Overall, climate change could make it more difficult to grow crops, raise animals, and catch fish in the same ways and same places as we have done in the past.
Not exactly a correction, but rather than the average temperature, the varieties of maize at least (I was in the crossbreeding are of that industry for a couple of decades), the measure to choose varieties is Growing-Degree Days. For each type of crop it is first based on base minimum temperature at which we can expect growth to occur. For maize it is usually either 50 or 55 degrees (based on some other considerations). But it also, for maize, tops out at about 100 degrees (all F). That is between 50 and 100 F maize grows more at higher temperatures until you reach 100 F. Beyond that you get no extra benefit.
The number of GDD needed for a crop to reach maturity is then based on the average temperature of each day when the low for the day is above 50F. Back in the 1960s or so we might say a maize variety was a 100-day corn. That roughly meant you needed at least 100 days in which the low temp was above 50 and the high was less than 100 (although 80 was a probable more likely high for any of the days). By the mid-1970s we had pretty totally switched to GDD. And that basically ignored water, fertilizer, herbicide, etc inputs. In other words, if an average farmer had average inputs he could expect full development (black line in the kernels for maize) of his maize when the total of the GDD equalled the GDD rating of the corn. A 2000 GDD corn was an "early" variety suitable for growing in maybe Minnesota. A 2800 GDD was a "full-season" variety that was planted in the further south regions.
Thus, maize varieties are tested and marketed today in GDDs. To the extent that the days get warmer in the north, farmers just switch (gradually) to a variety that takes more GDD. That id because, roughly, higher GDD means higher yield.
I'm reasonably sure it is the same for other plants. Farmers don't have to experiment much. They just make normal decisions based on the info provided by the hybrid seed production companies.
Obviously tillage practice come into play too. One thing many seem to miss is that the tillage practices for maize or wheat are vastly different from the practices for vegetables.
I could go on even longer, but then I'd have to start bashing agricultural ignoramuses like former Mayor Bloomberg, who I'm not sure could tell maize from pumpkins at 20 yards.
Excellent piece, as usual. I'm puzzled by the first set of graphs. Five out of six make sense, but why is it that for "Maize in tropical regions", adaptation leads to a lower yield? That seems like the opposite of adaptation. Am I missing something?
Adaptation can't lead to a lower yield, since what it means is optimizing the farmer's decisions against the new environment, which has to produce at least as high a yield as keeping the decisions the same when the environment changes. So presumably it means that there was something wrong with whatever procedure they used to estimate the effect of adaptation in that case.
Probably. It has been a while since I was in the business, but the benefit of warmer temperatures tops put for maize at around 100F. And above 80F, in the absence of good irrigation maize leaves begin to 'roll' up into tubes in order to prevent loss of moisture. The rolling then presents the former bottom of the leaves to the sunlight instead of the former top, and this in turn reduces the transformation of sunlight to grain.
It is actually fairly difficult to raise maize in a truly tropical climate (sorghum, a relative, does much better) due to the rolling in the heat problem. And the original maize (teosinte) was a subtropical to temperate plant. More temperate than not.
So, for maize, hotter is better as you move towards the poles, but not as you move too much farther towards the equator. Of course, elevation and such can have an effect as well.
Considering what crops are grown where is, in large part, determined by what subsidies the government provides, my guess is that it will be a huge mess with rising temperatures, at least in that respect. I.e. it will continue to be profitable to grow crops in certain areas despite changes in growing seasons. Of course, this is just another reason the government should get out of the business of subsidizing growing certain crops.
"Adaptation can't lead to a lower yield" -- yes, that was my thought. Since the creators of the graph must have made a serious mistake (getting the sign wrong), it makes me wonder about the reliability of the other charts.
Another adaptation is the switching of what foods are eaten in what quantities. If food in general becomes more available, people switch from carbs/grains to more expensive beans or meat. The issue of reduced nutrient content in grains is not much of a problem when beans or meat become more available.
It was over a decade ago, and I simply can't find it now, but there was a New Scientist article that stated in passing that yields in the central part of the US were up more than 10% because of CO2 fertilization and extended growing seasons. If it had been the reverse -- down >10% -- it would have been the lead story everywhere.
