The Medieval Climatic Optimum, 900-1200 AD

There is a lot of alarmist talk about the dangers of global warming. At a speech in Berlin, Barack Obama once said, “This is the global threat of our time.  And for the sake of future generations, our generation must move toward a global compact to confront a changing climate before it is too late. That is our job. That is our task. We have to get to work.” In some circles global warming has been blamed for everything from an increased severity in hurricanes (the recent Hurricane Harvey was the first severe hurricane to hit the USA in eleven years, a record) to the rise of ISIS. A professional meteorologist I know, who is skeptical about the claims of the climate alarmists, says that apparently there is nothing that climate change can’t do.

Obama’s comment reflects a common misconception: If something is happening, humans caused it. The people who think this way fail to understand how huge the atmosphere is. I don’t mean to imply that humans can’t affect the atmosphere in a local area, they certainly can, but to cause something that would alter the Earth’s climate is well beyond our ability short of an all-out nuclear war.

Former Vice-President Al Gore, a self-proclaimed expert on global warming, who got a D in the only science class he took in college and refuses to debate the issue with anyone, has made well over $100,000,000 with his book “An Inconvenient Truth” and the movie based on it. A sequel has now appeared despite the fact that, according to his first book, civilization should have collapsed by now.While providing us with all the terrifying “facts,” he has not let the terror of carbon emissions crimp his lifestyle. He owns multiple mansions around the country, one of which was described by the Nashville Electric Service as using twenty times the electricity of an average household. Gore travels extensively by private jet and, when he won the Nobel Peace Prize for his efforts in environmentalism, he threw a lavish party where the guests were flown in from all over the country as was the food, such as lobster flown in from Alaska by private jet.

While we can be irate about hypocrisy, that doesn’t help us determine if what they say is true or false. So the question is: Are we experiencing an unprecedented increase in the planet’s temperature or is this part of a normal cycle? The truth is that not only has it been this warm before, it has been warmer and it was well before there were cars pumping the dreaded carbon dioxide into the atmosphere. It is known to climatologists as the Medieval Climate Optimum.

The term Medieval Climatic Optimum refers to the period from 900 through 1200 AD. (Different sources give slightly varying dates but these seem to represent the average.) During this period the European climate changed so that it was much warmer than it is today. It was followed by a general cooling off which lasted until the end of the 19th century known as the Little Ice Age.

Since records of the temperature were not kept during this time, we have to rely on other evidence:

• Greenland was settled and farmed by Danish explorers who set out from Iceland. Throughout this period the settlers were able to farm but, once things began to cool of again, it was too cold to grow crops. The Vikings of this period were also able to colonize Newfoundland.
• Agriculture in Scotland was sufficient that the average height of men was six feet as a result of better nutrition. We don’t hink much about this today where people are routinely six feet tall but, outside of these few centuries, people were much shorter then. If you ever have the opportunity to tour London’s Westminster Abbey, note how small the coffins are. Keep in mind that these are the coffins of the nobility who had access to more and better food than most.
• In the Rocky Mountains, the snow line was 370 meters higher than it is today. The snow line refers to the altitude at which there is a permanent snow cap. Above this line the snow never melts. The higher the snow line, the warmer the temperatures.
• Data from the Sargasso Sea shows that the sea surface temperature was approximately 1°C warmer during the Medieval Climate Optimum than it is today.

Environmentalists blame this warming on excess carbon dioxide from deforestation and claim that the plagues which ravaged Europe brought it to an end. Is this reasonable?

• The world’s population at the time of Jesus was about 300 million. By the year 1000, it had only grown by 10 million (3 1/3% increase). Since the number of humans had barely increased, so would the environmental effects. Certainly it could not account for the drastic rise in temperature starting in 900AD.
• The plague which cut the population of Europe in half took place in 1348-1349, 150 years after the end of the Medieval Climate Optimum. If human activity were the cause, it should not have ended until after the population dropped.
• The people at this time knew nothing of technology. There were no cars or factories. They burned wood or peat for heat and cooking, otherwise they were agricultural. If the number of people and their relatively innocuous level of environmental damage could produce the Medieval Climate Optimum, why isn’t our current situation much worse than it is? After all, the current population is twenty-one times the size during the Medieval Climate Optimum and we are responsible for much more wear and tear on the environment. While burning wood does produce carbon dioxide, it did so before and after the Medieval Climate Optimum. Something else caused the climate change.
• If population is the problem, what is the solution? Some environmentalists have suggested reducing the world’s population to half a million or so. Others have suggested that the only way for the planet to survive is that all of us die. Oddly, they always seem to exempt themselves since they are part of the enlightened.
• Even those who do not propose such drastic measures have no trouble with establishing a centralized world government, over who the people have no control, who will decide who can live, who will die and what those who are allowed to live can do. There’s a word for this. It’s called fascism.
• The temperature on Mars has been increasing. Mars is unpopulated and, contrary to what I’ve been told by some hard-core alarmists, we can’t affect the climate on Mars.

So the truth is, we are not living in the warmest period in history. It has been warmer as well as cooler.

Text © 2017 Gary J. Sibio. All rights reserved.

Thermometer clip art is in the public domain.