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%.
bones says:
July 5, 2013 at 7:58 pm
Question for Leif: What was the cause of the cooling coincident with the Maunder minimum?
Slide 20 of http://www.leif.org/research/Does%20The%20Sun%20Vary%20Enough.pdf shows one reconstruction of global temperatures and a reconstruction of solar activity [although labeled ‘TSI’ it is really constructed from the cosmic ray record]. You can find some wiggles that match and some that don’t, just as you would for random data. The climate has natural variation which sometimes coincides with the natural variations of solar activity. No further causes need to be invoked.
Caleb says:
July 5, 2013 at 8:03 pm
What use is it to me to hear a forecast is basically impossible?
Some people subscribe that some prediction [even if wrong] is better than no prediction. They take solace in the fact that perhaps they can ‘do’ something, which in itself has therapeutic value.
I have to give an “attaboy” to Leif – excellent persistence in addressing a wide variety of comments.
I do think that some just accept this post “as is” because it fits their preferred world view (that it is all about the sun) but a true skeptic should question all hypotheses , not just the ones they don’t like. I like Leif’s skepticism.
The volcanic hypothesis presented by Leif is as plausible ( if not more) than solar hypothesis presented by others. To really move this discussion beyond this point though, some serious research would need to be done & presented to support the hypothesis.
Gaia plays games that last millions of years, short-term luck is exactly that.
Leif says:
Slide 20 of http://www.leif.org/research/Does%20The%20Sun%20Vary%20Enough.pdf shows one reconstruction of global temperatures and a reconstruction of solar activity [although labeled ‘TSI’ it is really constructed from the cosmic ray record].
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. In more recent times, the warmistas lean heavily on the idea that the global warming of 1976-2000 can only be explained by anthropogenic GHGs. Yet, the earth warmed at the same rate in 1915-1944 when CO2 hardly contributed. That leaves solar activity and oceanic cycles as the possible causes of the warming in this earlier period. If it were a solar effect, it would need to be an order of magnitude larger than any realistic changes of TSI.
I think that even the minor global oceanic temperature changes that correlate with the solar sunspot cycles requires a variation of solar surface heat flux that is an order of magnitude larger than the TSI variations over the solar cycle. The real question is, how does the sun do it?
Should have said “solar driven heat flux at earth surface”
bones says:
July 5, 2013 at 9:11 pm
I agree that TSI variations are unlikely to have directly caused the LIA,
All solar activity curves follow TSI, so TSI is just a convenient label [although almost all the energy is in TSI] so if the TSI wiggles don’t match neither do any other solar index. Now, obviously the Sun does influence the climate, up to 0.1 degree C, but that is not what I would consider a major driver.
Mike, this isn’t the corn that people eat. This is the corn that is used to make ethanol, plastics, possibly high fructose corn syrup, but mainly it is used to feed hogs, chickens and cattle. I get frustrated having to say that over and over.
And the ethanol the way we use it in America is mostly as a substitute for MBTE, not gasoline. This isn’t Brazil.
Leif,
Have a look here http://www.peakprosperity.com/forum/definitive-global-climate-change-aka-global-warming-thread-general-discussion-and-questions/71?page=42#comments
Scroll down the page to #1303. If I am not badly mistaken, the required driving heat flux for 0.1C peak to peak is a lot larger than any TSI variations.
You could find ‘wiggle-matches’ at many points, between CET and global temperature data, but it would be uniwse to expect correlation between the global average and such a localised series to be meaningful.
A more robust analysis would be to comb for the best match of wiggles. Has this been done? How was the period selected and preferred against others that correlate? Are there other matches with better statistical significance?
Even if this was done, it’s a long bow to postulate some kind of correlation absent physical drivers and variation to explain it. But I can’t tell if the author looked for precipitous drops in the CET record until they found a prior period that resembled the last 30 years. Or if the initiating data was the precipitous drop mentioned, then the wiggle-matching is just coincidence, and the correlation (from the previous post) doesn’t look very good.
Climastrology.
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Good insight. The problem with the CAGW predictions and what they want to “do” is that we can’t afford their “therapy”.
bones says:
July 5, 2013 at 9:30 pm
If I am not badly mistaken, the required driving heat flux for 0.1C peak to peak is a lot larger than any TSI variations.
S [=TSI] = a T^4 [Stefan-Boltzmann law]
dS = a 4 T^3 dT [differentiate]
dS/S = (a 4 T^3 dT)/(a T^4) = 4 dT/T
dT/T = 0.1/289 [Kelvin] [289K is average global temperature]
dS/S = 4*0.1/289 = 0.001384
dS = 0.001384*1361 W/m2 = 1.88 W/m2 which is about what TSI varies during a solar cycle.
barry says:
“You could find ‘wiggle-matches’ at many points…”
Cuts both ways, barry me boy, both warming and cooling. But you’re so desperate to believe in manmade global warming, you just don’t see that.
Confirmation bias.
