The Little Ice Age

Podcast Transcript

Approximately 700 years ago, something happened to the Earth’s climate.

The world started to cool down. It wasn’t dramatic enough to cause another ice age and cause ice caps to cover the poles of the Earth, but it did result in significant changes.

In fact, many historians think for a period of about 500 years, this shift in the climate dramatically influenced human history.

Learn more about the Little Ice Age and how it changed humanity on this episode of Everything Everywhere Daily.

History can be looked at in different ways.

You can look at some great leaders in history and say that this person did such and such and changed the course of history.

You can look at technology and say that some tool revolutionized how we do something, and that changed the course of history.

You can look at events and say that this battle or this decision was a pivotal moment that changed the course of history.

All of these perspectives are correct. People, technologies, and events all shape history, but they all work on different levels. The outcome of a battle will be determined by the people taking part. A great leader will be constrained by the technology of their era.

I’ve done previous episodes on all of these things, events, people, and technology, and I’ve outlined how they all have changed history.

However, some things influence history, which are at a level even beyond these.

One of these high-level macro influences is climate.

Climate is something we don’t usually think about because climate only tends to change over the course of centuries. However, we have been able to detect historical climatic events and knowing what happened, it is possible to view history through this lens.

One example of a climatic event that shaped history is the Roman Climatic Optimum. This was a period from about 250 BC to the year 400 when the climate around the Mediterranean was warmer than average.

This small warming resulted in longer growing seasons for crops and greater agricultural abundance. It also just so happened to coincide with the rise of the Roman Republic and the Fall of the Roman Empire.

Another major climatic event was the Younger Dryas which took place 12,900 to 11,700 years ago. This was a 1,200-year return to glacial conditions which radically changed humanity.

The end of the Younger Dryas coincided with the rise of agriculture and civilization, a topic on which I’ve touched upon in several other episodes.

So too, is the case with the climatic event, which is the subject of this episode, the Little Ice Age.

Despite its name, the Little Ice Age was not an actual ice age. It was neither global in scope nor severe enough to cause ice caps to cover the Earth.

The Little Ice Age was a localized cooling event that was centered around the North Atlantic, primarily affecting Europe and North America but all of the Northern Hemisphere.

Because we are dealing with large-scale climatic events over a long period of time, putting dates on the start and end of the Little Ice Age is difficult.

The start of the Little Ice Age is usually given as the 14th century, and the end is usually given as the middle of the 19th century. Again, these dates are a bit fuzzy, and you can find people who will give different dates, sometimes starting a century later.

It also wasn’t a single climatic event. During this period, there were several minor warming and cooling cycles. In particular, there were three rather severe periods of cooling around 1650, 1770, and 1850.

The overall mean temperature in the Northern Hemisphere during this period was 0.6 °C or 1.1 °Farenheit cooler than the average during the one-thousand-year period between the years 1000 to 2000.

That might not sound like a lot, but that is an average. It meant cooler summers and cooler winters, with some years being considerably colder.

So what exactly happened, and how do we know what happened?

Historically speaking, these events are rather recent. We have ample evidence in the form of writings and paintings which depict the climate during this period.

There is a long list of events that occurred during this period, which would be very out of place if they happened today.

In the early 14th century, the Baltic Sea froze over twice. Once in 1303 and another time in 1307. This is a rare but not unheard-of event. For example, over the last 300 years, the Baltic has frozen over 20 times, most recently in 1987.

Iceland would frequently become completely locked in by sea ice. When the seas around the island froze, no ships could come in or out until it melted.

In 1658, Sweden invaded Denmark by marching over the ice. This was known as the March Across the Belts, and it was something that was otherwise impossible.

Rivers and canals in Europe would regularly freeze over. There are many paintings of people skating on the canals of Amsterdam, which were created in the 17th, 18th, and early 19th centuries. Canals have hardly ever frozen over in the last 200 years.

Entire villages in Switzerland were destroyed by advancing glaciers. The ice advanced down mountain valleys and just bulldozed everything in their path.

There was one year when Lisbon had eight snowstorms. This is for a city where it seldom snows.

There are many, many more anecdotes from the period which demonstrate the fact that it was much colder than it had been before. Not only were winters colder, but they lasted longer. There was more snow on the ground, which stayed there later in the year.

This wasn’t the big problem, however.

During the worst part of the Little Ice Age, which occurred from 1560 to 1630, a period known as the Grindelwald Fluctuation saw greatly reduced agricultural output.

This period was before the industrial revolution, so the entire economy of every country was based on agriculture.

The Great Famine of 1315–1317 was the first in a series of disasters which is known as the Crisis of the Late Middle Ages.

