66 million years ago, dinosaurs died due to a lack of sunlight. This hypothesis was put forward by scientists from the American Geophysical Union, a brief description of which was published in the journal Geophysical Research Letters.
According to the generally accepted theory, 66 million years ago, the Chicxulub meteorite fell on the Yucatan Peninsula, the territory of modern Mexico. This caused the Cretaceous-Paleogene mass extinction, during which more than 70% of life on the planet, including dinosaurs, disappeared.
Scientists believe that after a meteorite fell into the upper atmosphere, a hot cloud of molten solid rocks rose – this led to global forest fires and the release of a huge amount of ash into the atmosphere. The ash layer created a natural screen that did not allow sunlight to penetrate the Earth’s surface – this, in turn, led to a temperature drop of 26 ° C.
In a new work, scientists created a model to assess how emissions of dust, soot, and sulfur had an impact on global climate change. Modeling showed that the temperature drop was indeed very significant, but this factor alone was not enough for such a mass extinction.
Further analysis showed that the cause of the extinction was probably the lack of ultraviolet radiation, which was blocked by clouds of ash and soot. This stopped the process of photosynthesis for almost a year – as a result, herbivorous dinosaurs lost their food supply and died. Following them, predators also died.