Guest essay by David Archibald
In trying to understand how the US agricultural system will respond to lower solar activity, and thus a posited colder climate, we have to go way back. As far back as the 1970s in fact when it was still possible for academics to publish books and papers on the effects of climatic cooling. In 1977, Reid Bryson and Thomas Murray published a book entitled Climates of Hunger. The book is old enough that Stephen Schneider is credited with reviewing the manuscript, from his time as a cooling alarmist.
In their discussion of the climate of the Corn Belt, they start with the results of the archaeological excavation of an Indian village called Mill Creek Site B which was occupied from 900 to 1400 AD. This site is in northwest Iowa in the heart of the modern Corn Belt:
To put that into context, there were possibly over one thousand Indian villages on the Great Plains from Iowa to Colorado during the Medieval Warm Period. In the early 19th century when the explorers who spearheaded the European invasion of the American heartland crossed the plains, they found no corn-farming villages. They left behind the last of the agricultural tribes as they moved out onto the grasslands – the Akira and Mandan on the Missouri and the Pawnee in eastern Kansas – not to find corn fields again until reaching the Pueblos in the southern Rockies. Remnants of the villages were uncovered in the early 20th century as layers of debris covered by wind-blown soil.
The Indians at Mill Creek farmed corn and hunted elk, deer and bison as well as other animals. This is how the excavation data plotted up relative to time:
Figure 3.3 shows the percentage of each of the major hunted species at Mill Creek Site B over the 500 years from 900 to 1400 AD. Bison eat grass and deer browse on trees. The increasing proportion of bison reflects a drying climate with trees being replaced by grass. Figure 3.4 shows that the number of animals in the diet peaked in the 12th century. Figure 3.5 shows that the number of potsherds remained high after bone counts first dropped. The authors believed that corn production and potsherds were related because pottery was needed to store, cook and serve corn. The potsherd count, if read as reflection of the total number of people in the village, indicates that the total number of people in the village did not decline immediately with the reduction in game. The numbers of bones and sherds both dropped rapidly after 1300. By 1400 there were none, and no Indians either. Farmers did not occupy the region again until the mid-19th century.
In their analysis, Reid and Bryson place a lot of emphasis on wind direction. For example Fort Winnebago in Wisconsin kept weather records from 1828 to 1845. Fort Winnebago is now the town of Portage. In 1968, Professor Wahl at the University of Wisconsin-Madison compared the temperatures recorded then with records from 100 years later. His results are shown in the following table:
In every month except March, the 1800s were cooler with the biggest differences in autumn – almost seven degrees in September. Month-by-month comparisons are more important than yearly averages because they have greater implications for food production. Spring and fall temperatures determine the length of the growing season. Calculating the effect on growing degree days (GDD), the climate in the early 1800s had 680 fewer GDD. This would reduce agricultural yield by 27% relative to a 2,500 GDD corn hybrid.
Wind direction was also different with more northerly winds in the 1800s. For Septembers, winds came from the northwest and northeast 47 percent of the time in Fort Winnebago. One hundred years later, Portage records shows winds from these directions 27% of the time. Wind direction also controls rainfall with westerly winds being drier. Reid and Bryson make a stab at calculating this effect in the following figure:
This is Figure 3.1 on page 32 of Climates of Hunger. It is a map of the United States showing July precipitation decreases to be expected with a slightly expanded flow of westerlies, based on 20 years of modern weather records. Shades areas have less rainfall when westerlies are expanded. The combination of lower temperatures and lower rainfall will be a real killer. It killed off the Indian farmers on the Great Plains.
David Archibald, a Visiting Fellow at the Institute of World Politics in Washington, D.C., is the author of Twilight of Abundance: Why Life in the 21st Century Will Be Nasty, Brutish, and Short (Regnery, 2014).
One is minded to suggest that ‘drier’ is not necessarily bad, if the evaporation of moisture from soil is suitably reduced in cooler climates, if the destruction of crops through hailstorms etc is reduced in high summer and if the snowmelt from mountains occurs over a longer period in spring, thereby supplying moisture during the growing season more effectively than in hotter climates.
There is also the issue of holistic geographical realignment of crop growing centres across the USA to obtain a new reality.
Has anyone done any rigorous, reputable and defendible research on that??
