Iowa Agriculture in consideration of climate change

Average annual precipitation in Iowa 1981-2010. Note the 50% gradient northwest to southeast across the state. Figure from reference [3].

Average annual precipitation in Iowa 1981-2010. Note the 50% gradient northwest to southeast across the state. Figure from reference [3].

By Kevin Kilty

A recent article in Physics Today[1] presents use of regional climate modeling in forecasting how climate change might impact agriculture in the U.S. Midwest. This guest blog offers a summary of this effort, and makes additional observations.

Introduction

The introduction makes a case that Iowa is a proxy for the Midwest itself, and that agricultural productivity in the Midwest is very important to the national and global food supply. It is clear that climate conditions in Iowa have improved markedly for selected crops since the 1980’s. One may find supporting evidence in the changing agricultural practices of farmers. However, the authors argue that this present “Goldilocks” period cannot last, and that by mid-21st century climate change could decrease Midwest agricultural productivity back to 1980s levels. This dire warning comes by way of the Fourth National Climate Assessment made in 2018. David Middleton has poked fun at this assessment.

What factors have led to the increases in Iowa productivity since 1980? The authors note sophisticated/automated machinery, the use of large amounts of fertilizer and pesticides, improvement in hybrid crops, and crop diversity reduced down to the two most favorable crops, corn (maize) and soybeans. In addition, growing season climate has become more favorable. Humidity, in particular, has become higher, which reduces crop stress for water, but it has not become so high as to encourage fungus and molds. Also, there has been abundant sunshine and higher temperatures, but not so high as to limit crop growth or production.

Right here the paper runs into its first contradiction, for within the next few sentences the authors say:

“…higher humidity, overcast skies,… and wet soil have decreased the fraction of solar radiation converted to sensible heat as opposed to latent heat….which has led to a so-called warming hole in the central U.S.”[2]

So, did climate change lead to productivity increases, or not? Was there more sunshine or not? Note also that there is no mention in this introduction that increased CO2 itself may have led to some portion of the productivity change between 1980 and now.

Agriculture and climate

One of the most valuable contributions of this paper is its extended discussion of the constraints that agriculture operates under with regard to rainfall, and temperature impact on crop germination, growth and pollination. Most people do not realize that these constraints exist. Figure 1 in the paper, in particular, a Decision Calendar, illustrates the situation very well.

Another valuable contribution is an extensive sidebar explaining the specific climatology of the Midwest in the April through June time period, and how climate change might affect this.

Projected trends

Figure 2 in the paper shows future projected trends for rainfall in North Central Iowa, and is rather unconvincing. First, in view of the authors’ statement that models project a rise in extreme rainfall that will level off in the mid-21st century at a “value 2.5 times that of the almost-constant 20th century” (emphasis is mine), Figure 2, which is central to this argument, doesn’t show the whole 20th century, but only its final 40 years. This truncation is odd considering there are at least nine documented NOAA hourly or daily precipitation stations in the Cedar River Basin alone whose records predate 1960. Four of these stations go back to the 1890s.[3] Moreover, the figure compares observations, which ends at year 2010,[4] with 10 and 90 percentile limits on the projections. These are weak limits — they only exclude 20% rather than 10%, or 5%, which are more customary. The observations, while rising, do not level off at 2.5 times the 1960-2000 period, and jump to the 90th percentile very quickly – another case of observations not adhering to models. Why use the 90th percentile as a basis for extreme rainfall, rather than the average or expected annual maximum daily precipitation? Finally, the 10 percentile projected limit inexplicably goes to zero, drops literally off the chart between 2080 and 2090. Why? Perhaps this paper could have made a stronger case, and needed a more thorough peer-review, but this figure and its companion discussion is messy.

