce doesnt do well in tbe tropics. Not because it grows slower. Rather the slugs and snails grow faster.
There is a lot more to growing crops than temperature. The great deserts of the earth are almost all the result of air circulation not temperature.
Sunlight, liquid water, these drive plant life. not temperature.
And while we are at it. Explain why a naked human without fire cannot survive outside the tropical jungles. We die of exposure.
Explain how global warming is going to kill one of the best heat adapted mamals on the planet (and one of the worst cold adapted mamals). Without fire we can barely survive outside the tropics even today.
“Naked and Afraid” doesn’t do much outside the tropics. I wonder why?
What if the rising temperatures transform our cultures so we all act tropical?
Late, I know, but tomatoes don’t set fruit much if the nighttime temperature drops below 55°F. If you have more than about 3 plants, that is hard to control.
Over 90°F in the day will also cause blossom drop, but existing growth can go on, and spray and shade can help.
I’m more inclined toward tomatoes than I am to Cassava. Just saying.
Recently I stumbled on this report:
https://news.cornell.edu/stories/2021/04/climate-change-has-cost-7-years-ag-productivity-growth
that spins the kind of yield results you show as warming actually hurting productivity.
Although the report (and the underlying paper) are worded somewhat confusingly, it appears that the work is based on the underlying assumption that productivity growth should be exponential.
The linear trends you show result in the percentage increase each year decreasing, as the “denominator” keeps increasing, while the “numerator” remains constant. They blame this decreasing trend on warming.
Yeah, I’d read that a couple months ago. I stopped about here:
They’ve combined faulty econometric models with faulty climate models to simulate an alternate universe where temperatures didn’t warm over the last six decades. Yeah, that’s totally legit.
Unfortunately, what the faulty models don’t include is … farmers. My favorite lines are:
and
So it seems if you populate a modelworld with mechanical farmers, modeled temperature could lead to modeled yield decreases …
This is why I work to draw conclusions from actual data … I know far too much about computers to trust their models.
Finally, your point is also well taken. Linear growth is a decreasing growth as a percentage.
My bottom line? I put more trust in farmers than in ivory tower modelers.
w.
According to Garland Farms plant farming is the major cause of the Climate Change
Here is a page from DeKalb showing some of the types of seed corn offered. There are other breakdowns for more detailed soil types too. Not an easy task to decide which one to use based on how and where you farm and based on weather forcasts. Simply deciding on 100 day vs 120 day maturity is a factor.
DEKALB Corn Seed Finder (dekalbasgrowdeltapine.com)
Willis et al, some years back I read a discussion on a temperature line in the Northern Hemisphere that marks the border between growing one and two crops per year. Above that the line soil is too cold to grow a second crop. The Paper then described the area that was made available from each 1*C increase in average temperature. Each 1*C increase could feed another 300-500 million people, and as you say no real decrease of loss of production in the rest of the world. Anyone see it or can reproduce it?
I suspect that the “higher temperatures give lower yields” result comes from a simple error, although I could be wrong. The obvious approach is to look at yields in some location and see if they are lower in years when temperature happens to be a little above average. Very likely they will be, since the farmers will have chosen crop varieties optimized for their current environment. That tells us nothing about what happens to yields when average temperature rises slowly enough for farmers to adjust crop variety (and other variables) to the new conditions.
There is a very simple test of whether that is what is happening. In years when temperature is a little below average, is yield higher or lower? If yield decreases with increasing temperature it should be higher. If yield decreases with deviation from the average the farmer is adjust to, it should be lower.
Have any of the people claiming that yields fall with increasing temperature published enough of their results so one can tell?