I might add that this past winter also had negative AMO and negative PDO . Both may be negative during the next several decades .AMO cycles are variable but they can be negative up to 60 years as we saw 1790-1850. Past negative AMO cycles were 1900-1926 and again 1964-1995. PDO negative cycles are closer to 30 years like 1944-1976 and . AMO has peaked and may go negative in an extended way during this decade and PDO has been negative since 2007. except for a few months recently. So the period of 1829-1842 that David selected could be a sign of what lies ahead as well for the next several decades , not necessarily due to the sun but possibly due to the natural variability of the ocean cycles l
milodonharlani says:
July 7, 2014 at 12:07 pm
The Oneota & Middle Mississippian Cultures (commonly called Mound Builders) were essentially wiped out by the Little Ice Age, after having flourished during the Medieval Warm Period.
milodonharlani, I live less than two hours away from Moundville, AL, which is a major archeological site for the Mississippian Culture. Several weeks ago I had the opportunity to visit the site and tour both the mounds and newly renovated museum. The displays at the museum indicated that the area around the mounds was protected by a stockade type fence, and the information plaque attached to it asked the question, “From what or whom was the fence protecting the citizens of Moundville?” Evidently the folks from UA in Tuscaloosa don’t know either.
By the time the European’s arrived this culture had disintegrated and the five civilized tribes were left to their own devices. Where I live now (Fulton, AL) there were two of these tribes (Choctaw and Creek) who existed in relative peace with one another, and there are many evidences of their occupation here just waiting to be discovered. I’m very interested in learning more about the Mississippian Culture but have neither the time nor the money to attend classes at UA. Could you please contact me off-list (jkjcfii@yahoo.com) if you have any recommended resources concerning this Culture?
herkimer says:
“AMO cycles are variable but they can be negative up to 60 years as we saw 1790-1850.”
I don’t believe it, there are ship logs that report very reduced Arctic sea ice extent in the 1810’s, that would happen during a warm AMO.
“AMO has peaked and may go negative in an extended way during this decade..”
It hasn’t even done 20 years yet, and with the expected increase in negative NAO through the next decade, the AMO will be bouncing right back up again:
http://www.woodfortrees.org/plot/esrl-amo/every:13/plot/sidc-ssn/from:1855/normalise
Pamela Gray says:
July 7, 2014 at 2:53 pm
The percentage of bones of various species is deceptive because elk, deer and bison are all considerably different in size. Thus if you reckon a deer as one-third the mass of a bison, and equal proportion of bones would at the simplest, reflect less importance of deer in the diet and that “at its simplest” is a gross over simplification. The other point is that unless you are dealing with forest bison, which are still grazers, the preferred habitats are different, so minimally the change in species reflects a change in hunting behaviour. There is an active and very disputatious debate about how to estimate meat acquisition in archaeological sites based upon bone recovery. There are a number of different “utility indexes” that have been proposed but all have problems. There are a lot of imponderables and questions tied to the issue since bone size may affect how survivable the bone will be once buried. Large animals taken a way from camp were parted out and much of the skeleton discarded before transport. But several bones have high utility for tools or a marrow extraction and so could be transported anyway. Smaller animals might be carried back whole. The upshot is that while it is often possible to tell what animals were hunted by the creators of an archaeological deposit, it is a far more difficult to determine how important individual species were.
Considering over-hunting, in North America elk and deer were typically taken either individually or in drives where they could be corralled, killed and butchered. In Nevada antelope, jackrabbits and grasshoppers were taken the same way. Bison, prior to the horse were apparently often hunted by fire drives and “jumps” that lead effectively to the animals killing themselves. There are “jumps” or kill sites several thousand years old where less than half the animals that died were butchered. The hunters had to start at the top of a ravine full of dead animals and process as many as they could before decay ran them off. After the horse was introduced, bison hunting changed character with hunters pursuing herds but killing more individual animals. It would be very difficult to estimate accurately the “pressure” that the different forms of hunting would have on the herds. However, the fact remains that the preferred environments differ between bison and elk and deer.
urlic lyons
I did not talk about a warm AMO around 1810 . I talked about a negative AMO 1790-1850
AMO went positive about 1995 and by 2020 will be 25 years . There is nothing sacred about 20 years, just a statistical mean figure . The actual warm AMO periods are all over the place . You and I may have different opinions when it will shift to negative again and that is ok. We may both be wrong too. I just happen to judge that it will happen this decade .Yes it does bounce around but the sustained trend can be negative like 1900-1926
In particular, summers that are cooler-than-normal in the interior of NOAM are dry summers. No thermal lows, no monsoons, and, for frontal systems, weaker intrusion of cT and mT from the south.
herkimer says:
“There is nothing sacred about 20 years, just a statistical mean figure .”
I was saying that it would be unusual for the AMO to stay positive for only 20 years, and I have a few lines of reasoning that suggest the AMO should go positive again 2016-2024. I don’t see any clear reasoning behind your judgement.
I’m still waiting for the increased humidity. Are we sure our climastrologists know how warm or cold it was in the past?
