Guest post by David Archibald
I will be giving a lecture in Washington in early June on my way through to the Bahamas. Following are the slides that pertain to the agricultural impact of the current de Vries cycle event – the Eddy Minimum.
The stippled line is the current Canadian wheat-growing area. The heavy black line is what that would shrink to if temperature fell by one degree Celsius. Friis-Christensen and Lassen theory applied to the temperature records of the northeastern US derive a temperature decline of 2.0 degrees Celsius to the latitude of the US-Canadian border. It therefore follows that Canadian agriculture will be back to trapping beavers by the end of this decade, as it was in the 17th century.
Many years ago, in the time before global warming corrupted most branches of science, researchers looked at the consequences of warming and cooling. Newman in 1980 was such a researcher. This is a figure he provided of where the US Corn Belt would shift to with one degree of warming, the dashed line, and one degree of cooling, the solid line. The current corn growing area is shaded. His calculation of 144 km per degree C is in line with my estimate of a 300 km shift southward in growing conditions.
And corn is a big business in the United States:
The large amount of ethanol production is a good thing in that it provides a buffer of capacity in the climatic event under way. The mandated ethanol requirement has brought the future forward.
Archeological records tell it that it has happened before. The map in the following graphic shows how Indian maize growing moved south in response to the onset of the Little Ice Age (Reiley 1979).
But it can get worse than the standard de Vries cycle climate response. That can be overprinted by a major volcanic eruption:
Mt Pinatubo erupted in 1991 and 1992 averaged 0.5 degrees C cooler as a consequence. The Dalton Minimum’s major volcanic eruption was Mt Tambora:
My generation has known a warm, giving Sun, but the next will suffer a Sun that is less giving, and the Earth will be less fruitful.
The Australian Prime Minister spoke recently of the benefits of reading Bible stories. The Bible story that all governments should be paying particular attention to is the one in Genesis about the seven years of fat followed by the seven years of lean. Otherwise another Biblical character will make his appearance – the Third Horseman of the Apocalypse, Famine.
Newman, J. E. (1980). Climate change impacts on the growing season of the North American Corn Belt. Biometeorology, 7 (2), 128-142.
Riley, T. J., and Friemuth, G. (1979). Field systems and frost drainage in the prehistoric agriculture of the Upper Great Lakes. American Antiquity, 44 (2), 271-285.