Adapting and coping

How might Iowa agriculture, and by extension U.S. agriculture, cope with a world that warms, provides different precipitation, and changes the timing of agriculturally important climatic events? The paper discusses two responses. First are changes in agricultural practice. Iowa farmers, in their understandable zest for chasing profits have reduced agricultural diversity. Reverting to some earlier practices, especially reducing monoculture over large fields is one such response the authors propose. Another suggestion is restore some of the one-half of soil carbon that has been lost through deep tillage since Iowa was tall-grass prairie, by plowing in biochar. Biochar resists decomposition, supports healthy microbial populations, and improves soil’s water handling capacity. On the positive side, assuming that CO2 truly needs to be sequestered, biochar permanently sequesters carbon, and is readily available for production from crop residue locally throughout the Midwest. Yet, what is the likely cost of this? A 2007 study [5] suggested that biochar might be produced from grain-crop stover for $9-$16 per ton (2007 prices, probably more like $12-$20 now), but this did not include the labor or energy or equipment to return the biochar to a field and plow it back in. Quantities like ten tons per acre are suggested as reasonable treatments, which sounds like a lot of expense.

Conclusion

Certainly, it is true that agriculture, mundane and out of most people’s minds, but in fact complicated to manage, is very dependent on climate. This makes any impact from climate changes a genuine concern. Yet, I found the inconsistent stance in certainty in this paper grating. Mixed with cautious statements of future trends using words like “likely, may, could,” are absolutely certain statements about the future like:

“Elevated atmospheric CO2 can have a fertilizing effect that will partially, but not entirely, offset crop-yield declines caused by climate extremes…”(p. 30)

Or,

“…enhanced Gulf (Mexico) temperatures and a strengthened Great Plains Low Level Jet that we have traced to global climate change from increase greenhouse gas concentration have created significant problems for Iowa’s agriculture…”(p.31)

Often I feel as though climate change and related phenomena are simply axiomatically true, and one need only express caution about the timing and magnitude of future bad things, but bad things for sure.

While the article summary makes its usual call for increased research funding to help maintain agricultural production in the current half of this century, the authors’ reliance on unproven projections of future temperature are not especially convincing. Recent work, often summarized here on WUWT, suggest CO2 emissions scenarios and model-based temperatures are over estimated, possibly quite badly, which in turn makes predictions made even a few years ago suspect. The interested reader may find a few of these here, here, here, and here. The estimates of maximum temperature increases shown in Figure 3 are so large (up to 11F by 2100) that one might wonder if the authors confused RCP8.5 with some far more reasonable projection as many people seem to do.

The truest statement in the paper, and a valuable take-away, may be this:

“Spatially inhomogeneous heating caused by the different radiation absorptivities of land, water, vegetation, and ice creates a complex climate that defies simplistic predictions of how future seasons will play out at any fixed point.”(p.32)

This seems obvious for temperature, and must be doubly so for precipitation, flooding, humidity and a range of other important climate measures.

Notes:

[1]Eugene S. Takle, and William J. Gutkowski, Jr., Iowa’s Agriculture, Physics Today, February 2020, Vol 73, No. 2, pp 26-33.

[2]- Z. Pan et al., Geophys. Res. Letters, 31, L17109, (2004).

[3]-C. Maxwell Stanley, 2014, Hydrologic Assessment of the Upper Cedar River Watershed, University of Iowa, Iowa Flood Center. This paper also contains an interesting table of alterations to agricultural practices sine 1820.

[4]Probably what explains 2010 end of the observational data is it being not updated from earlier research of one of the authors (See for example, Takle, E.S. “Was Climate Change Involved?” Chapter in A Watershed Year: Anatomy of the Iowa Floods of 2008, C. Mutel (editor), University of Iowa Press, Iowa City, IA, 111-116, 2010.)

[5]John L. Gaunt, Johannes Lehmann, Energy Balance and Emissions Associated with Biochar Sequestration and Pyrolysis Bioenergy Production, Environmental Science and Technology,2008, 42, 4152–4158.

