Hot hypothesis: Planetary scientists Brandon Johnson and Alexandria Johnson, experts in craters and clouds respectively, sought to understand how a single asteroid impact could have devastated the entire global ecosystem. Their answer is that the asteroid sent up a cloud of planet-smothering dust, bathing the Earth in thermal radiation so intense that most species could not survive. (Courtesy: Purdue University/Kelsey Lefever)

As wildfires and extreme heat events rage across the world, “apocalyptic” has become an increasingly common descriptor. These climate disasters are not unprecedented, however. New research suggests they may have been the main mechanisms behind the mass extinction event that killed the dinosaurs – and much other life on Earth – 66 million years ago.

Our modern understanding of this extinction dates back to 1980, when the father-and-son, physicist-and-geologist team of Luis and Walter Alvarez presented evidence that it was triggered by an asteroid strike.…