Paleoclimatologists have found that dinosaurs had to deal with greater variation in seasons than previously thought.
Using an innovative technique, new research carried out by a team at Vrije Universiteit Brussel provides a precise picture of the Earth’s climate 78 million years ago.
Previously, it was thought that when the climate warmed like it did in the Cretaceous period, the era of the dinosaurs, the difference between the seasons would decrease.
“Much like the present-day tropics experience less temperature difference between summer and winter,” says lead author Niels De Winter.
“However, our reconstructions now show that the average temperature did indeed rise, but that the temperature difference between summer and winter remained rather constant. This leads to hotter summers and warmer winters."
The team’s groundbreaking scientific methods
In order to study the climate during this period of high carbon dioxide concentration, the researchers used the well-preserved fossils of mollusks which lived in the south of Sweden during the Cretaceous period.
These shells grew in the warm, shallow seas which covered much of Europe 78 million years ago. The team recorded monthly variations in their environment and climate using a process comparable to examining the rings in a tree.
The team also worked with scientists from the UK’s University of Bristol to develop a method of comparing modern climate models with simulations of the Cretaceous period. While previous reconstructions of the Cretaceous climate were cooler the new results demonstrate extremes of weather.
"It is very difficult to determine climate changes from so long ago on the seasonal scale, but the seasonal scale is essential to get climate reconstructions right,” De Winter explains.
The research also has the potential to show what the future of climate change could be.
"Our results therefore suggest that in the mid latitudes, seasonal temperatures will likely rise along with climate warming, while seasonal difference is maintained,” he says.
“This results in very high summer temperatures. The results bring new insight into the dynamics of a warm climate on a very fine scale, which can be used to improve both climate reconstructions and climate predictions. Moreover, they show that a warmer climate can also have extreme seasons."
The development’s implications for the way in which climate reconstructions are made. The groundbreaking research has seen De Winter being nominated for both the annual EOS Pipette Prize and New Scientist Science Talent 2021.