Come Hell or Supervolcano, Humanity Will Be Alright

By Nathaniel Scharping | March 12, 2018 4:10 pm
(Credit: Melkor3D/Shutterstock)

(Credit: Melkor3D/Shutterstock)

Every year or so, a fresh rash of concern about the Yellowstone supervolcano spreads across the internet. While the likelihood of an eruption there remains remote, if the caldera were to blow, it could be devastating. Previous eruptions there covered much of North America in choking ash, and likely caused sharp drops in temperature that would decimate crops today.

Living through a supervolcano eruption certainly qualifies as a doomsday scenario. But, humanity might fare better than we think. After all, we’ve already survived one. So, before you purchase a $6,000 pallet of bunker-ready foodstuffs from Costco, read this.

Big Bang

The eruption of Toba, in Indonesia, some 74,000 years ago was immense. The event spewed an estimated 720 cubic miles of rock, ash and magma into the air, and debris has turned up in India, the Arabian Sea and the South China Sea, sometimes more than 1,000 miles away. The ash from the event alone would have been deadly to life nearby, and the sulfur dioxide emitted could have had a powerful temporary cooling effect on the atmosphere. For comparison, the eruption of Mt. Tambora in 1815, much smaller than Toba, led to the “Year Without A Summer,” an especially chilly year that caused crop failures and famine in Europe.

The magnitude of the eruption has led some scientists to theorize that ancient humans may have made it through the event only by the skin of their ancient teeth. They propose that humans living at that time experienced a “population bottleneck,” an event that wipes out nearly all of the living members of a species. Traces of these near-extinction events show up even thousands of years later in our DNA.

It’s a tempting theory, but one that has been called into question multiple times by more recent research. A study of two archaeological sites in South Africa adds even more evidence that the Toba eruption may not have been as devastating to our ancestors as we thought — the inhabitants of these sites made it through just fine, says an international team of researchers.

They dug through layers of sediment at each site, unearthing a thin band of cryptotephra — microscopic fragments of glassy rock — at each that they were able to match to the Toba eruption with a chemical analysis. Time in archaeology is measured in layers of sediment, and by comparing the dirt from around the eruption to layers both before and after the eruption, they got an idea of how it affected the people living at the sites.

Volcano Shmolcano

The consensus? Not much changed, they say in a paper published Monday in Nature. Human activities at the two sites, one in a cave and another out in the open, continued at roughly the same level before, during and after the eruption. By all indications, the early South Africans carried on relatively unperturbed by the volcanic cataclysm half a world away.

The findings line up with other research hinting that huge eruptions may not have been the doomsday scenario we imagine. A study published in February led by researchers from the University of Arizona looked at plant remains from Lake Malawi in eastern Africa. They found no evidence of die-offs either, though they did see indications that the climate got slightly drier immediately after the eruption.

Though it’s likely that Toba did indeed cause noticeable changes to the environment, based just on the sheer scale of the eruption, it probably wasn’t enough to nearly wipe humanity from the face of the Earth. Our ancestors proved to be a bit hardier than we assumed.

An obvious variable in favor of the South African hominins was of course their distance from the eruption. Their dwelling place lies over 5,500 miles from Toba, far enough that they may have been spared the brunt of the fallout. Ancient humans in closer proximity might not have fared so well. Of course, given the currently chaotic nature of the timeline of human dispersal around and out of Africa, it’s difficult to know how many and what kind of hominins might have been nearer to the volcano at that time. But, it is clear that humans had left Africa by then and likely dispersed to landmasses near Toba.

What became of them after the eruption is anyone’s guess.

CATEGORIZED UNDER: Environment, top posts
  • John Thompson

    Of course it will be terrible when the next super-volcano erupts – but I agree that it will not end human life.
    If the dust does create a much colder planet for a few years – it will make life harder, but not impossible – people do live in much colder areas already.
    Agriculture would have to shift to the types of plants and animals that can tolerate the cold.
    Perhaps the Southern US would have to shift to using the types of crops that are common in the Northern US.
    It could become difficult to stay in places like Canada or Norway – but then they would have to migrate South.
    I would expect lean years – and of course greater famines in some places and the poorest not being able to afford food.
    But that’s not going to end humanity – even some evolutionary benefit if for example the most marginal 10% of humans were gone.
    May sound harsh but nature culls the herd from time to time – even humans.

    • Uncle Al

      A Trump amidst Pelosies will make hard factual decisions allowing the best people to prosper. Others will make their way by standing in ditches demanding charity and hegemony while traffic zooms by.

      Global Cooling! English farmers abandoned wheat for coarser grains like barley and rye during the Maunder Minimum. The French Court decreed wheat. France starved when in 1788 the empty royal treasury (financed the American revolution) could no longer import food and the agricultural proletariat failed. French heads rolled, 1789 and for a decade.

      Don’t sweat the small stuff. Fear central management, for there is no imaginable catastrophe that cannot be amplified by compassion (and commissions paid upon cashflow rather than results).

      • Evil_Twin

        It’s pretty funny to see someone using President Lying Scum as an example of someone using facts.

    • Van Snyder

      Agriculture can’t “shift to the types of plants and animals that can tolerate the cold” in a few months.

  • Van Snyder

    If we come to rely entirely on solar for our energy, another “year without a summer” could spell millions of deaths. Euan Mearns calculated that to provide firm power in England and Scotland, with variability as in 2016, would require 391 watt hours of storage per watt of average capacity. For an all-electric 1,700 GWe American energy economy, 665,000 GW hours would be reqired, assuming the same variability. Using the price and capacity of the Big South Australian Battery, and an estimated lifetime of five years, the cost comes to 2.8 times entire 2016 US GDP for batteries alone. A supervolcano eruption and “year without a summer” would require enormously more storage to survive. We shouldn’t put too many eggs in that basket. Wind can never provide more than 15% of total energy (about 75% of today’s electricity). The only viable alternative that doesn’t burn fossil fuels is nuclear power, but Discover Magazine doesn’t even recognize its existence.

    • Richard Oliver

      Hear Hear!

    • Kurt S

      You are forgetting that there will still be some daylight. And infrared solar panels would be even less impacted. I can’t imagine another south pacific eruption, equal to Toba, making more than a 10% loss of solar power collection in the US.

      • Van Snyder

        “Some” isn’t a number. If 2.8 times US GDP is needed every year for batteries, when solar conditions are good, a supervolcano will only make things worse, not better. Even God doesn’t have enough money to make solar and wind viable.


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