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66 thoughts on “Iowa Agriculture in consideration of climate change

  1. The biochar comment is interesting. The suggestion is that biochar be applied at 10 tons/acre. However, biochar would be obtained from corn stover by pyrolysis. However, corn stover is only available at 3.5 to 4 tons/acre (www.agry.purdue.edu/ext/corn/pubs/agry9509.htm) and pyrolysis of stover to biochar would probably reduce the yield to well below 1 ton/acre as stover is only 48% carbon to begin with. So where will all this extra biochar come from?
    Current practice is to plow stover back into the ground to return some nutrients. DOE claims only 1/2 needs to be returned to the ground and the rest can be converted into ethanol via Cellulosic Ethanol processes. Unfortunately, all CE processes have failed including the large scale plant built by Dow Chemical in Nevada, IA which closed several years ago.
    It seems that farmers already know how to manage their acreage to produce the most yield and revenue, so why do academics that have not farmed think they know better?
    And then there are politicians that think farming is a very simple task. Put a seed in the ground and watch it grow. Farming is far more complex than that, unfortunately. But remember, the entire Midwest is stupid per one Presidential candidate.

    • “the entire Midwest is stupid per one Presidential candidate.” would be a reference to Mikey Bloomberg. How did this guy make billions of dollars? How will he respond to the attack by Warren where she calls him out for describing women as “horse-faced lesbians”? The bread-basket of America is an under-appreciated advantage we have over the rest of the world.

      • Bloomberg became very wealthy providing a financial service people found valuable and worth paying for. He also gainfully employed thousands in the process. Now that he has been shown to be an incompetent politician, a large chuck of that wealth has been spent with no return. He’ll probably respond by throwing more money away. The easiest person to fool is yourself. Other people not so much.

      • FUTURE BAD THINGS…
        There will definitely be future bad things like Flooding, Drought, High Winds, Early/Late Snows, Early/Late Springs, Early/Late planting seasons, Tornados, Hurricanes, (and Shark-nados and Piranha-canes). Much like the bad things happening today as well as those bad things that happened Yesteryear.
        Man cannot control the whimsy of Weather

      • “…the attack by Warren where she calls him out for describing women as “horse-faced lesbians”
        Only one . Rosie .
        😉

    • Would one not release more CO2 (from energy consumption) to make the Biochar than one would sequester from it?

    • Dr Bob,
      When you run out of affordable biochar, simply grind up coal and plough it in. The effect on the farm soil is quite similar. The effect on the logic of greenhouse abatement is to show stupidity – for both the biochar and coal proposals.
      If extra carbon in soil is deemed good for agriculture, that carbon has to participate and so it gets used up over time. In most cases, using it up leads to more atmospheric CO2, the end product of many natural, man-made and academic thought processes. How awkward for dreamers! Geoff S

  2. As the little warming we have seen in the U.S. in the last hundred years (about 0.6ºC) has been almost all warmer nights, we should expect more growth during night-times and better crops. The authors have not really looked as the but simply accepted the propaganda that we are warming

    • The charts show no evidence of global warming up till now, however things are going to get catastrophic soon. The models have spoken.

    • Most of the warming in this region has been in the winter. There’s been no increase in the average summer highs and maybe a slight decrease. They might have figured that out if they had talked to some people who actually live in Iowa.

    • Actually the data shows a net cooling in the United states over the last 100 years, certainly the last 90. The .6° is global estimate.

      • Last year’s annual average temperature is actually lower than the equivalent in 1900 – 119 years ago – according to NOAA. Too many people are fooled by anomoly graphs.

    • CH,
      But sunlight is a major input for growth. Perhaps you can invoke the logic of greenhouse gas warming theorists and proclaim as fact that more CO2 might not add to yields at night, but it slows the loss of yields.

      • What makes you think that grains like corn and soybeans don’t grow at night? Even the lowly dandelion will show large growth overnight after being mowed off in a lawn.

  3. GCMs are bad enough. Continental worse. Regional even worse. Down to the state level? Utter joke.

    • Even the modelers say that anything below global scale is worthless.

      Climate science, the only field of human endeavor where averaging a whole bunch of wrong answers results in good data.

