Guest essay by David Archibald
This post drew attention to the similarity between the recent warm decades and the period leading up to the extremely cold year of 1740. Now let’s investigate how a 1740-type event might play out. This graph shows the average of the monthly temperatures for the years 1736 to 1739 plotted with the monthly temperatures of the year 1740:
With respect to growing conditions, the 1740 season was a month later than the average of the previous five years and the peak months of the season were 2.5°C cooler. To get a perspective on how a repeat of 1740 might affect growing conditions in the Corn Belt, Bill Fordham, advising the grain industry in the Midwest, has kindly provided an update on the current season:
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“So far here in the center of the Midwest, the 2013 growing season is almost identical to 2009 in regards to Growing Degree Days (GDD).
In 2009 48% of the corn was planted by May 12 and 62% was planted by May 19.
In 2013 18% of the corn was planted by May 12 and 71% was planted by May 19.
In 2009, we never received a killing frost until November 5 when the low was at 28F. The Midwest had a huge crop that was wet and light test weight, but never got killed by a frost. In 2009, the total GDD accumulation from May 15 thru September 30 was 2,530 GDD.
The bulk of the corn planted in the Midwest ranges from 2,300 to 2,700 GDD (based on Fahrenheit). With the volcanoes that have been erupting in Alaska and Russia, especially with Mt Sheveluch erupting to 7.4 miles on June 26, I will be surprised if we get through the month of September in 2013 without an early killing frost. If the heat dome and high pressure ridge stays centered in the west and over Alaska until Labor Day, the clockwise rotation will pump the cold air south over the Midwest along with the ash. There are millions of acres at risk in IA and MN, that are 2-3 weeks behind normal.
After silking, it takes 24-28 days to reach the Dough Stage when kernel moisture is about 70% and about 50% of the total dry matter has accumulated in the kernel.
After silking, it takes 35-42 days to reach the Dent Stage when kernel moisture is about 55% and about 70% of the total dry matter has accumulated in the kernel.
It takes about 55-65 days after silking for a corn plant to mature and for the kernel to reach black layer, normally at 30-35% moisture.
A killing frost, <30F, will do damage whenever it occurs before black layer, the earlier the frost, the more severe the damage. A hard killing frost <28F can reduce the yield up to 25%, or more depending on the variety, even a week before black layer.
In 1974 I experienced severe loss on some late planted corn when I got rained out on May 7 and didn’t get back in to finish planting for 3 weeks. The May 7 corn yielded 190 bushels per acre and the May 28 corn yielded 90 bushels per acre, same variety.”
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Based on Bill Fordham’s experience of 1974, planting three weeks later reduced the crop yield by 50%. If the peak growth months of June, July and August are 2.5°C (4.5°F) cooler as per the CET record of 1740, that would reduce the GDD by 414.
A repeat of the climate of 1740, with a late planting and reduced heat in the three months prior to harvest can be expected to reduce crop yield by well more than 50%.
milodonharlani says:
July 6, 2013 at 11:15 am
But there is evidence that the Swedish source confused 1783 with 1739, since its details correspond to the Laki eruption-induced famine.
As I mentioned earlier this is not the case. 1739 had 20% perished, Laki had 25%. The area covered and length of lava streams are alos different.
You do have the Japanese eruptions, so IMO the jury is still out on volcanic cause for the cold of 1740
The jury is always out on something like this. The jury has not even been selected in the case for the Sun being the cause as solar activity was nothing special at that time http://www.leif.org/research/SSN-1730-1750.png
Ulric Lyons says:
July 6, 2013 at 11:17 am
So what happened to European winter warming following eruptions? http://bit.ly/13si2Ae
Weather is not climate.
