Dinosaurs living in the Cretaceous period were used to feeling warm and toasty. Little did they now that they were about to be hit by a major cold snap that lasted for about 2.5 million years.A paper recently published in the journal Nature Geoscience details how, smack in the middle of the Cretaceous period, global average temperatures dropped by as much as 5 degrees Celsius (9 degrees Fahrenheit).
Scientists explain that, according to evidence they have collected and analyzed, this unexpected drop in temperatures worldwide was the result of noteworthy shifts in the global carbon cycle.
Apparently, it was around this time in our planet's history when the supercontinent Pangea broke up.
Following the break-up of this supercontinent, new ocean basins formed around Africa, South America and Europe.
Green algae and other similar organisms thrived in these new basins. As their population grew, so did the amount of carbon they absorbed from the atmosphere.
Eventually, the atmosphere was stripped of so much carbon dioxide that temperatures worldwide plummeted, only to rise again in about two million years' time, when volcanoes replenished the atmosphere's carbon dioxide stock.
Scientists explain that, as far as its impact on biodiversity is concerned, this period of global cooling was not all that different from present-day global warming.
They say that, as a result of this drop in temperatures across the globe, numerous plants and animal species either experienced a significant decrease in their population, or went extinct altogether.
“All earth system processes are operating all the time and at different temporal and spatial scales; but when something upsets the balance – be it a large scale but long term natural phenomenon or a short and massive change to global greenhouse gases due to anthropogenic activity – there are multiple, potential knock-on effects on the whole system,” Professor Thomas Wagner commented on the importance of these findings.
“The trick is to identify and quantify the initial drivers and consequences, which remains an ongoing challenge in climate research,” he went on to say.