Aug 10, 2026 08:12 PM
https://arstechnica.com/science/2026/08/...r-species/
EXCERPTS: Mount Toba was the biggest volcanic eruption in the last 2.6 million years, and some have suggested it nearly wiped out humanity. Around 74,000 years ago, a caldera on what is now Sumatra emptied thousands of cubic kilometers of magma in about two weeks, roughly a thousand times more than Mount Pinatubo spewed out in 1991. “People thought it might have caused massive cooling of the planet, and hence threatened the survival of our ancestors,” says Jinheum Park, a geoscientist at Johannes Gutenberg University in Mainz, Germany.
Park and his colleagues went looking for the records of that catastrophe in the mud taken from the bottom of a small crater lake on the Kenya-Tanzania border. They found instead that the effects of the Mount Toba eruption lasted under two years and amounted to perhaps half a degree of cooling.
[...] “The eruption did cool and dry the region, just not to such an extent as to significantly threaten the survival of humans,” Park argues. Across the 450-year window his team analyzed, eastern equatorial Africa was already sliding from a warmer, wetter regime into a cooler, drier one, tracking a natural cooling trend recorded in Greenland ice. Against that background, Toba’s impact looks tiny. “Our study shows that the magnitude of cooling and drying after Toba was much smaller, and within the natural range of variation in the last glacial–interglacial cycles,” Park says. “Humans had already experienced and survived that.”
The limitation in Park’s study is that Chala is just one lake. “It records the regional climate signals in eastern Africa, but it doesn’t show the impact on the whole globe,” Park explains. “There should be more studies using a similar approach, at more sites where the Toba ash is found.”
The team also hopes similar approaches will be used to learn more about other huge volcanic eruptions like Los Chocoyos in Guatemala and the Oruanui eruption in New Zealand 26,000 years ago. “They were not as big as Toba, but they were still super-eruptions. It would be interesting and exciting to see what happened,” Park says... (MORE - missing details)
EXCERPTS: Mount Toba was the biggest volcanic eruption in the last 2.6 million years, and some have suggested it nearly wiped out humanity. Around 74,000 years ago, a caldera on what is now Sumatra emptied thousands of cubic kilometers of magma in about two weeks, roughly a thousand times more than Mount Pinatubo spewed out in 1991. “People thought it might have caused massive cooling of the planet, and hence threatened the survival of our ancestors,” says Jinheum Park, a geoscientist at Johannes Gutenberg University in Mainz, Germany.
Park and his colleagues went looking for the records of that catastrophe in the mud taken from the bottom of a small crater lake on the Kenya-Tanzania border. They found instead that the effects of the Mount Toba eruption lasted under two years and amounted to perhaps half a degree of cooling.
[...] “The eruption did cool and dry the region, just not to such an extent as to significantly threaten the survival of humans,” Park argues. Across the 450-year window his team analyzed, eastern equatorial Africa was already sliding from a warmer, wetter regime into a cooler, drier one, tracking a natural cooling trend recorded in Greenland ice. Against that background, Toba’s impact looks tiny. “Our study shows that the magnitude of cooling and drying after Toba was much smaller, and within the natural range of variation in the last glacial–interglacial cycles,” Park says. “Humans had already experienced and survived that.”
The limitation in Park’s study is that Chala is just one lake. “It records the regional climate signals in eastern Africa, but it doesn’t show the impact on the whole globe,” Park explains. “There should be more studies using a similar approach, at more sites where the Toba ash is found.”
The team also hopes similar approaches will be used to learn more about other huge volcanic eruptions like Los Chocoyos in Guatemala and the Oruanui eruption in New Zealand 26,000 years ago. “They were not as big as Toba, but they were still super-eruptions. It would be interesting and exciting to see what happened,” Park says... (MORE - missing details)