Leif, … you made my point. Thanks! 🙂
Laki caused 20-25%, with one fifth being the most commonly cited figure, possibly up to a quarter. It’s clearly the same incident, down to the share of animals killed. Also, there was no mist or fog in 1739, noted around the North Atlantic in 1783.
http://en.wikipedia.org/wiki/Mist_Hardships
An eruption capable of such death & destruction would not have gone unnoticed in the historical record. The history of Iceland features the 1783 event, but no mention of such a thing in 1739. IMO the conclusion is inescapable that the Swedish source is wrong, lacking confirmation elsewhere.
You’re right that 1740 jury may well remain out, unless the prediction for 2015 come to pass, & maybe even then.
highflight56433 says:
July 6, 2013 at 11:27 am
Leif, … you made my point. Thanks! 🙂
As you do not mention what comment you referred to, I have no idea what you point was. /try again.
milodonharlani says:
July 6, 2013 at 11:15 am
IMO the Swedish source is wrong, since no record appears to exist upon which it’s based.
It happens that major [even more recent] eruptions have no historical records, e.g.
“Ice core evidence for an explosive tropical volcanic eruption 6 years preceding Tambora
Dai, Jihong et al. Journal of Geophysical Research (ISSN 0148-0227), vol. 96, Sept. 20, 1991, p. 17,361-17,366
Abstract
High-resolution analyses of ice cores from Antarctica and Greenland reveal an explosive volcanic eruption in the tropics in A.D. 1809 which is not reflected in the historical record. A comparison in the same ice cores of the sulfate flux from the A.D. 1809 eruption to that from the Tambora eruption (A.D. 1815) indicates a near-equatorial location and a magnitude roughly half that of Tambora. Thus this event should be considered comparable to other eruptions producing large volumes of sulfur-rich gases such as Coseguina, Krakatau, Agung, and El Chichon. The increase in the atmospheric concentration of sulfuric acid may have contributed to the Northern Hemisphere cooling observed in the early nineteenth century and may account partially for the decline in surface temperatures which preceded the eruption of Tambora in A.D. 1815.”
milodonharlani says:
July 6, 2013 at 11:30 am
IMO the conclusion is inescapable that the Swedish source is wrong, lacking confirmation elsewhere.
One might say that the cold of 1740 is such [weak] confirmation…
lsvalgaard says:
“Weather is not climate.”
The theory is that big eruptions will give warmer winters for Europe: http://bit.ly/13si2Ae
not that winter 1740 was confined just to Europe. There was however a sharp decline in sighted Aurora in 1740.
leif says:
I say that the albedo and round Earth are all automatically accounted for by computing dT/T and dS/S because those effects occur both above and below the division sign and thus cancel out.
But you are making the assumption that all of that TSI variability that reaches the surface raises the temperature without other effect. That is not true if some of it is absorbed. If you use the cyclical variation of sea level change over a solar cycle as an indicator of the amount of heat absorbed, it adds about another 0.5 w/m^2 to the required surface heat variability. That’s already about as large as the 0.55 w/m^2 the additional surface radiation that necessarily accompanies a 0.1C temperature change. Seems to me that the sun is producing more of an effect over a solar cycle than can be explained by the actual variations of TSI, which are more like 1 w/m^2 at the top of the atmosphere before considering abedo and latitude averaging.
bones says:
July 6, 2013 at 11:42 am
But you are making the assumption that all of that TSI variability that reaches the surface raises the temperature without other effect. That is not true if some of it is absorbed.
TSI reaching the surface is absorbed and that is what raises the temperature. I allow for some extra effect by going with 0.1C. The simple calculation only gives half of that for a 1W/m2 variation. I don’t see your point. There is no mystery here.
Dr. Svalsgaard:
An eruption that caused massive loss of life (to include 9288 people) in Iceland would not have passed unnoticed. As I pointed out, even the minor eruption of Hekla in 1725 was noted. To have wreaked such havoc, a mist or fog should have been noticed, as in 1783. Besides Bardabunga, no other document yet found but the Swedish source notes an Icelandic eruption in 1739, let alone a catastrophe caused by Hekla. But of course you’re free to credit that source if you feel it supports your case. If I were making your case, however, I’d go with the Japanese eruptions, one of which was pretty big.