The next disaster was, of course, the Black Death. While the proximate cause of it was the spread of disease by mice, there has been shown to be a correlation between climate downturns and pandemics. The worst pandemic prior to the Black Death was the Plague of Justinian, which took place right when the Roman Climatic Optimum had ended.

During the Grindelwald Fluctuation, agricultural land in Europe actually decreased, as did Europeans themselves. The average height of Europeans during the period shrunk by 1 inch or 2 centimeters due to malnutrition.

Reduced agricultural output was one of the driving forces behind Europeans leaving for the New World.

Things weren’t much better in North America, however. The few European settlers in North America in the early 17th century saw extremely harsh winters and late frosts. The native people of North America were not exempt and had high rates of mortality as famine set in with them as well.

They saw crop failures, and the population of wild animals they hunted decreased.

The Little Ice Age also affected precipitation patterns. When the colonists who settled the Roanoke Colony arrived, they unknowingly arrived in the middle of one of the worst droughts in the history of the eastern seaboard.

In the winter of 1641-1642, the entire Massachusetts Bay froze over.

If you have ever heard the stories of the harsh winters which early settlers had to suffer through….they were really harsh. Far worse than almost anything we’ve seen in our lifetimes.

Records kept by the Maya and Aztecs in Mexico show that they, too, suffered from decreased rainfall during this period.

Asia mostly avoided the worst of the extreme cold temperatures that Europe and North America suffered, but they still did see the effects of the Little Ice Age. Agricultural productivity decreased, mostly due to drought, and there were famines in China as well.

This might have been a contributing factor to the fall of the Ming Dynasty.

The late 17th century is considered to be one of the coldest periods in Chinese history.

As everything at this time was linked to agricultural productivity, decreased production had ripple effects that affected every part of society.

High food prices meant more social unrest. When things went bad, there was a natural tendency to blame it on some group. Jews were often a convenient scapegoat in Europe. Catholics and protestants were also blamed, depending on where in Europe you happened to be.

Wars broke out, including the devastating 30 Year war which ravaged parts of Europe, killing over half of the population in some areas.

When conditions improved in the early 18th century, agricultural productivity increased, wars in Europe decreased, and the Enlightenment began.

The Little Ice Age also saw technical innovations as people learned to cope with the colder weather. Chimneys became the norm in buildings, buttons spread in popularity to keep clothes fastened, and undergarments became popular.

It is important to note that the Little Ice Age and a colder climate were usually not a direct cause of most of the bad things which happened. No one said, “hey, it’s cold out. Let’s go to war.”

Rather, the colder climate echoed through society in the form of lower agricultural output, higher food prices, and then dissatisfaction and discontent. Each of those things being influenced by people, technology, and events of the period.

Most people had no clue what was going on as these changes took place over the course of decades. For the average person, they could grow up and live their entire life thinking that what they experienced was the norm. They had no idea.

So, the Little Ice Age happened, but what caused it? Why did temperatures drop for a period of over 300 years?

Well, no one knows for sure, but there are several theories.

The first is that it might have had something to do with Milankovich cycles. I’ve previously done an entire episode on this, but basically, there are slight changes to the Earth’s orbit over time which can influence the weather.

We know ??Milankovich cycles happen, but we don’t know if they can manifest over periods as short as 500 years.

Another theory is solar activity. It might be that the sun was just less active during the period. Computer modeling shows that this could explain colder winters but probably not colder summers.

Colder summers could be explained by increased vulcanism. The period could have coincided with increased volcanic activity, which results in more particulate matter in the atmosphere, which blocks solar radiation. We know that this was the case with the devastating Mount Tambora eruption in 1815, on which I’ve done a previous episode.

Another theory that would explain why this was mostly felt in Europe and North America would be a change in ocean currents. If the thermohaline circulation system in the Atlantic Ocean was broken by some influx of fresh water, it might have stopped warm water from being brought further north.

Yet another theory holds that it was all due to a large decrease in human population due to a combination of the Mongol Invasions in Asia, the Black Death in Europe, and the Great Dying of the Americas due to diseases brought by Europeans.

Fewer people meant fewer emissions into the atmosphere, which led to cooler temperatures.

The truth might be some combination of several of these factors which took place at different times.

Whatever the cause, the Little Ice Age had a major role to play in shaping world history.

It wasn’t the sort of event which sits front and center in the history books, and it wasn’t even something that the people who lived through it knew was happening.

But in hindsight, we can look back at the evidence and see exactly what this centuries-long change in climate did. The frozen hand of the Little Ice Age left its fingerprints all over history and help shape the world we live in today.