@ur momisugly herkimer…it is the Sun. It has always been the Sun that sets the signature into the oceans. Your example of a negative AMO in 1900/26. Look what happens afterwards in the CONUS where temps go to all time highs in the 30s and 40s. Look at how the Dalton fits in with the 1790/1850 period. Using Dr Svalgaards elegant ssn chart I note that between cycle 17 to cycle 18 the length of the base of the minimum shortened from around 4+ years down to 2 +/- years for the following 6 solar cycles. This changed with the last solar minimum which went back to the 4 year length pattern. The 4 year base for a solar minimum looks like it is linked to a cooler time here on Earth. Would the 6 prior solar cycles show 6 cycles of cooler solar effects? I don’t know as Dr Svalgaards chart starts in 1875 and shows 4 cycles of a 4 year base for the minimum prior to the 6, two year base minimums. I partially recognize this from the standpoint of the 9 year Pac Northwest flood cycle that somehow morphs closer to 12 years after 6 cycles. It was my basic knowledge of the 9 year flood pattern that made the first connection as I started down the path of the climate change debate and started looking at charts and graphs. That stimulated my thoughts. Are we now headed for 3 or 5 more 4 year base minimums and thus 33 to 55 approx more years of a cooler period? The 19/20 year offset between PDO and AMO also sticks and connects with other aspects of the story. In any 60+ year cycle there will be shifts within that cycle. The CET clearly shows how that works. There are 1/2 patterns around 15+ years and 1/4 patterns around 7/8 years. The globe on the whole does similar although regions meld and influence each other also, but it is all driven by solar influences from the incoming energy or lack of that drives the climate system, with the oceans being the storage system for the globe. The entire solar system likely modulates the interactions through solar influencing.
Interesting sidelight is mention of use of fire by tribal people’s.
There is archaeological data from the area of Port Angeles WA, across the Strait of Juan de Fuca from Victoria BC, indicating that tribal people there used fire to create and maintainmeadows to increase interface periphery and to foster growth of edible plants. (Animals live and feed in interface not in forests.)
There are also anecdotal reports of tribal people burning underbrush near Sooke BC, on the other side of the Strait, to suppress undergrowth.
Camus lilly roots and deer were big in their diet.
Today environmentalists treat “Garry Oak meadows” as mystical, ignoring they are human creations. (The natural state of Garry Oak (aka white oak south of that line on maps that trees don’t read) is forest, typically supplanted by Douglas Fir as people say happened in the area called Metchosin on the Strait west of Victoria in the past 150 years.) So environmentalists are trying to preserve something that is doubly not natural.
J. Keith Johnson says:
July 8, 2014 at 6:39 am
OK, I will.
goldminor says:
July 8, 2014 at 5:00 pm
IMO the Pineapple Express & Chinook-induced winter floods in the PNW are definitely cyclic, related to PDO phase. I noticed this in 1995/6, recalling 1964/65 & being told by my parents & grandparents about previous occurrences.
ulric lyons
Predicting an exact date for a change in an AMO period is bit of crap shoot at the best. No one has got it right yet?
Unlike the PDO, numerical models have been unable to predict AMO cycles with any accuracy. There are only about 130-150 years of data based on instrument data which are too few samples for conventional statistical approaches. With aid of multi –century proxy reconstruction, a longer period of 424 years was used by Enfield and Cid –Serrano to develop an approach as described in their paper called, The Probabilistic Projection of Climate Risk. Their histogram of zero crossing intervals from a set of five re-sampled and smoothed version of Gray et al(2004) index together with the maximum-likelihood [MLE] gamma distribution fit to the histogram, showed that the largest frequency of regime interval was around 10 –20 years
An analysis of the Atlantic multi-decadal Oscillation(AMO ) Index or North Atlantic Ocean SST Reconstruction shows that the index or SST had major temperature dips( up to -1.7 C) every 100 years or so , namely600-1620,1720,1820,1910-1920
Best guess is by approx. 2020 another dip( future?)
see papers and article
http://www.nrmsc.usgs.gov/files/norock/products/GCC/GeophysResLetters_Gray_04.pdf
Also see article by Bob TISDALE
http://i47.tinypic.com/ekkhuc.pngAMO Reconstruction
I really have nothing more to add.
[Thank you. .mod]
Gene L says:
July 7, 2014 at 7:56 pm
Prairie Indians did light grass fires to encourage new growth, more nutritious for bison. But this IMO isn’t “agriculture”, but managing natural resources by hunters & gatherers. There is also a school of thought among archaeologists & cultural anthropologists that the Magdalenian Culture of Upper Paleolithic Europe may have “herded” reindeer in a manner similar to the Lapps (Sami) today. Horses too might have been managed to some extent by these advanced Stone Age people.