I find Elizabeth Kolbert to be particularly disingenuous in this regard.
I have been wondering how polar shifting affects everything. I'm under the impression, it has been shifting a lot in recent history, from the charting I saw. If the pole has shifted "x" distance, it would be interesting to see how much it would move a certain place, say near the equator or halfway between the pole and the equator. I'm in the Subtropic zone in So. Florida which makes it a very interesting study, as I've read the Temperate zone starts near Orlando, only a couple of hours north with major differences in flora and growing zones. I've personally not noticed much difference in temperatures down here and the flooding is not unusual, as much of So. Florida was dredged into existence. The Port of Miami docks and ground under all the buildings and equipment, as an example, did not exist until the Army Corp of Engineers and private developers started digging up Florida. Many of our seawalls require constant refilling of soil, to be replace behind them, as it is constantly being washed back into the waterways. especially along the Intracoastal Waterway, Ocean and Key Biscayne. As a kid in Ft. Lauderdale, I could dig down less then 3 ft. and hit the water table in my backyard, and I was 4 or 5 miles, as the bird flies, from the ocean. I always just assumed, perhaps erroneously, that the shifting deserts were also partly caused by polar shifting, in addition to continental shifting and other factors.
All this info brings up a major question on temperature modeling and I just don't believe the models can take all these factors into account and provide a meaningful result. Maybe the folks at the U.N., WEF and Joe Biden, are smarter than all the scientists who have raised similar concerns that are ignored by the MSM. We better start pushing back harder before the totalitarian oppression gets worse. Was the plandemic a trial run?
I recall reading some time ago that much of the increase in average temperatures recorded comes not from an increase in daytime temps but increased nighttime temps. If that is true, it leads me to think
The changes might have even less of an effect on plants as it simply lowers the variability of their daily temperature range. Then again, maybe some plants do need a bigger swing in temperature for some reason I am unaware of.
Not exactly a correction, but rather than the average temperature, the varieties of maize at least (I was in the crossbreeding are of that industry for a couple of decades), the measure to choose varieties is Growing-Degree Days. For each type of crop it is first based on base minimum temperature at which we can expect growth to occur. For maize it is usually either 50 or 55 degrees (based on some other considerations). But it also, for maize, tops out at about 100 degrees (all F). That is between 50 and 100 F maize grows more at higher temperatures until you reach 100 F. Beyond that you get no extra benefit.
The number of GDD needed for a crop to reach maturity is then based on the average temperature of each day when the low for the day is above 50F. Back in the 1960s or so we might say a maize variety was a 100-day corn. That roughly meant you needed at least 100 days in which the low temp was above 50 and the high was less than 100 (although 80 was a probable more likely high for any of the days). By the mid-1970s we had pretty totally switched to GDD. And that basically ignored water, fertilizer, herbicide, etc inputs. In other words, if an average farmer had average inputs he could expect full development (black line in the kernels for maize) of his maize when the total of the GDD equalled the GDD rating of the corn. A 2000 GDD corn was an "early" variety suitable for growing in maybe Minnesota. A 2800 GDD was a "full-season" variety that was planted in the further south regions.
Thus, maize varieties are tested and marketed today in GDDs. To the extent that the days get warmer in the north, farmers just switch (gradually) to a variety that takes more GDD. That id because, roughly, higher GDD means higher yield.
I'm reasonably sure it is the same for other plants. Farmers don't have to experiment much. They just make normal decisions based on the info provided by the hybrid seed production companies.
Obviously tillage practice come into play too. One thing many seem to miss is that the tillage practices for maize or wheat are vastly different from the practices for vegetables.
I could go on even longer, but then I'd have to start bashing agricultural ignoramuses like former Mayor Bloomberg, who I'm not sure could tell maize from pumpkins at 20 yards.
Excellent piece, as usual. I'm puzzled by the first set of graphs. Five out of six make sense, but why is it that for "Maize in tropical regions", adaptation leads to a lower yield? That seems like the opposite of adaptation. Am I missing something?
Adaptation can't lead to a lower yield, since what it means is optimizing the farmer's decisions against the new environment, which has to produce at least as high a yield as keeping the decisions the same when the environment changes. So presumably it means that there was something wrong with whatever procedure they used to estimate the effect of adaptation in that case.
