A Bit of Climate History

One of our mantras at The Pipeline is "Climate Changes. Always Has, Always Will." This fact, which we've discussed in various contexts, is important to remember, as is Christopher Horner's addendum -- somehow, "saying 'climate changes' makes one a 'climate change denier.' Go figure."

For more of this genre of "climate change denial," check out the Ango-Irish pop historian and political commentator Ed West discussing Great Britain's recent heatwave with an eye towards history. He begins his post with a discussion of climatologist Hubert Lamb, who first noticed that descriptions of European agriculture from centuries past made little sense in the context of the modern climate.

Lamb concluded that Europe must have been considerably warmer during the Middle Ages, and in 1965 produced his great study outlining the theory of the Medieval Warm Period; this posited that Europe was at its hottest in the High Middle Ages (1000-1300) and then became unusually cool between 1500 and 1700. Since then, Lamb’s thesis has been reinforced by analysis of pollen in peat bogs, as well as the radioactive isotope Carbon-14 found in tree rings (the less sun, the more Carbon-14).

Somehow, we managed.

Lamb's first clue was an oddity which we've written about before in this space, namely the fact that Medieval England was renowned for its vineyards, whereas nowadays, an old joke holds that it takes four men to drink English wine: "one to drink it, two to hold him down, and the other to force it down the victim’s throat." More West:

[F]rom 900 A.D. the continent began warming up. The increase in temperature led to ten or even 20 days extra growing season and that meant far more food; during the medieval warm period England’s population went from 1.5 to 5 million, and France’s from under 6 to between 17 and 21 million. (Indeed France, generally, had a massive pre-modern population). In Europe as a whole, the number of people may have increased four-fold.... And during the height of this long summer, vineyards were found across the south of England.

Sounds great, but of course a changing climate can have costs too, which West certainly does not minimize:

Farmers in the Saastal Valley in Switzerland were probably the first to observe what was happening, back in the 1250s, when the Allalin Glacier began to flow down the mountain. Surviving plant material from Iceland suggests an abrupt decrease in the temperature from 1275 — and, as Rosen points out, a reduction of one degree made a harvest failure seven times more likely. From 1308 England saw four cold winters in succession; the Thames froze, chroniclers recalling dogs chasing rabbits across the icy surface for the first time....

Drenched and starved of sunlight, the crops failed across Europe. The price of food doubled and then quadrupled. By May 1316, crop production in England was down by up to 85 percent and there was ‘most savage, atrocious death’, as a chronicler put it. The Great Famine killed anywhere between 5-12 percent of the European population, although some areas, such as Flanders, suffered far worse death rates, losing up to a quarter of their population to hunger.

The facts are brutal, but the events which precipitated them are natural. This occurred before the industrial revolution, and in a world without fracking or gas-and-diesel driven automobiles. Moreover, it should be noted that global warming has tended towards human thriving, whereas cooling has tended to be an occasion for concern.

Contra the confident claims of the ignorant, the origin of these changes remains mysterious. As theoretical physicist and self-proclaimed "climate heretic" Freeman Dyson would often say, "The real world is muddy and messy and full of things that we do not yet understand," unlike the overly-simplistic models employed by the climate change industry. The context is key, but asking for the context gets you labelled a denier. Go figure.