In 1815, Indonesia’s Mount Tambora blew its top and threw shade at the people of Earth after what is now known as the largest volcanic eruption in recorded history.

In North America we love our summers. From an early age we are taught that our calendar breaks up into school, and summer holidays. Ah the endless lazy hazy days…

Alas, childhood summers fade into the background as adulthood ushers many of us out of the sunshine, and into factories, cubicles and office jobs… But even after you leave school, summers are still a time for outdoor barbecues, beach visits, pool parties, and spending time outside.

Sure, when we have to work shifts that take this outside time away, we all get a bit grumpy—but it could be so much worse. And we are not talking about a “rain on every long weekend” kind of no-summer. We are talking about something a lot more serious.

200 years ago, we had a year that is actually known as “the year without a summer”.

In 1815, Mount Tambora (located in Indonesia) blew its top. The picture above is the “after” photo from one of the largest volcanic eruptions in history. Just how large was this event?

Mount Tambora
When Mount Tambora erupted it out-ranked both Mount St. Helens and Vesuvius on the Volcanic Explosivity Index (VEI). Image:

Well, volcano eruptions are measured on a scale called the Volcanic Explosivity Index (VEI), similar to the Richter and Mercalli scales (which measure the intensity of earthquakes). The VEI measures explosivity, volume of ash (tephra), and the height ash reaches into the atmosphere.

explosive eruption
The early stage of an explosive eruption, seen from space. Image: NASA

To give you a comparison, the eruptions of Mount St. Helens and Vesuvius were only ranked as 5’s on the index. The eruption of Mount Tambora was a 7, making it the largest volcanic eruption in recorded history.

38 cubic miles (160 cubic kilometres) of material was flung into the atmosphere; the explosion was reportedly be heard 1600 miles (2600 kilometres) away.

Pyroclastic flow of the 1991 explosive eruption of another stratovolcano, Mt. Pinatubo in the Philippines.

Over 10,000 people were killed in the immediate aftermath of the eruption, and the total death toll is estimated at over 70,000. Taking into account the global effects of the 1815 eruption, we can see that the impact was actually much larger.

What can a little volcano do?

There is something called the Butterfly Effect, which in chaos theory, is used to describe the interconnectedness of systems in events—such as weather patterns (it wasn’t just that movie with Ashton Kutcher). The example often given is that when a butterfly flaps its wings in one place, it can start a chain of events that leads to a hurricane on the other side of the world.

Well, imagine if that butterfly was a volcano.

Just a sweet innocent butterfly, right?

In the area immediately surrounding the volcano, plant life was burned. Crops further away from the volcano were covered in ash. Ash was found as far as 810 miles (1300 km) from the volcano. This devastated harvests in Indonesia. The eruption was strong enough to disrupt monsoon season (a key part of the agriculture cycle in south-east Asia). Between the torrential rains coming later than expected, and the flashes of cold, there was extensive crop destruction through the entire area.

Chaiten volcano
Plume from the eruption of the Chaiten volcano in Chile drifting away. Image: NASA

The changes in weather and famine from failed crops led to conditions that favoured an outbreak of cholera. The deadly disease spread from the Bay of Bengal and the river Ganges all the way to Moscow. And put a pin in that cholera problem, because it didn’t stop there.

Mt. Tambora: the caldera from the 1815 eruption is clearly visible. Image: NASA

Moving westward, the ash in the atmosphere led to brown snow in Hungary and red snow in Italy. The cool temperatures and heavy rains that swept Europe led, unsurprisingly, to further crop failures.

The food crisis was severe due to poor yields in Germany, Britain, and Ireland, and Switzerland even declared a state of emergency due to famine. This all contributed to the worst famine that Europe saw in the 19th century.

It didn’t stop at famine though, remember that devastating cholera we mentioned? It found its way to Europe on ships carrying merchantmen, leading to further outbreaks that killed many.

Tambora today. The view into Tambora’s massive crater. Image: Katie Preece Photo

North America wasn’t free from the impact of the eruption either. While 1816 was not the coldest year on record, several frosts and cold snaps occurred right in the middle of the growing season.

New England saw heavy frosts hit between June 7-8, and there were 18-20 inch (45-51 cm) snow drifts in Philadelphia and snow drifts of over 23 inches (60 cm) in Canada. Frost continued to strike the region throughout July and August, alternating with dramatic swings in temperature back to the expected warmth of summer.

Plume from Eyjafjallajokull, Iceland, drifting and spreading towards the European continent. Image: NASA

Farmers in some areas managed to bring in crops, but the decrease in production, and the difficulty in transporting produce due to the weather led to substantial increases in the price of food.

For example, a bushel of oats in 1815 cost the equivalent of $1.57, while that same bushel of oats would cost $12.98 in 1816. It is no surprise that farmers in the region referred to 1816 as “eighteen hundred and starve to death”? And the disruptions in weather continued until 1818 in some areas, leading the Germans to call 1817 “The Year of the Beggar”.

The surprising positive impacts of the year without a summer

History is a surprisingly messy thing, and humanity is a surprisingly resilient species. So while this volcano was throwing shade (in a literal way) at the people of Earth, we still did a few amazing things.

  1. We started on the road to modern medicine: the waves of cholera epidemics that were contributed to by the eruption of Mount Tambora spread throughout the world causing many deaths, but in London they also started discussions about the nature of disease and set the foundation for John Snow to discover the true nature of cholera and how diseases can propagate. Cholera is still a very much a modern day menace as well, but thanks to research that started back then we’re better able to fight it.
  2. We got fantastic literature: the famous writing challenge between Mary Shelley, Percy Shelley, and Lord Byron that resulted in the famous Frankenstein came as a result of the year without a summer. Bad weather led to the three remaining indoors in search of things to entertain themselves – the end result being some great literary work.
  3. It helped give us the bicycle: the crop failures resulting from the changing weather patterns increased the cost of food, which made it more expensive to use horses for transportation. Looking for other ways to get around helped lead to Baron Karl Drais of Mannheim creating the Laufmaschine (known as the Draisine in French), which was a predecessor of the bicycle.
  4. It jump-started arctic exploration: the earth’s climate is a complex system of wind and water currents. If these currents are disrupted and one area gets warmer, others can get colder . The eruption of Mount Tambora actually contributed to warming in the arctic regions encouraging searches for the NorthWest passage and other expeditions.

The lessons to learn

Climate change is the subject of a lot of political debate (but very little debate amongst scientists). Events like the eruption of Mount Tambora and the ensuing impact on the world’s weather show just how quickly these weather systems can change.

Ash cloud of the 1994 eruption of Kliuchevskoi in Russia. Image: NASA

All of the tragedies the world experienced in 1816 happened as a result of average temperature decrease of only 0.4–0.7 °C. That may not seem like a lot, but the impact was so memorable that we are still talking about it over 200 years later.

It makes you think just how fragile our world really is, doesn’t it?