      • …and it’s models all the way down

        that’s the reason there’s so many contradictions….the models really are crap and can predict anything

      • An actual experience years ago. When introduced to a software cost estimation tool a manager said “this is great, I can get any answer I want!” Times change but people with an agenda don’t.

  4. #1 crop in the US is corn and a large percent it is used for ethanol. My personal experience
    with E10 & E15 fuel has not been favorable. I had several equipment failures in
    small engines that were expensive to repair and now exclusively use premium non-ethanol
    fuel for all small engines. I also found that in automotive use my mileage with E15 fuel
    was aprox 15% lower than fuel from a non ethanol source. This program in my view needs
    to be abolished, but it won’t because of the corrupt nature of our government It looks
    like the E fuel program is a branch of the climate change tribe to me.

    • We all suffer from the fact that Iowa has the first presidential caucuses/primaries in the nation, so politicians bend over backwards to push corn/ethanol subsidies and such nonsense. But, let’s hope the Iowans are better at agriculture than they are at counting votes.

      • Severian, you won’t find an over-abundance of Democrats in the farming communities. The people good at agriculture are mostly conservative.

        • They have to be. Most of the facts in life pertaining to agriculture are conservative. Too much “innovation” in crops and practice, and one goes broke. At the same time there has to be enough flexibility to adapt to changing markets and conditions. It’s a balancing act — which always demands conservatism.

  5. Got to give them credit for one thing.
    This is the first paper I’ve seen that actually acknowledges that farmers are capable of changing their practices as conditions change.
    Most just assume that farmers will keep doing what they’ve always done until the bottom falls out.

    • That’s a great channel – I’d like to introduce him to Bloomberg, who thinks farming is just about putting a seed in the ground and watering it. Better yet, have Bloomberg spend a day with him. He wouldn’t last an hour. Cole is an incredibly industrious young man. I just watched him dismantle the heads on a combine Thursday night to replace a bent shaft. He’d never done it before.

  6. “First, in view of the authors’ statement that models project a rise in extreme rainfall that will level off in the mid-21st century at a “value 2.5 times that of the almost-constant 20th century” (emphasis is mine),”

    Figure 2, which is central to this argument, doesn’t show the whole 20th century, but only its final 40 years.”

    Youngsters use specious “Fourth National Climate Assessment” claims to ‘model’ weather for a climatically minimal period in Iowa!?

    I am curious, did these armchair farmers mention irrigation anywhere?
    Iowa is no stranger to droughts or floods. Yet these weather and climatic events appear to be smoothed away.

    Researcher assumptions put Iowa as exemplifying North America’s Midwest; yet nowhere are weather/climate trends for the entire Midwest examined.
    First they isolate Iowa, then they intimate their doom pronunciations for Iowa will impact the entire Midwest. An indication, that is, that these researchers decided their results before designing and building their research.

    North American farming practices coupled with improved hybrid crops have increased yields dramatically. Yet, these researchers claim that our current period is a “Goldilocks” doomed to degrade over time?
    • It isn’t the crops. Crops easily handle the slight temperature changes.
    • It isn’t the types of crops. Crop varieties have vastly improved in vigor, yield, consistency and quality.
    • It isn’t farming practices. USDA and state extension services constantly apply real science and extensive testing.
    • It is not likely to be rainfall; as rain is augmented by irrigation. Floods tend to be very temporary.
    • It isn’t the temperatures as the crops grown are well within their preferred temperature profiles.

    Then there is their sudden insistence for a cure-all of biochar…?
    Black soil or Terra Preta is an excellent soil augmentation for anywhere.
    Living in an extremely high clay area, I’ve added biochar to my soils trying to improve the soil for my garden. However, I do not have the means to till 4′ to 6′ deep to break up the clay mass. Meaning my carrots look like bent and smashed nails.

    • No test Iowa plots.
    • No extensive attempts to improve the soil via biochar.
    • No efforts to estimate immediate impacts to farmer earnings.

