The end-Cretaceous mass extinction was rather unpleasant - The simulations showed that most of the soot falls out of the atmosphere within a year, but that still leaves enough up in the air to block out 99% of the Sun’s light for close to two years of perpetual twilight without plant growth.

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The end-Cretaceous mass extinction was rather unpleasant - The simulations showed that most of the soot falls out of the atmosphere within a year, but that still leaves enough up in the air to block out 99% of the Sun’s light for close to two years of perpetual twilight without plant growth.