James Stewart

When it reaches the atmosphere, this gas reacts with oxygen and water to form tiny droplets of sulfuric acid and other aerosols. These aerosols can remain in the stratosphere for as long as a decade, reflecting sunlight back into space and plunging the Earth into a so-called volcanic winter. The super eruption of Toba 74,000 years ago released huge quantities of sulfur dioxide.

When it reaches the atmosphere, this gas reacts with oxygen and water to form tiny droplets of sulfuric acid and other aerosols. These aerosols can remain in the stratosphere for as long as a decade, reflecting sunlight back into space and plunging the Earth into a so-called volcanic winter. The super eruption of Toba 74,000 years ago released huge quantities of sulfur dioxide.

When it reaches the atmosphere, this gas reacts with oxygen and water to form tiny droplets of sulfuric acid and other aerosols. These aerosols can remain in the stratosphere for as long as a decade, reflecting sunlight back into space and plunging the Earth into a so-called volcanic winter. The super eruption of Toba 74,000 years ago released huge quantities of sulfur dioxide.

Although it's difficult to distinguish volcanic effects from background climate cycles, scientists have found evidence that the eruption was followed by a century-long period of cooling. It has also been proposed, based on archaeological and genetic data, that the climatic effect of the Toba super eruption caused our species to pass through a genetic bottleneck.

Although it's difficult to distinguish volcanic effects from background climate cycles, scientists have found evidence that the eruption was followed by a century-long period of cooling. It has also been proposed, based on archaeological and genetic data, that the climatic effect of the Toba super eruption caused our species to pass through a genetic bottleneck.

Although it's difficult to distinguish volcanic effects from background climate cycles, scientists have found evidence that the eruption was followed by a century-long period of cooling. It has also been proposed, based on archaeological and genetic data, that the climatic effect of the Toba super eruption caused our species to pass through a genetic bottleneck.

The global population might have dwindled to just a few thousand. This so-called Toba catastrophe hypothesis is contested. Some scientists doubt that the climatic effect of the Toba eruption was large enough to induce a global multi-year volcanic winter. And some question the severity of the population crash that supposedly coincided with it.

The global population might have dwindled to just a few thousand. This so-called Toba catastrophe hypothesis is contested. Some scientists doubt that the climatic effect of the Toba eruption was large enough to induce a global multi-year volcanic winter. And some question the severity of the population crash that supposedly coincided with it.

The global population might have dwindled to just a few thousand. This so-called Toba catastrophe hypothesis is contested. Some scientists doubt that the climatic effect of the Toba eruption was large enough to induce a global multi-year volcanic winter. And some question the severity of the population crash that supposedly coincided with it.

But whether or not the Toba super volcano really did cause the population of humans worldwide to shrink to a number that would fit into a large concert hall, if a similar eruption were to happen today, the effects on global agriculture would be truly catastrophic. So how worried should we be? Well, we know that these events are rare.

But whether or not the Toba super volcano really did cause the population of humans worldwide to shrink to a number that would fit into a large concert hall, if a similar eruption were to happen today, the effects on global agriculture would be truly catastrophic. So how worried should we be? Well, we know that these events are rare.

But whether or not the Toba super volcano really did cause the population of humans worldwide to shrink to a number that would fit into a large concert hall, if a similar eruption were to happen today, the effects on global agriculture would be truly catastrophic. So how worried should we be? Well, we know that these events are rare.

Topor and Toba are the only super eruptions known to have occurred in the last 100,000 years. If you travel back in time from the Toba event, the next one you would come to is another super eruption of Topor, around 340,000 years ago. But let's not get complacent.

Topor and Toba are the only super eruptions known to have occurred in the last 100,000 years. If you travel back in time from the Toba event, the next one you would come to is another super eruption of Topor, around 340,000 years ago. But let's not get complacent.

Topor and Toba are the only super eruptions known to have occurred in the last 100,000 years. If you travel back in time from the Toba event, the next one you would come to is another super eruption of Topor, around 340,000 years ago. But let's not get complacent.

At both Toba and Topor, smaller eruptions have occurred since their most recent super eruptions, and there's no reason to think that their super volcano is now extinct. Both locations are on the so-called Pacific Ring of Fire, a region of extreme volcanic hazards surrounding the Pacific Ocean, where volcanism is triggered by oceanic crusts being forced down into the underlying mantle.

At both Toba and Topor, smaller eruptions have occurred since their most recent super eruptions, and there's no reason to think that their super volcano is now extinct. Both locations are on the so-called Pacific Ring of Fire, a region of extreme volcanic hazards surrounding the Pacific Ocean, where volcanism is triggered by oceanic crusts being forced down into the underlying mantle.

At both Toba and Topor, smaller eruptions have occurred since their most recent super eruptions, and there's no reason to think that their super volcano is now extinct. Both locations are on the so-called Pacific Ring of Fire, a region of extreme volcanic hazards surrounding the Pacific Ocean, where volcanism is triggered by oceanic crusts being forced down into the underlying mantle.

Presumably one day, even if that's in thousands of years, one of these supervolcanoes will erupt catastrophically again. And in the meantime, there are other supervolcanoes to consider. Apart from Taupo and Toba, the supervolcanoes known to have hosted eruptions rating 8 on the VEI scale are clustered in the Andes of Chile, Bolivia and Argentina, and in the western half of North America.

Presumably one day, even if that's in thousands of years, one of these supervolcanoes will erupt catastrophically again. And in the meantime, there are other supervolcanoes to consider. Apart from Taupo and Toba, the supervolcanoes known to have hosted eruptions rating 8 on the VEI scale are clustered in the Andes of Chile, Bolivia and Argentina, and in the western half of North America.