The asteroid that killed the dinosaurs might not have killed them on impact, new science finds, but dust from the collision likely played a big role in the extinction event.
A paper published in Nature Geoscience suggests that while the exact mechanism that killed the dinosaurs is still unknown, the dust stirred up from the impact could have caused massive changes that led to the extinction of the dinosaurs.
An impact in what is now Chicxulub, Mexico 66 million years ago wiped out 75% of all species on Earth, including dinosaurs. But exactly how so much life was wiped out has remained a mystery, with scientists theorizing that wildfires, volcanic eruptions or an increase in the amount of sulfur in the environment could have been responsible.
The team of Belgian researchers argued that enough attention hasn’t been paid to the amount of dust, potentially measuring in the trillions of tons, which would have been raised by the asteroid’s impact.
That amount of dust would have the capacity to block out the sun, as would soot from wildfires or large quantities of sulfur. Once the sun was blocked, a global winter would follow, with vegetation failing and setting off a chain reaction through the ecosystem as animals would no longer have access to their usual food.
The team relied on simulations of the ancient climate using measurements of fine particles recovered from a North Dakota site where a layer of dust settled.
They found dust that size could have remained in the atmosphere for as long as 15 years, blocking the sun enough to stop photosynthesis in plants for up to two years. The cloud would also have cooled the planet by 15 degrees Celsius.