Steve says:
July 5, 2013 at 1:33 pm
I’ve never seen the crops this far behind. Corn was not knee-high by the fourth of July, but it has always been waist to shoulder high in my lifetime.
Steve, perhaps we should use the logic of the warmistas and assume you’re still growing and getting taller.
Ulric Lyons says:
July 6, 2013 at 11:42 am
There was however a sharp decline in sighted Aurora in 1740.
Not anything special: http://www.leif.org/research/Krivsky-Pejml-Aurorae.png and we were approaching solar minimum…
lsvalgaard says: @ur momisugly July 5, 2013 at 2:13 pm
…..Since great volcanic eruptions are not very predictable, we can hardly be predicting a reduced crop…
>>>>>>>>>>>>>>>>>>
The problem is not just volcanic eruptions.
All it will take is major crop failures in the USA and a few other regions to repeat the 2008 Food Crisis or worse because that is what the recent changes in the Global Food system are designed to do.
What David has outlined is not the only possibility. As I said we have had two weeks of rain. It is very very soggy. This means FUNGI
Nov 2012: U.K. Winter Wheat Shows Worst Fungus Symptoms Ever Recorded
EXAMPLES FOR US CORN:
On top of that GMO corns have the same genetics so a disease will wipe out 100% of the crop if it gets infected.
Last The USA ceased keeping a strategic grain supply.
This explains what happened to the US grain reserve.
USA Hunger & Poverty Statistics
U.S. Food Inflation Spiraling Out of Control
This is WHO benefits from high food prices and no grain reserve.
(Don’t these people have any morals?)
Grain companies’ profits soar as global food crisis mounts
8/23/2012 Investing in Farmland: 4 Ways to Play the Agricultural Boom
How to manufacture a global food crisis : lessons from the World Bank, IMF, and WTO This Article explains the politics behind the food crisis.
The USA with the Food Safety Modernization Act coming into effect will join other countries who lost 50% or more of their farmers. Farmers,… suddenly find themselves heavily controlled by…. national officialdom brandishing that most vicious of anti-entrepreneurial weapons: ‘sanitary and hygiene regulations’ – as enforced by national governments… These are the hidden weapons of mass destruction of farmers and the main tool for achieving the… aim of ridding the countryside of small- and medium-sized family farms and replacing them with monocultural money-making agribusiness.
Crops produced in the USA
milodonharlani says:
July 6, 2013 at 11:53 am
If I were making your case, however, I’d go with the Japanese eruptions, one of which was pretty big.
My first post on this did just that:
lsvalgaard says:
July 5, 2013 at 1:47 pm
The bad year 1740 was likely the result of volcanic activity [Tarumai, Japan, 1739]…
lsvalgaard says:
July 5, 2013 at 1:47 pm
The bad year 1740 was likely the result of volcanic activity [Tarumai, Japan, 1739]…
This source attributes [Table 3] a spike in nitrates in Greenland Ice in 1739 to Tarumae:
http://chandra.harvard.edu/edu/formal/icecore/Student_Ice_Core_Records_Investigation.pdf
The Table on page 7 notes that there were no solar proton events at that time.
@lsvalgaard
Figure 8: http://www.leif.org/EOS/92RG01571-Aurorae.pdf
Ulric Lyons says:
July 6, 2013 at 12:16 pm
Figure 8: http://www.leif.org/EOS/92RG01571-Aurorae.pdf
Shows that the variation was similar to several other changes and thus within the normal natural variation [hint: compare with Figures 6, 7, and 9]. Nothing unusual here.
Caleb says: @ur momisugly July 5, 2013 at 8:03 pm
….IIt all depends on the timing. If the AMO has the ocean sloshing one way, the effect will be different from what will occur if the AMO has the ocean sloshing the other way….