Probably. It has been a while since I was in the business, but the benefit of warmer temperatures tops put for maize at around 100F. And above 80F, in the absence of good irrigation maize leaves begin to 'roll' up into tubes in order to prevent loss of moisture. The rolling then presents the former bottom of the leaves to the sunlight instead of the former top, and this in turn reduces the transformation of sunlight to grain.
It is actually fairly difficult to raise maize in a truly tropical climate (sorghum, a relative, does much better) due to the rolling in the heat problem. And the original maize (teosinte) was a subtropical to temperate plant. More temperate than not.
So, for maize, hotter is better as you move towards the poles, but not as you move too much farther towards the equator. Of course, elevation and such can have an effect as well.
Considering what crops are grown where is, in large part, determined by what subsidies the government provides, my guess is that it will be a huge mess with rising temperatures, at least in that respect. I.e. it will continue to be profitable to grow crops in certain areas despite changes in growing seasons. Of course, this is just another reason the government should get out of the business of subsidizing growing certain crops.
"Adaptation can't lead to a lower yield" -- yes, that was my thought. Since the creators of the graph must have made a serious mistake (getting the sign wrong), it makes me wonder about the reliability of the other charts.
You can't observe yield with adaptation to climate change, since it hasn't happened yet, so they have to be using some indirect estimation method.
Another adaptation is the switching of what foods are eaten in what quantities. If food in general becomes more available, people switch from carbs/grains to more expensive beans or meat. The issue of reduced nutrient content in grains is not much of a problem when beans or meat become more available.
Another fantastic and very important article.
It was over a decade ago, and I simply can't find it now, but there was a New Scientist article that stated in passing that yields in the central part of the US were up more than 10% because of CO2 fertilization and extended growing seasons. If it had been the reverse -- down >10% -- it would have been the lead story everywhere.
I find Elizabeth Kolbert to be particularly disingenuous in this regard.
https://www.mattball.org/2017/01/a-rambling-rant-to-ezra-klein-re-global.html
Thanks again.
I have been wondering how polar shifting affects everything. I'm under the impression, it has been shifting a lot in recent history, from the charting I saw. If the pole has shifted "x" distance, it would be interesting to see how much it would move a certain place, say near the equator or halfway between the pole and the equator. I'm in the Subtropic zone in So. Florida which makes it a very interesting study, as I've read the Temperate zone starts near Orlando, only a couple of hours north with major differences in flora and growing zones. I've personally not noticed much difference in temperatures down here and the flooding is not unusual, as much of So. Florida was dredged into existence. The Port of Miami docks and ground under all the buildings and equipment, as an example, did not exist until the Army Corp of Engineers and private developers started digging up Florida. Many of our seawalls require constant refilling of soil, to be replace behind them, as it is constantly being washed back into the waterways. especially along the Intracoastal Waterway, Ocean and Key Biscayne. As a kid in Ft. Lauderdale, I could dig down less then 3 ft. and hit the water table in my backyard, and I was 4 or 5 miles, as the bird flies, from the ocean. I always just assumed, perhaps erroneously, that the shifting deserts were also partly caused by polar shifting, in addition to continental shifting and other factors.
All this info brings up a major question on temperature modeling and I just don't believe the models can take all these factors into account and provide a meaningful result. Maybe the folks at the U.N., WEF and Joe Biden, are smarter than all the scientists who have raised similar concerns that are ignored by the MSM. We better start pushing back harder before the totalitarian oppression gets worse. Was the plandemic a trial run?
You may also find this recent post on the EA forum of interest, which argues that given the risk of nuclear winter, volcanic winters, and “impact” winters on sunlight, more global warming is good https://forum.effectivealtruism.org/posts/x2vELt7iwaZebHBEn/more-global-warming-might-be-good-to-mitigate-the-food
Some studies also show both fauna and flora do better during warmer periods.
I recall reading some time ago that much of the increase in average temperatures recorded comes not from an increase in daytime temps but increased nighttime temps. If that is true, it leads me to think
The changes might have even less of an effect on plants as it simply lowers the variability of their daily temperature range. Then again, maybe some plants do need a bigger swing in temperature for some reason I am unaware of.