Year Without a Summer (Poverty Year)
The Year Without a Summer, also known as the Poverty Year, refers to the significant climatic anomaly that occurred in 1816, primarily affecting the Northern Hemisphere. This unusual phenomenon was triggered by the massive eruption of Mount Tambora in Indonesia in April 1815, which expelled vast amounts of ash and volcanic gases into the atmosphere. The resultant ash cloud diminished sunlight reaching the Earth's surface, leading to a dramatic drop in temperatures. As a consequence, the summer of 1816 was marked by unseasonably cold weather, resulting in severe agricultural failures, food shortages, and unrest across various regions, including North America and Europe.
Throughout the summer months, reports documented extreme weather conditions, such as snowstorms in June and frosts that devastated crops in July. The combined effects of these climatic disturbances contributed to widespread poverty and despair, with estimates suggesting over 100,000 deaths due to starvation, disease, and violence. The event is a crucial historical example of how volcanic activity can have lasting global impacts on climate and society. Modern scientists continue to study the Year Without a Summer to gain insights into the potential consequences of climate disruptions, emphasizing the importance of understanding and addressing climate change today.
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Year Without a Summer (Poverty Year)
The Year Without a Summer describes a climatological abnormality that decreased global temperatures across the Northern Hemisphere in 1816. The drop in temperatures was caused by Tambora’s massive volcanic eruption in Indonesia (then known as the Dutch East Indies) the year prior. The eruption threw so much ash and volcanic gas into the atmosphere that it lessened the normal amount of sunlight reaching Earth’s surface. As a result, global temperatures dropped, and unheard-of events like significant snowfall and plant-killing frosts occurred in mid-summer. The lack of a fertile growing season caused widespread food shortages and, coupled with other impacts, resulted in over 100,000 deaths. Because of this, 1816 has been called the “poverty year” for the widespread hardship that occurred.
Overview
In April 1815, a series of powerful volcanic eruptions occurred at Mount Tambora in Indonesia. Lasting four months, the eruptions spewed large volumes of ash and aerosol residues into the atmosphere. The haze created a dark, shadowy sky and obscured the sun from view. The ejections also blanketed settlements near Mount Tambora in ash, directly causing at least eleven thousand deaths. According to reports documented at the time, ash up to 12 feet (3.66 meters) deep covered everything within a radius of 100 miles (161 kilometers) of the source volcano. Contemporary estimates suggest that the 1815 eruption was one hundred times more forceful than the 1980 eruption of Mount St. Helens in Washington state. The Mount St. Helens blast registered a seven on the eight-point volcanic explosivity index used by the US Geological Survey. Experts believe that the 1815 Mount Tambora events comprise the most powerful volcanic eruption in recorded history.
Such strong eruptions often have significant, lasting global impacts. The sulfur dioxide ejected into the atmosphere during these events can react with water vapor, creating clouds of sulfate aerosol. Sulfate aerosols float at an altitude higher than rain clouds, and because of this, rain does not wash them out of the sky. Instead, they remain present for extended periods of time, reflecting incoming sunlight away from Earth and preventing it from reaching the planet’s surface. As a result, sulfate aerosol clouds can have significant cooling effects.
Concurrently, Earth was in the depths of the Dalton Minimum, also known as the “Little Ice Age.” This phenomenon has been assigned various dates, but generally it is agreed to have spanned from the sixteenth through the early nineteenth centuries and was marked by reductions in normal solar activity. In May 1816, scientists recorded the lowest sunspot number (0.1) ever observed to that point in history. Sunspot numbers are part of a historical index that tracks the number of observable sunspots on the surface of the sun. Lower numbers indicated reduced solar activity and were linked with cooler climate conditions on Earth.
