Climate Change and History; Uncertain Weather, Uncertain Times

-- (historic), Climate Change, Commentary, Environment, Uncategorized

Very few history books considered the impact of weather, before it became a political issue. One was Barbara Tuchman’s 1978 book “A Distant Mirror; The Calamitous Fourteenth Century.” It used the life of nobleman Enguerrand VII de Courcy, whose life spanned the entire century, to compare the 14th century with late-20th century Europe. Weather wise it was a transitional century as the world cooled from the Medieval Warm Period (MWP) to the Little Ice Age (LIA).

As the average location of the Arctic air front moved inexorably toward the Equator the Jet Stream meandered further north and south so temperature and precipitation fluctuated widely from year to year. It also resulted in more blocking systems so that instead of weather patterns changing on a 4 to 6 week cycle in the middle latitudes they became prolonged to 12 weeks and longer.

This meant in many years it became difficult to tell summers from winters. Summers were cool and wet while winters were warm and wet. These conditions resulted in many changes and negative impacts on most flora and fauna, but not all.

Humans suffered as harvests failed, prices for basic grains grew and malnutrition and starvation increased significantly. Impact on wheat prices for four European nations is shown in Figure1. Price increase from 1200 on is not as dramatic as occurred with the onset of the LIA but is significant.

Figure 1: Wheat prices for England, France, the Netherlands and northern Italy

Prices in Dutch guilders per 100kg wheat.

Source: L.M.Libby in H.H. Lamb Climate,, Present Past and Future, 1977.

 The combination of poor harvests made malnourished people vulnerable to disease. Warm wet winters allowed bacteria, insects, and rodents usually decimated by cold to survive, which brought more disease.  It’s not surprising the Bubonic Plague swept across the world. Outbreaks occurred in China in the 1330s, but the most reported event hit Europe in 1347 and is estimated to have killed one-third of the population. General comments on population levels in Europe say, 1250–1350: stable at a high level, 1350–1420: steep decline. Life expectancy dropped significantly during the period.

 Similar conditions in the 17th century drove prices up again and plague returned. Famous diarist Samuel Pepys wrote about the conditions. He wrote about the weather on several occasions. He and the rest of the people were especially concerned about the mild winters so the government recommended action. On January 15, 1662 he wrote, “And after we had eaten, he (Mr. Bechenshaw, a friend) asked me whether we have not committed a fault in eating today, telling me that it is a fastday, ordered by the parliament to pray for more seasonable weather it hitherto had been some summer weather, that is, both as to warm and every other thing, just as if it were the middle of May or June, which doth threaten a plague (as all men think) to follow, for so it was almost all last winter, and the whole year after hath been a very sickly time, to this day.” Pepys was on the ship that brought Charles II back to England and it was his order to parliament that created the day of fasting. However, previous parliaments had ordered similar actions.

The prayers paid off because on January 26th Pepys notes, “It having been a very fine clear frosty day. God send us more of them, for the warm weather all this winter makes us fear a sick summer.” The relief was relatively short–lived because the plague returned with a vengeance reaching London in 1665. Pepys’ concern mirrors an old English saying that, “A green winter makes a fat churchyard.”

Ironically, Pepys owed his career to climate change. Because of the cooler temperatures and higher precipitation of the LIA the salinity of the Baltic gradually decreased until the herring migrated out into the North Sea.  The fishing was a mainstay of the economic union known as the Hanseatic League that gradually collapsed with only three cities attending the last meeting in 1669.  Conflict between Dutch and English fishermen in the North Sea escalated to the First Anglo-Dutch War in 1652-4. Pepys was a first class administrator whose skills with order and efficiency made him essential to the development of the Admiralty and the British Navy. When he died in 1703 another diarist John Evelyn wrote, “This day died Mr. Sam Pepys, a very worthy, industrious, and curious person, none in England exceeding him in knowledge of the navy, in which he had passed thro’ all the most considerable offices, Clerk of the Acts and Secretary of the Admiralty, all which he performed with great integrity.”

World Food Production

We are slightly more immune to weather changes and their impact on crops, but it is not helped when governments go beyond having us pray for different conditions. An historic example of government policy causing harm occurred in 1816, known as “the year with no summer”, when weather caused extensive harvest failures. Figure 1 shows a dramatic peak of wheat prices in England for that year. The government had introduced the Corn Laws to protect English producers against low-priced imports. When harvests failed in 1816 prices went through the roof.

Wheat prices have risen significantly because of droughts in Russia and generally poor harvest conditions in many parts of the world. For example, the Canadian government approved $30 per acre “for prairie farmers dealing with excess moisture and flooding”.

How will governments react as grain prices continue to rise through the winter? Will significant increases in food costs be the final straw for the Obama administration? Will prayer help?

 This article first appeared in the Canadian Free Press, August 19, 2010.