New computer simulation reveals grislier extinction for dinosaurs

16 Jan 2017

Illustration of asteroid hitting Earth. Image: muratart/Shutterstock

A new computer simulation investigating the extinction of the dinosaurs has found that it wasn’t dust that killed the prehistoric animals, but sulphuric acid and extreme cold.

Although we have known for some time now that the extinction of the dinosaurs was brought on by the impact of an enormous asteroid millions of years ago, the true scale of its aftermath has been debated ever since.

While many theories suggest that the resulting dust shrouding the planet in darkness was enough to kill off the dinosaurs, a new theory suggests a more grisly and brutally cold death.

In a new research paper published to Geophysical Research Letters, a team of climate scientists from the Potsdam Institute for Climate Impact Research ran a number of computer simulations replicating what would have happened following the impact.

What quickly became apparent based on the available data was that instead of the short-term effects of dust on the planet’s climate, what really killed the dinosaurs was sulphuric acid.

Following the asteroid’s impact, tiny droplets of sulphuric acid formed high up in the air after the resulting darkness, to such a scale that it killed vast numbers of flora and fauna.

“It became cold. I mean, really cold,” said lead author of the research, Julia Brugger, who suggested that temperatures dropped by as much as 26 degrees Celsius with a global annual temperature of below freezing during the first three years.

30 years to recover

“The long-term cooling caused by the sulphate aerosols was much more important for the mass extinction than the dust that stayed in the atmosphere for only a relatively short time,” said co-author Georg Feulner. “It was also more important than local events like the extreme heat close to the impact, wildfires or tsunamis.”

The effects of the sulphuric acid on the climate was so severe that the computer simulations found it would have taken at least 30 years for the global climate to recover.

Oceans too would have seen drastic changes, as the sudden temperature shift would have pushed the freezing water from the top down, raising the warmer ocean from below and releasing algae blooms that could have been toxic to any remaining life in the upper ocean.

“It is fascinating to see how evolution is partly driven by accidents like an asteroid’s impact – mass extinctions show that life on Earth is vulnerable,” said Feulner.

“It also illustrates how important the climate is for all life forms on our planet. Ironically, today, the most immediate threat is not from natural cooling but from human-made global warming.”

Colm Gorey was a senior journalist with Silicon Republic