Global impact of 1815 volcanic eruption blueprint for today's climate change
Global consequences of 1815 volcanic explosion could foretell impact of today's climate change, writes Cameron Dueck
Perhaps the greatest volcanic eruption of all time occurred in 1815, triggering a chain of weather-related strife and suffering that would kill hundreds of thousands of people and give today's scientists a blueprint of the sorry future we may be facing as a result of climate change.
Gillen D'Arcy Wood tells this story with skill and convincing research in Tambora: The Eruption that Changed the World, bringing together science, historic records and anecdotes from 200 years ago.
The story starts on April 10, 1815, on the Indonesian island of Sumbawa, when the top 1.5km of Mount Tambora was blown sky-high in the largest volcanic eruption in recorded history. The explosion left a gaping 6km-wide hole in the earth. Many of the first-hand witness accounts of the explosion and the days following it came from British ships that were plying the waters nearby, and they told a horrific story of destruction, with a four-metre tsunami sweeping villages from the shoreline, and two days of darkness falling within a 600km radius.
Whole villages on the Sanggar Peninsula were buried and wiped from the map, with about 10,000 people dying in the explosion and tsunami that immediately followed. In 2004, archaeologists from the University of Rhode Island uncovered a village buried under three metres of pumice and ash, and their excavations revealed a couple, frozen in time, interrupted in the midst of daily life, just as had been discovered in Pompeii, Italy.
But the worst was yet to come. The suffocating ash destroyed forests, rice paddies and livestock as well as poisoning wells, triggering starvation on a massive scale across the Indonesian archipelago. About 40,000 islanders would die of sickness and starvation, bringing immediate area deaths to more than 100,000 within weeks. Child corpses lined the beaches on nearby Bali, killed by parents who could no longer bear to watch them starve.
As horrific as Tambora's explosion was, and disastrous its ash proved to be for Southeast Asia in the weeks to follow, this book is about much more than a volcanic eruption. By the second chapter, Wood is shifting gears, moving from Sumbawa to high in the stratosphere, to locations across the globe, to economic analysis and literary evidence.
The greater story of Tambora is how it impacted global weather patterns and what it might tell us of our own future.
Tambora brings to mind another great description of volcanoes: Krakatoa, by Simon Winchester. Wood takes a somewhat similar path as Winchester, who described how the 1883 eruption of Krakatoa, also in Indonesia, helped trigger a wave of deadly anti-Western militancy among the Muslim population, linking calamitous changes in geography and climate to anomalies in human behaviour.
Wood, a professor of English at the University of Illinois, set out to establish a link between the destructive wave of extreme weather triggered by Tambora and the fragile interdependence of climate and human societies. Some of his associations appear tenuous, but the numbers don't lie.
The volcanic eruption was followed by an average decline of 1.5 degrees Fahrenheit in global temperatures for the entire decade of the 1810s, a sizeable drop given the sustained time period. Wood then links this cooling to the first worldwide cholera pandemic, the growth of opium markets in China and the Golden Triangle, the triggering of Ireland's great famine, and the first economic catastrophe of the nascent United States.
The particles of rock and ash that were spewed into the sky circled the globe for several weeks before rain washed it away, but the fine, pulverised mineral matter, gasses and sulphate aerosol would hang in the skies for more than two years, pushing layers of the atmosphere downward to displace jet streams and storm tracks.
The impact on global weather was due in part to instability caused by another volcano six years before, which had already caused cooler temperatures and thrown the global climate into disarray. When Tambora added her chaos to the mix, the summer of 1816 became unusually cold in many parts of the world, with a seasonal decline of 5-6 degrees Fahrenheit in Europe.
Much of Wood's book focuses on Europe, which is ironic given that he points out that Europe at the time largely ignored the volcano, even though Victorians were intrigued by volcanoes and the AD79 eruption of Mount Vesuvius, which had buried the Roman city of Pompeii.
But while they could ignore the far-away volcano, they could not escape its effect. Gales, storms and dreary weather caused Europe's crops to fail, with yields down by 75 per cent in 1816-17, leading to widespread starvation.
Wood also spends many pages examining the impact Tambora had on the European art scene, from the lurid skyscapes depicted by William Turner and Caspar David Friedrich to arguing that the horrors triggered by the eruption inspired Mary Shelley's Frankenstein. Shelley and Lord Byron were friends, and they spent the summer of 1816 on the shores of Lake Geneva, observing the abnormal weather conditions. Byron described the storms and ominous skies in poems such as Childe Harold's Pilgrimage and Darkness.
For the Indian subcontinent, the cooling of the earth's climate meant less ocean evaporation, which disrupted regular monsoon cycles, trigging unseasonal rains and hailstorms. That led to a widespread cholera outbreak in Bengal, a grotesque plague that spread across Burma and Siam, where victims clogged the drains of Bangkok.
In China, the severe winter following the eruption killed off more than half the forests on Hainan, and sky watchers were still commenting on the strange red skies one year later. But Yunnan province was hit the hardest: according to Wood, the drop in rice crop yields led to more intense farming of opium, with the following immigration of the region's poor spawning drug production across the Golden Triangle.
In the US, where the disastrous year after the eruption became known as "Eighteen-Hundred-and-Froze-to-Death", the cold weather killed fruit crops in the northeast, setting a record as the only year to have frosts in each of the summer growing months. The agricultural impact helped trigger the westward expansion of the continent's growing population, and the resulting volatility of global wheat prices led to the first economic recession in the new country.
Wood's description of Tambora's impact on arctic climate and sea ice is the link between this 200-year-old catastrophe and our modern climate struggle, as he uses the same language and explanations that are bandied about today in explaining climate impact in the polar regions.
In the 1810s, drought conditions in North America meant there was less warm fresh water discharging into the sea, which led to a colder, saltier North Atlantic. This in turn speeded up Atlantic currents, which caused several nearly ice-free summers. It was only years later, when ocean current and conveyor belt theories were better understood, that this became clear. And it was the warming of the Arctic in the years following Tambora's eruption that drove home Wood's point: the globe's climate is a delicately balanced thing and once knocked from its usual track the repercussions are many, and often difficult to decipher.
Wood writes convincingly but his academic style lacks emotion and storytelling flow. As harrowing as the facts and historical accounts may be - children eating white clay to quell their aching stomachs, the land wreathed in smoke from funeral pyres in Bengal - the reader does not turn the page for Wood's writing, but rather for the education.
The cholera-ravaged villages and frozen Europeans huddled in their stone huts - as sad and appalling as they may be - become repetitive and numbing in their factual description. Until, that is, you replace that wretch in burlap rags with a face you recognise or even your own, sometime in the not-so-distant future.
Although not a scientist himself, Wood delivers an intriguing anecdote of historical science, describing how humans are oblivious to the links to nature all around us. The associations and repercussions of Tambora's eruption have only become obvious to us 200 years after the fact.
The climate change we're facing today is unlikely to afford us the same luxury of reflection.