Traps Erupting, Pangaea Breaking, and a Conclusion

Deccan Traps Erupt

• before the impact
• flood basalts in modern-day India
  • up to 600,000 miles covered in lava
• acid rain (SO2), ozone depletion, global cooling (SO2), global warming (CO2), etc.

Pangaea Breaking Up

• many species already going extinct due to the breakup of the supercontinent
• continents move apart → sea level rises

Conclusion

• the Cretaceous biosphere was already stressed
• the impact was the final nail in the coffin
  • this was also probably the causal factor in the extinction of the dinosaurs

Did the Dinosaurs Really Go Extinct?

• biologically, birds are descendants of dinosaurs
  • example: the Cassowary bird the is bird that most closely resembles a dinosaur in today’s age
  • crocodiles and alligators are also thought to be descendants of the dinosaurs
• the K/Pg extinction caused extinction of “non-avian” dinosaurs

How Concerned Should We Be?

• there doesn’t have to be a “mass extinction” event to be bad
• civilization killer → this is random and would probably only occur 1 in 1 million years
• we might kill our civilization on our own
  • current extinction rate is 1000 times higher than the background rate
  • if all threatened species become extinct by 2100, we would be in a mass extinction event
  • within 240-540 years, magnitude would be comparable to past mass extinctions

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