Looking at http://earthobservatory.nasa.gov/Features/SORCE/sorce_03.php
Quote “the TSI is larger during the portion of the 11 year cycle when there are more sunspots, even though the individual spots themselves cause a decrease in TSI when facing Earth.” There seems to be an energy battle between faculae and sunspots ” On the whole, the effects of the faculae tend to beat out those of the sunspots”. The monthly average is an energy increase, “solar energy reaching the Earth decreases when the portion of the Sun’s surface that faces the Earth happens to be rife with spots and faculae, the total energy averaged over a full 30-day solar rotation actually increases.”
Is the ‘energy’ they discuss, the same energy that influences TSI ?’
Keith Minto says:
July 5, 2013 at 10:22 pm
Is the ‘energy’ they discuss, the same energy that influences TSI ?
TSI is that very energy.
bones says:
July 5, 2013 at 9:11 pm
Yet, the earth warmed at the same rate in 1915-1944 when CO2 hardly contributed. That leaves solar activity and oceanic cycles as the possible causes of the warming in this earlier period.
And aerosols. This a period when electricity and gas replaced fires for cooking in much of the developed world and many cities in the rest of the world.
This post may just be about to get very relevant.
A volcano called Popocatepetl in Mexico has just started erupting in dramatic style, causing flights in and out of Mexico City to be cancelled.
I guess I was trying to tease out the components of the sun’s radiation that activate the sensor.
Looking at the TSI monitor itself, http://earthobservatory.nasa.gov/Features/SORCE/sorce_07.php it seems to be a heat sensor with receptive cones…”The material in the cone absorbs nearly all the Sun’s energy and heats up. By measuring the voltage needed to bring this heated cone back to the same temperature as one of the other “reference” cones, which are kept at a constant temperature, the instrument can obtain an extremely accurate reading of the TSI in watts.”
Do the components of the sun’s radiation vary enough (say pronounced sunspot activity or no sunspot activity) to influence the monitor, and, importantly, is this heat monitor a true indication of the sun’s output.?
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.
At least someone is on the ball. The TSI argument is used by many to conceal the other important factors that influence our climate. UV is dismissed out of hand by Svalgaard, but is taken seriously by many real climate scientist’s.
One should also not look at solar influence alone when comparing temperature data sets. Ocean oscillations just might also play an important role?
Reading between the line, Steven Mosher’s comment on July 5, 2013 at 5:32 pm made me wonder if he’s beginning to give more thought to the possibility of a colder future.
Keith Minto says:
July 5, 2013 at 11:28 pm
is this heat monitor a true indication of the sun’s output.?
Yes, the sensor is open to space [and the Sun] so whatever energy is coming from the Sun enters the sensor, is absorbed, and heats the sensor. To measure the heat, the sensor is kept at a constant temperature [about 30 deg C] by an electric current in a wire wound around the sensor. The amount of current necessary to keep the sensor at its constant temperature is measured. The sensor is calibrated in the laboratory so that we know what current corresponds to what Wattage. There are four identical sensors. All sensors degrade with time in the harsh space environment. The degradation is carefully monitored [and corrected for] by exposing the sensors [with shutters] to the sun for different lengths of time [longer time = ,more degradation].
Stephen Walters says:
July 5, 2013 at 11:32 pm
The TSI argument is used by many to conceal the other important factors that influence our climate. UV is dismissed out of hand
UV is a [small] part of TSI.
lsvalgaard says:
July 5, 2013 at 3:41 pm
SAMURAI says:
July 5, 2013 at 2:32 pm
BTW, the TSI dropped about 1watt/M^2 in June,
Compared to what? to May? No, May 1361.36, June 1361.39..
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Towards the end of May, TSI was around 1,362 and around the end of June, it had fallen to about 1,361.
I see TSI has been updated since I last looked at it, and now stands at 1361.2, let’s go ahead and call that about 1watt since TSI hit 1,362 towards the end of June, shall we?
TSI/sunspots look to have peaked and now starts the slow slide to the lowest solar cycle since 1715.
SAMURAI says:
July 5, 2013 at 11:53 pm
Towards the end of May, TSI was around 1,362 and around the end of June, it had fallen to about 1,361.
And in a few weeks will be back up where it was. Due to solar rotation and active regions coming and going TSI varies about one Watt/m2 on a time scale of rotation. You can see that clearly here:
http://www.leif.org/research/TSI-SORCE-Cycle-24.png
26 days later than the high value in May, TSI was already back up near 1362.
I see TSI has been updated since I last looked at
All values of TSI has been updated, so the difference stays the same. Lesson: there is nothing strange going on, the sun is just rotating.
TSI/sunspots look to have peaked and now starts the slow slide to the lowest solar cycle since 1715.
Although I predicted ‘the lowest cycle in 100 years’, your 1715 ain’t right either. Can you say 1905?
Solar cycle 24 will be the lowest cycle in 200 years, nothing like being 100 years out.
“lsvalgaard says:
July 5, 2013 at 7:07 pm”
That would be the 1783-84 eruption, which effected large areas of Europe and other regions in the Northern Hemisphere too. From memory, people died from sulphur in the ash could condensing in people’s lungs forming sulphuric acid.