    One gets the idea that their alleged research is just more religious babbling.
    Coupled with an inner belief that some tyrannical government despot will dictate their modeled farm world to all of Iowa and the Midwest; thus saving the world…
    Well, at least they already know how to code.

    • The academic farmers in this case, a meteorologist and an agronomist, stated that Iowa does not irrigate much but is naturally wet enough to support corn and soybeans.

      I actually grew up farming some and owned an integrated farming/cow-calf operation in the high plains way west of Iowa. We did irrigate, and the warmest year I can recall, 1988, was bumper crops.

      Over my lifetime of connection to our local agriculture we have had, wet cold springs making planting difficult, late freezes that caused replanting to different crops, blazing hot spells in summer where everyone expressed worry about pollination, hail storms that took corn of sugar beets right to the soil, early frosts, early blizzards, wet autumns making harvest difficult, and so forth an so on. Successful agriculture is having lots of back-up plans and flexibility. There is no Goldilocks climate that I am aware of.

    • Some long time ago I purchased a particular home based on the fact that, for what I could afford, it had a sizeable yard. I wanted to garden. The yard, it turned out, was clay.

      Being in California, there was no rain there for most of the warm part of the year. When the soil was dry, as it was the first time I tried anything with it, I couldn’t get through it with a pick axe. That is one of those two headed tools, one side of which is basically a heavy spike. The soil seemed almost like solid rock.

      I tried soaking an area first. It was then so sticky that, while I could force a shovel blade in most of the way, none of what came out on the shovel (very heavy stuff) could be shook or pitched off. It had to be scraped off.

      I started applying compost. I divided the yard into plots and treated only the plots, leaving the paths between and around them mostly untouched. I made compost piles frequently with whatever I could get. Much of it was sweepings from horse riding stables not many miles away. Most of the finished compost went on top of the soil as mulch but as the soil improved it became easier to dig in a little compost when I planted new seed or seedlings. Also, the mulch seemed to decompose itself into the soil pretty well. Crops were soon good.

      In the eleventh year we decided to move. I was too busy to give the garden any attention that spring and summer. Nothing was planted, nothing was watered. Shortly before I left for the last time, while giving things a last once over to assure myself I wasn’t forgetting anything I would regret, out of curiosity I dug into one of the plots with my hand. It was completely dry but I was easily able to bury my hand and arm, straight down, to the elbow.

      I understand that kind of practice might not be economically feasible on commercial acreage but carrots (and every other crop I planted) like that kind of soil.

      • See http://www.charlesdowding.co.uk for a lot of detail on no-dig vegetable growing using surface dressings of compost. A lot of very useful information for anyone interested in growing vegetables in their backyard with very impressive results.
        I don’t know whether the method could be adapted for large scale corn and soybean growing as the amount of compost would need to be very large, although min-till systems seem to be part of the way there.

  7. I assume that there are some USCRN monitoring stations in rural Iowa. It would be interesting to see the trends, if any, in their records.

  8. Since the polar vortex is so strong this year and is forecast to continue on a high note, this raises uncertainties for the upcoming spring, as the final warming could have an unpredictable influence, affecting the weather patterns even into late spring and early summer. The graphics below, show the ensemble forecast for the strength of the polar jet stream and the polar vortex, keeping it abnormally strong well into spring.
    https://www.severe-weather.eu/wp-content/gallery/andrej-news/1_latest_u1060_ens-1.png
    https://www.severe-weather.eu/global-weather/lower-stratosphere-cold-vortex-ozone-spring-fa/?fbclid=IwAR2V7bODtxsyz-YLGsaBnEU8rV-Mj5CBrL8Y9OA2ALjBeUPNkDCf5e2hMBk

  9. Just give up, the end i neigh !
    “The human race could cease to exist without massive worldwide action to tackle global warming, economists at JP Morgan have warned in a hard-hitting report on the “catastrophic” potential of climate change.”

    • Nigh.
      These economists are calling on world governments to introduce a global carbon tax to prevent impeding “global meltdown”. Presumably the JP Morgan economists would be willing to be a major force of an orderly market for the ‘carbon sin indulgences’ in order to save human race from self a destruction.