The combined effects of the Mount Tambora eruptions and the Dalton Minimum phenomenon became apparent throughout the Northern Hemisphere during the summer of 1816, which has since become known as the Year Without a Summer or Poverty Year. At the time, people did not understand the actual cause of the severe disruption of normal seasonal weather patterns. Some scientists believed that the unusual reductions in sunspot activity were to blame. Others ascribed it to abnormal planetary alignments in the solar system. Regardless of their disagreements on the cause, people were unanimous in describing the summer of 1816 as unlike any they had ever experienced.
Between May and August 1816, weather patterns across the Northern Hemisphere were disrupted and sharply cooler than usual. These impacts were extensively documented in North America and Europe, where both scientists and laypeople tracked the unusual weather conditions. Northern New England experienced a major snowstorm on June 7–8, 1816, which blanketed affected areas with snowdrifts as high as 20 inches (51 centimeters). The New England Historical Society reported many casualties affecting livestock herds, and reports from Montreal, Canada, stated that frozen birds were found dead in city streets. On July 4, 1816, US statesman and future president John Quincy Adams wrote in his journal that storms of freezing rain left him confined to his London home. July frosts killed vegetable crops on a mass scale in Maine, worsening the impacts of similar unseasonable weather in May that had wiped out crops in Massachusetts, New Hampshire, Vermont, and upstate New York. Ice storms struck northern parts of the United States in July, and many regions experienced sudden and broad swings in weather conditions that plunged temperatures from higher-than-usual levels to near-freezing within the space of a few hours.
Throughout Europe, the summer of 1816 was unusually cold, dark, and wet. Widespread floods submerged parts of China, causing catastrophic crop failures. In India, the unusual weather patterns disturbed the monsoon season, creating conditions that caused a cholera outbreak. This outbreak eventually spread across a region spanning the Ganges River basin to the Russian capital of Moscow.
Contemporary scientists analyzing the events estimate that the average global temperature dropped by two degrees Celsius (3.6 degrees Fahrenheit), with land temperatures at sea level falling as much as three degrees Celsius (5.4 degrees Fahrenheit) below average. According to experts, volcanic eruptions of the magnitude that occurred in Indonesia in 1815 take place approximately once every thousand years. Smaller eruptions capable of noticeably cooling average global temperatures are more common, taking place about once per century.
Impact
The most profound impacts of the Year Without a Summer were caused by mass-scale crop failures and agricultural losses. This severely disrupted food security in North America, Europe, China, and other parts of the Northern Hemisphere. Grain prices in the United States soared by at least 400 percent, while the price of oatmeal spiked by nearly 800 percent. Many European cities witnessed widespread civil unrest, with citizens rioting and committing acts of arson and looting as they stole what they needed to survive. Thousands perished as a result of the food shortages, disease outbreaks, and violence. Modern-day assessments attribute at least one hundred thousand deaths to the Year Without a Summer, including the estimated eleven thousand who died in Indonesia as a direct result of the 1815 volcanic activity. The Farmer’s Almanac also notes that many people were driven to suicide by despair and financial ruin, adding untold numbers of further casualties to the documented death toll.
Although a catastrophic climate event of the magnitude of the Year Without a Summer has not reoccurred, the event stands as an important harbinger of the effects of climate change. In 1991, the eruption of Mount Pinatubo led to a period of flooding and several massive coastal storms. In the twenty-first century, scientists continue to study the effects of the Year Without a Summer to understand the global impacts of volcanic eruptions further, create climate models, understand the socioeconomic impacts of climate events, and raise public awareness of the importance of protecting the planet.
Bibliography
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Rice, Doyle. “200 Years Ago, We Endured a ‘Year Without a Summer.’” USA Today, 26 May 2016, eu.usatoday.com/story/weather/2016/05/26/year-without-a-summer-1816-mount-tambora/84855694/. Accessed 14 Sept. 2021.
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“The Year Without a Summer.” American Museum of Natural History, 2021, www.amnh.org/exhibitions/permanent/planet-earth/why-are-there-ocean-basins-continents-and-mountains/explosive-volcanism/volcanic-gases/the-year-without-a-summer. Accessed 14 Sept. 2021.