>>>>>>>>>>>>>>>>>
Speaking of oceans ‘sloshing’ EM Smith had an intriguing post about the possible lunar effect on the oceans. Not just tides but the ~1500 year travel away from and towards the equator. link and another link on the same subject from Aalesund University, Norway
Gail Combs says:
July 6, 2013 at 12:03 pm
The problem is not just volcanic eruptions.
Of course not. Nuclear war would do nicely, too, not to speak about impacts, solar flares, etc, etc, etc.
The problem is the alarmism Archibald is peddling. There is no valid basis for ‘predicting’ a repeat of 1740 in 2015.
Leif says:
TSI reaching the surface is absorbed and that is what raises the temperature. I allow for some extra effect by going with 0.1C. The simple calculation only gives half of that for a 1W/m2 variation. I don’t see your point. There is no mystery here.
I think that there is a big mystery here. In your calculation, the radiation rate would be the same if the part of TSI variation that reaches the earth surface had been absorbed in a thin layer of black paint and then reradiated as IR. The amount radiated for 0.1C would have varied by about 0.55 watt/m^2. But if some of the heat flux is absorbed in deeper layers, it would require more heat to produce that 0.1C change. Considering just the variation of heat flux required to produce the cyclic ocean thermal expansion, I come up with a need for about 1 watt/m^2 variation of earth surface heat flux over a solar cycle.
The TSI variation over a solar cycle at the top of the atmosphere is approximately 1 watt/m^2. Accounting for albedo and latitude effects, we get about 0.18 watt/m^2 variability at the earth surface. This is too small by about a factor of 5 to account for the observed oceanic thermal expansion cycle, but since the ocean expansion is so nicely correlated with the solar cycle, I would bet that the sun is responsible. The big mystery is how does it do it?
bones says:
July 6, 2013 at 12:42 pm
The amount radiated for 0.1C would have varied by about 0.55 watt/m^2.
No, by 1.88 W/m2
since the ocean expansion is so nicely correlated with the solar cycle
Where do you get idea from?
Beng says:
bones says:
July 5, 2013 at 9:11 pm
I agree that TSI variations are unlikely to have directly caused the LIA, but I am reluctant to think that the sun played no role.
***
Why? 20k yrs ago, the earth was in the grips of the last glacial maximum — now practically all those glaciers have vanished. The sun itself had essentially the same output in both cases.
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It is well known that the solar flux at high latitudes varies strongly with changes of earth orbital eccentricity and axis inclination on about a 110,000 year period known as a Milankovitch cycle. The sun might remain relatively constant, but its effect on earth is not.
What about the other memorable cold years during the LIA?
http://en.wikipedia.org/wiki/River_Thames_frost_fairs
Although worse on the continent than in Britain, this is supposed to have been the coldest winter in the past 500, at least in Europe:
http://en.wikipedia.org/wiki/Great_Frost_of_1709
I’ve seen meteorological explanations for it, but apparently climate models don’t generate the event. Among its important historical consequences was contributing to the failure of Swedish king Charles XII’s invasion of Peter the Great’s growing Russian empire.
lsvalgaard says:
“Shows that the variation was similar to several other changes..”
Yes several other cold episodes. I have no doubt that the cause of 1740 was solar, cold shots are common close to solar cycle maxima because of the typical Ap drop there, and I can map astronomically exactly where the stronger cold shots in Jan-Feb, May-June and Oct-Nov of 1740 were.
Ulric Lyons says:
July 6, 2013 at 12:53 pm
I have no doubt that the cause of 1740 was solar, cold shots are common close to solar cycle maxima because of the typical Ap drop there, and I can map astronomically exactly where the stronger cold shots in Jan-Feb, May-June and Oct-Nov of 1740 were.
I say beware of people who have no doubt and can map things exactly. I find your claims unconvincing in the extreme. But you may find a audience among all the gullible people around.