Goldminor
I got over my love affair of solar cycles after a lot of analysis and many blogs . I have no desire to reopen it . To me the ocean currents /enso/ atmosphere coupling is much more rational .
gary gulrud says:
July 7, 2014 at 9:54 pm
For Dust Bowl, please see next comment.
You’re welcome re cultivation & agriculture. My point is that there isn’t always a hard & fast, bright line between hunting & gathering cultures & “agricultural” ones. It’s more of a continuum, but detailing where a group lies on that spectrum needs careful use of language, IMO. Technically, agriculture requires domestication & more elaborate field preparation than sticking a naturally occurring food or fiber plant in a place where it’s not growing but could. Often also artificial watering in some way, but not necessarily.
As per my comment above, many H&G cultures also practice some form of natural resource management short of cultivation or pastoral keeping of livestock (besides dogs). But IMO the practices of Willamette Valley Indians & the whole NW Coast Cultural Zone were far from any reasonable definition of farming or agriculture, which of course was practiced elsewhere in pre-Columbian North America. The Pacific Coast however was largely H&G, thanks to the abundant natural resources both of the NW & California’s valleys. The long grass prairie & SW were farmed in periods of favorable climate & abandoned in inclement times.
The NW Coast peoples had among the most complex societies in pre-Columbian N. America, to include coastal whaling, large boat & structure construction & wonderful woodcarving, but could support this complexity without agriculture, due to the great natural abundance. It was also a commercial product (including slavery) society, but lots of less complex cultures practice trading, although not with conspicuous consumption on the potlatch scale. They even had a sort of incipient metallurgy, hammering naturally-occurring fairly pure copper.
Ulric Lyons says:
July 8, 2014 at 3:11 am
My comment was originally longer, with caveats for continental v. coastal regions, etc, but of course you’re right that given the nature of the atmosphere, colder is surely not always drier.
Despite some cold winters, for instance, the 1930s in the US were generally hotter than now, yet that’s when we had the Dust Bowl, made worse by unwise farming practices. The history of the Plains is largely driven by climatic cycles of moisture & drought, warm & cold, but not always rain & heat together.
Speaking of North American Indian agriculture, IMO the greatest achievement in prehistoric plant domestication (certainly for grains) was corn (maize, choclo, etc). Corn is also interesting because its genome is virtually indistinguishable from its wild variety, the grass teosinte. The enormous difference in appearance between the two varieties is thus almost entirely epigenetic, ie in when & how the genes are expressed & turned on or off. Mesoamericans also breed up domestic varieties of a lot of other crops now common. Plus of course turkeys.
The domestication of the potato (in bewildering & humorous variety, most not seen outside South America) by Andean Indians must also rank high on the scale, but is a lesser achievement than corn, IMO.
@herkimer
The tree ring based AMO reconstruction shows the late 1500’s warm, which was very cold in the CET reconstruction, warm in Maunder, and warm in the Gleissberg Minimum in the late 1800’s, but gets colder 1807-1817 in the coldest part of Dalton, also colder in the cold period in CET of 1836-1845. I think that the proxy is in error in those two periods.
milodonharlani says:
“..given the nature of the atmosphere, colder is surely not always drier.”
England tends to be wetter when cooler in summer, and when warmer in winter, there’s not much trend, or sign of an AMO signal:
http://www.metoffice.gov.uk/climate/uk/actualmonthly/17/Rainfall/England.gif
ULRIC LYONS
I think that the proxy is in error in those two periods.”
Yes I agree. The period 1650-1700 and 1850-1880 in particular seem in question . I checked these against the Greenland ice core records and they also indicated cold periods during these two periods where as the AMO proxy graph shows warming.
Though I am inclined to agree with the premise, it is hard to take a science article seriously when the author does not know that the x- axis is the independent variable and the y- axis is the dependent variable. Those graphs are a mess.
herkimer says:
“The period 1650-1700 and 1850-1880 in particular seem in question . I checked these against the Greenland ice core records and they also indicated cold periods during these two periods where as the AMO proxy graph shows warming.”
There’s no point in referring to Greenland temperatures as they usually go in the opposite direction to CET, e.g. from the coldest part of Maunder around 1690 Greenland cools towards 1730, and warms again around 1740, which is the coldest year on CET. And just before that from 1650-1654 was very warm in the UK:
http://wattsupwiththat.files.wordpress.com/2009/11/oscillating_climate2.png
http://booty.org.uk/booty.weather/climate/1650_1699.htm
Ulric Lyons says:
July 8, 2014 at 6:27 pm
As I can also report from experience there in the 1970s.
Thanks for the link.