    • On the other hand “Austria, Denmark, the Netherlands and Sweden REFUSE to pay for one trillion euro plan to help fight climate change”
      Obviously they are not entirely convinced by the JP Morgan economists’ “global meltdown” prophecy.

  10. “n extreme rainfall that will level off in the mid-21st century at a “value 2.5 times that of the almost-constant 20th century”
    Most of the water that reaches the midwest comes from the gulf of Mexico via the jet stream from what I read. So increasing it by this much means gulf SST must increase a lot or something must change the jet stream. As I’ve pointed out many times air has a puny amount of heat compared to water. You would need very high air temperatures to heat the gulf surfaces temperatures much. What am I missing?

    • The claim in this paper is that the Gulf is already warm, and that warmth is the result of climate change. I made a cursory effort to find evidence, but at most the Gulf seems to be about .25F warmer than baseline. I have no idea if that is sufficient to explain the “climate change” claim they make, but there are some other oddities in the paper.

      First, most of the evidence for bad stuff happening is, by climatology standards, pretty old work — circa 2005.

      Second, the “climate change” to this point from the 1970s has produced a current “Goldilocks” climate, but of course with climate change the future will be bad. It seems to be an instance of a “just so” argument.

      • Do they have a margin of error for that number? It’s mighty small to be making that kind of assertion. There is considerable sst variation across the gulf when you consider the very warm loop current and its spun off eddies

        • I don’t know who “they” you are referring to is, but the authors of the paper never stated any temperature for the Gulf. The figure of 0.25F I gleaned from a Bob Tisdale guest blog some time back…there was no margin of error for that number, and you are correct that the North Atlantic general circulation removes water from the Gulf and transports it to high latitudes.

  11. I now fear that alarmists’ prophylactic measures will do much more harm to human civilization than will any incremental climate change. But that WAS the intent of the neo-Malthusian Club of Rome, wasn’t it?

  12. The historical records during the 2 previous Warm Periods (Roman and Midieval) are sparse regarding crop yields…but those Civilizations were dependent on agriculture and they flourished during those warm periods. Civilizations decline and fail during cold periods…when droughts are more likely: https://wattsupwiththat.com/2019/04/04/the-little-ice-age-back-to-the-future/

    There is no basis for any certainty that agriculture will suffer with another degree of warming (assuming we ever see another degree of warming). Extremes are the bane of plant growth and so far the small increases in Global Average Temperatures have not been associated with extreme heat…the opposite is true…at least in the US:
    https://realclimatescience.com/2019/03/decline-in-intensity-and-frequency-of-hot-weather-in-the-us/

    Same goes for drought: https://realclimatescience.com/2019/03/us-drought-near-historic-lows/

    These fraudsters are all funded by the government. Heck, since Climate Science is settled why do we continue to fund these Activists?

  13. Kevin
    You remarked, “…, agriculture, mundane and out of most people’s minds, …” That is because farming is so easy that even Bloomberg could teach anyone how to do it.

    • Clyde Spencer: A hay hauler I knew well and I were speaking of how easy agriculture was as we loaded a semi. He said “When I drive down the road people must say to themselves, now there goes a simply guy with a real simple job.”

      “all jobs look easy until you have to pay the bills.”

      Bloomberg says, and thinks, a lot of stupid stuff about things were he has never had any responsibility.

    • Clyde and Kevin,
      The problem is the democrats contempt for farmers and their ignorance of the complexities of modern farming. Farmers represent just 2% of the potential voter base and about a third of farmers will vote democrat no matter what, even if it turns out to be billionaire Bloomberg … or any of the other old yellow dog candidates with a ‘D’ in front of their name. In the calculus of democrat politics, the farmer votes are negligible, not worth attention, and can be openly treated with contempt.

      As for billionaire Bloomberg’s profoundly stupid remarks, some 64 years ago Dwight Eisenhower observed “You know, farming looks mighty easy when your plow is a pencil, and you’re a thousand miles from the corn field…” ‘Nuff said.

