Welcome to brain Stuff from how Stuff works. Hey, brain Stuff, it's Christian Seger. Picture what it must have been like for the dinosaurs just before they bought the proverbial farm. You're probably familiar with the basics of what happened. Sixty six million years ago. A massive asteroid hit Earth in Mexico's Yucatan Peninsula, which was at the time a shallow sea, and suddenly, relative to the long stretch of planetary history, there were no more dinosaurs. At least that's the sanitized
version of the story. For some lucky organisms, death was quick, but others probably had to spend some time staggering around in a pitch dark nightmareland. It was probably terrible, but we don't know much about what the environmental aftermath of the asteroids impact was actually like, and that lack of precise knowledge makes it tough to know much about why
some species died and others survived. A new study published in the Proceedings of the National Academy of Sciences used advanced computer modeling techniques to figure out exactly what kind of wretched hellscape drove roughly three quarters of the planet
species to extinction. The researchers found that the cheek Salube asteroid that ushered in the Cretaceous Paleogene extinction most likely triggered all sorts of cataclysmic natural disasters like earthquakes, tsunamis, and volcanic eruptions, in addition to wildfires ignited by the vaporized molten rock that rained down on every corner of
the planet. The team wanted to look at the long term consequences of the amount of soot they think was created and what those consequences might have meant for the animals that were left. It is not an insignificant amount of soot we're talking about here. The scientists estimate that these worldwide wildfires that started after the asteroid hit launched around fifteen billion tons or thirteen point six billion metric
tons of fine soot into the atmosphere. Average temperatures on Earth's surface and at sea plummeted with a fifty degree fahrenheit or twenty eight degrees celsius drop over land and a drop of twenty degrees fahrenheit or eleven degrees celsius over the oceans for more than a year and a half.
Photosynthesis would have been impossible for the terrestrial plants that weren't damaged or destroyed by the fires, and in the oceans, the phytoplankton would have been hit hard enough to tank the marine food chain for a few months, our planet's energy source was removed and a lot of animals starved. Interestingly enough, the research team's models found that a fraction of soot in the atmosphere probably would have entirely shut
down photosynthesis for a year. Actually, only five billion tons or four point five billion metric tons of soot would have done the trick. They also found that as Earth sees surface and lower atmosphere below the soot level cooled, All that soot absorbed the Sun's light, heating and changing the chemistry of the upper atmosphere, destroying the ozone layer
in the process. All the water in the atmosphere caused by the sudden warming eventually condensed into ice, creating a feedback loop that would very suddenly scour all the soot out of the atmosphere over the course of just a few months. Now For comparison, the lead author on this study, Charles Bairdeen, says the amount of soot created by nuclear warfare would be much less than what the planet saw
during this extinction. Today's episode was written by Jescelyn she Wilds, produced by Dylan Fagan, and For more on this and other topics, please visit us at how stuff works dot com