Overview

• The extinction of non-avian dinosaurs was largely triggered by dust from the asteroid impact that blocked sunlight and shut down photosynthesis for almost two years, according to a new study.
• Researchers at North Dakota's Tanis site found that micrometer-sized dust particles persisted in the atmosphere for up to 15 years after the asteroid hit, causing a dramatic temperature drop and a virtually complete shut-down of photosynthesis for four years.
• Scientists used a global climate model to simulate the impact of fine dust, soot, and sulfur dioxide on the atmosphere, revealing that dust played a much larger role in the ensuing 'impact winter' than previously thought.
• The average size of the dust particles found at the Tanis site were considerably smaller than those previously assumed to have been produced by the impact, affecting how long the dust stayed in the atmosphere and its interaction with sunlight.
• The research affirmed that it took a slight change in the size of particles ejected into the atmosphere after the asteroid impact to dramatically change climate dynamics for years following, reinforcing the complexity of events that led to the extinction of the dinosaurs.
• The extinction event started a chain reaction that led to the collapse of the food chain and the demise of around 75% of all species, highlighting the profound effect of such an event on Earth's ecosystems and biodiversity.