“Beastly cold, and significantly reduced the light activity began to naticia the end of the dinosaurs about 66 million years ago,” says a new study and at the same time indicates that the period of mass extinction, they were much more painful and prolonged than previously thought.
For a long time, scientists believed, or rather imagined that the dust that rose with the fall to Earth a huge asteroid that was exactly what killed the ancient inhabitants of our planet. However, new computer models suggest that the period could be other factors (not only dust clouds and volcanoes) that played a key role in the death of the greater part of life on Earth.
German researchers from the Potsdam Institute for climate change (PIK) believe that precipitation in the form of sulfuric acid, formed in the upper atmosphere after re-entry into her asteroid, led to the long-term period of global cooling of the planet, which are unable to sustain the majority of species then existing dinosaur.
“Long-term cooling caused by accumulated in the atmosphere with sulfur particles, had a more significant impact on the process of mass extinction than the dust that remained in the atmosphere for a relatively short period of time,” says one of the researchers Julie Brugger.
“It was an even more important local events, such as extreme temperature at the time of the collision, and formed after it fires and tsunami”.
To come to such conclusions, the researchers used a specific set of computer models called “coupled climate models” and combine the climate calculations for the terrestrial and oceanic masses. In fact it is one of the most advanced at the moment climate models.
As in the case of the asteroid hypothesis, widely accepted in the 1980-ies, as a starting point of a new study, researchers took a fall of a giant asteroid in the place that is now a Mexican crater Chicxulub. However, this time the researchers decided to look beyond the described increased volcanic activity and transient dust clouds surrounding our planet after the impact, focused their attention on more dolgorukovoj term. And it is here “on stage” was released sulfuric acid.
Under the new proposed hypothesis, no dust from asteroid or volcanic ash, and these sulfur gases from asteroid, have become a key factor in blocking sunlight and a General cooling of the Earth’s climate.
The idea of sulfur-rich rocks around the crater Chicxulub and, as a consequence, the occurrence in the atmosphere of sulfuric acid has already been considered previously and was rejected, but the new computer models give us a better idea of how this could happen. Brugger and her colleagues believe that for 3-16 years after the fall of the asteroid, the global temperature could drop to 26 degrees Celsius, becoming below the freezing point. While the global temperature recovery could take more than 30 years.
“It was cold. Very, very cold,” says Brugger.
In addition, the researchers also suspect that the surface temperature of the oceans could also be significantly reduced. It happened as a result of lifting the warm waters closer to the surface that could cause massive algal blooms, which not only cooled them under water, but may have been toxic.
According to scientists, nature is still able to teach us important lessons of survival, due to the sudden climate change.
“It is very interesting to explore questions about how the course of evolution appeared under the influence of ancient disasters, such as asteroid strikes. Mass extinction has shown how vulnerable is the life on Earth. It is also a perfect illustration of how important is the climate for all life forms on our planet,” says George Feulner, another participant in today’s study.
“Ironically, now the immediate threat does not come from a natural global cooling and created by the technological behavior of humanity global warming”.