New study argues intense heat and fires, not nuclear winter, killed the dinosaurs

Research published in JGR Biogeosciences suggests that a super-heated dust blanket and worldwide wildfires may have caused the rapid extinction of dinosaurs after the Chicxulub impact.

A paper in JGR Biogeosciences challenges the long-standing view that a nuclear-winter style darkness caused dinosaur extinction, arguing instead that a massive heat wave and ensuing wildfires were decisive. The impact of the six-mile-wide Chicxulub meteorite is thought to have lofted spherules and a fine dust cloud that acted as an insulating blanket, trapping thermal radiation and boosting the heat surge to roughly 3.5 times previous estimates.

According to lead author Brandon Johnson of Purdue University, this amplified heat could have ignited vegetation worldwide, producing firestorms that killed land animals within the first two hours. Aquatic species and those sheltering underground might have escaped the blaze, but the lingering dust would have darkened the sky for years, causing a severe starvation phase. So far, fire evidence is limited to North America, leaving open the question of global reach. The study underscores the importance of distinguishing rapid burning from gradual starvation in reconstructing the aftermath of the Chicxulub event.