      • Let’s hope this 1/3 of farmers you mention come to see that the current Social Justice Warrior Democrats are not the same party that they used to count on.

  14. This article focuses on comparisons to 1980 and the 1980s as a baseline, as if that decade was somehow the Dark Ages of Iowa corn production (corn being the largest cash crop in the state, which is the world’s largest producer thereof). But when you look at the actual historical data of corn production per acre, the production in 1980 (118 bushels per acre), while dipping a bit from the prior peak of 1978 (123 bpa), was still well above the average yield in all prior decades going back to the early 1860s (about 36 bpa). Meaning 1980 production was well above the average of the 1970s (approx. 102 bpa), 1960s (about 90 bpa), 1950s (about 55 bpa), etc. etc. etc.

    The historical trend has been a very solid with steady decadal growth in production ever since the late 1930s when farm mechanization (i.e., use of mechanical tractors, combines, etc.) came into widespread use. With of course significant variations from year to year due to “weather” – not climate change.

    If we accept that the period from the late 1930s to the late 1970s was a relatively “cool” period, and the 1980s and 1990s were a relatively warm period … and that the 2000s and 2010s represent a relatively stable temperature period … then the data so not show any significant correlation between corn production per acre and average annual temperature at all. I haven’t run a full regression analysis, but it is obvious that the R factor of corn yield to average annual temperature must be very small.

    What is certain to be the principal reason for the mostly steady increase, decade by decade, in corn production in Iowa since the late 1930s are five key developments in the corn farming business (really applicable to all types of agriculture in the developed world over the last 85 years):

    1) Mechanization of farming

    2) More effective pest and disease management tools and techniques

    3) Changes in field management and soil conservation methods

    4) Improvements in hybrid corn varieties

    5) Improved knowledge and better data as used by more highly educated farmers

    Will all of these factors continue to create a similar effect in the coming decades? Perhaps, perhaps not. But so far the trend in steadily increasing crop yields in Iowa has continued for the last two decades just as it did for the prior six decades, so there is little reason to predict otherwise in the next two or three decades.

    • The name on that graph is “Environment and climate Change Canada”
      It illustrate very well the thinking of our Moronic prime Minister. He has drunk the KoolAid !
      He is showing his stupidity right now with his inaction with a few old indian former chiefs that are blocking
      all railroads in Canada.
      Climate Barbie was in charge of that lunatic bunch. But, hey, you have to fight that dangerous warming !
      Temp was -30 C this morning in Québec.

  15. Biochar seems to be the latest in green gardening fashions, as indicated by my brother working on a furnace to make it. I expect to see little plastic bags of it soon at high prices in the local gardening centres.

  16. “…higher humidity, overcast skies,… and wet soil have decreased the fraction of solar radiation converted to sensible heat as opposed to latent heat….which has led to a so-called warming hole in the central U.S.”[2]

    A warming hole in central U.S.? Wow.

    That could explain where those dead baseball players are coming from!

  17. Could someone explain the way the rivers are drawn on the map. I’m no expert in geography but where on god’s green earth does a river make a complete loop back towards itself.
    Iowa must be a special place indeed complete with magic rivers.

  18. If climate change has had an effect on Iowa crops, it would have to be our shorter summers, lol. The last 10 years we’ve had October snows a number of times, the last one being the heaviest. The May snow and late frosts had everyone replanting. And I do mean EVERYONE. Some places received a foot of snow that year. Other years have still been cold in the spring. In spite of shorter summers, we keep having record crops in NW Iowa.

    • When we were frozen in mid-june one year, we could replant corn with Pinto beans. Getting frozen or hailed-out late in the summer and one has zero options left. However, do note that you and I are speaking of risks determined by cold weather, not excessive heat.

  19. Iowa is far from being a propitious place to gauge the effects of secular climate change upon agriculture. As shown by numerous, vetted small-town records there, the century-long temperature trend is essentially flat. And that generally holds throughout the central plains.

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