From Vesuvius to Krakatoa, the Earth’s supervolcanoes have caused widespread destruction.
But a new study suggests that the devastation caused by these eruptions is nothing in comparison to explosions to come.
Researchers indicate that future eruptions will have the potential to affect global temperatures and precipitation more dramatically because of climate change.
They say future eruptions could plunge the Earth into ‘years without summer’ as climate change reduces oceans’ ability to buffer impacts.
From Vesuvius to Krakatoa, several volcanoes have famously erupted in the past, causing widespread destruction. But a new study suggests that the devastation caused by these eruptions was nothing in comparison to explosions to come (stock image)
Researchers from the National Centre for Atmospheric Research in Colorado focused on the cataclysmic eruption of Indonesia’s Mount Tambora in April 1815.
They found that if a similar eruption occurred in the year 2085, temperatures would plunge more deeply.
The researchers suggest that the reason for the difference in climate response between 1815 and 2085 is tied to the oceans, which are expected to become more stratified as the planet warms, and less able to moderate the climate impacts caused by volcanic eruptions.
Dr John Fasullo, lead author of the study, said: ‘We discovered that the oceans play a very large role in moderating, while also lengthening, the surface cooling induced by the 1815 eruption.
‘The volcanic kick is just that – it’s a cooling kick that lasts for a year or so.
‘But the oceans change the timescale. They act to not only dampen the initial cooling but also to spread it out over several years.’
When Mount Tambora erupted, the volcano spewed a huge amount of sulphur dioxide into the upper atmosphere, where it turned sulphate particles into aerosols.
The layer of light-reflecting aerosols cooled Earth, and led to an extremely cold summer in 1816, especially across Europe and the northeast of North America.
The ‘year without a summer’ is blamed for widespread crop failure and disease, causing more than 100,000 deaths globally.
To understand how the climate effects might differ in a future eruption, the researchers looked at two sets of computer simulations.
![When Mount Tambora (pictured) erupted, the volcano spewed a huge amount of sulphur dioxide into the upper atmosphere, where it turned sulphate particles into aerosols](https://i.dailymail.co.uk/i/pix/2017/10/30/18/45D6F0BA00000578-5032771-image-a-97_1509388111552.jpg)
When Mount Tambora (pictured) erupted, the volcano spewed a huge amount of sulphur dioxide into the upper atmosphere, where it turned sulphate particles into aerosols
The first simulated Earth’s climate from 850 to 2005, including volcanic eruptions in the historic record.
The second modelled Earth’s climate recreated a hypothetical Mount Tambora eruption in 2085.
The historical simulation revealed two key processes that helped regulate Earth’s temperature after Tambora’s eruption.
As aerosols in the stratosphere began blocking some of the sun’s heat, this cooling was intensified by an increase in the amount of land covered by snow and ice, which reflected heat back to space.
At the same time, the oceans served as an important counterbalance.
As the surface of the oceans cooled, the colder water sank, allowing warmer water to rise and release more heat into the atmosphere.
By the time the oceans had cooled substantially, the aerosol layer had started to clear, allowing more of the sun’s heat to reach Earth’s surface again.
At that point, the ocean took on the opposite role, keeping the atmosphere cooler, since the oceans take much longer to warm back up than land.
![When Mount Tambora (pictured) erupted, the volcano spewed a huge amount of sulphur dioxide into the upper atmosphere, where it turned sulphate particles into aerosols. The layer of light-reflecting aerosols cooled Earth, and led to an extremely cold summer in 1816, especially across Europe and the northeast of North America](https://i.dailymail.co.uk/i/pix/2017/10/30/18/45D6F0BE00000578-5032771-image-a-99_1509388278624.jpg)
When Mount Tambora (pictured) erupted, the volcano spewed a huge amount of sulphur dioxide into the upper atmosphere, where it turned sulphate particles into aerosols. The layer of light-reflecting aerosols cooled Earth, and led to an extremely cold summer in 1816, especially across Europe and the northeast of North America
Dr Fasullo explained: ‘In our model runs, we found that Earth actually reached its minimum temperature the following year, when the aerosols were almost gone.
‘It turns out the aerosols did not need to stick around for an entire year to still have a year without a summer in 1816, since by then the oceans had cooled substantially.’
When the scientists studied how the climate in 2085 would respond to a hypothetical eruption that mimicked Mount Tambora’s, they found that Earth would experience a similar increase in land area covered by snow and ice.
But the ocean’s ability to moderate the cooling would be substantially reduced in 2085.
As a result, the magnitude of Earth’s surface cooling could be as much as 40 per cent greater in the future.
The reason for the change has to do with a more stratified ocean.
![This increase in ocean stratification means that the water that was cooled after the volcanic eruption becomes trapped at the surface instead of mixing deeper into the ocean, reducing the heat released into the atmosphere (stock image)](https://i.dailymail.co.uk/i/pix/2017/10/30/18/45D70A6200000578-5032771-image-a-100_1509388660600.jpg)
This increase in ocean stratification means that the water that was cooled after the volcanic eruption becomes trapped at the surface instead of mixing deeper into the ocean, reducing the heat released into the atmosphere (stock image)
As the climate warms, sea surface temperatures increase.
The warmer water at the ocean’s surface is then less able to mix with the colder, denser water below.
This increase in ocean stratification means that the water that was cooled after the volcanic eruption becomes trapped at the surface instead of mixing deeper into the ocean, reducing the heat released into the atmosphere.
The scientists also found that the future eruption would have a larger effect on rainfall than the historical eruption of Mount Tambora.
Cooler sea surface temperatures decrease the amount of water that evaporates into the atmosphere and decrease global average precipitation.
Dr Otto-Bliesner, co-author of the study, said: ‘The response of the climate system to the 1815 eruption of Indonesia’s Mount Tambora gives us a perspective on potential surprises for the future, but with the twist that our climate system may respond much differently.’