Ross Secord, a researcher from the University of Nebraska-Lincoln theorizes how a past global warming that occurred about 56 million years ago could have been influenced by an even older pulse of warming and how this could apply to modern times.
“That has implications for climate models designed to predict the consequences of future global warming,” said Secord, who studied fossils collected from the Bighorn Basin in north-central Wyoming. He and his team of colleague researchers pulled their conclusions from analyzing the hydrogen isotopes in mammal teeth from that age, which reflected the temperature changes.
The period in cause is called the Paleocene-Eocene thermal maximum (PETM), and was marked by geologically rapid climate change. “You could think of it [Bighorn] as an ancient laboratory where the global warming experiment has already happened,” Secord said. “You could look at it and try to determine what’s happened in the past and maybe draw some inferences from that as to what we can expect to see happen with global warming in the future.”
The upcoming global warming is thought to be somehow similar to the PETM, with 10 to 15 degrees Fahrenheit warming. The last time this phenomenon happened, it moved plant species some 900 miles north in North America and caused the extinction of many ocean microorganisms.
“Many scientists have thought that warming was the direct result of the release of this light carbon, but we found evidence from stable isotopes that warming actually preceded the release of this light carbon,” Secord said. “This implies that there were two sources of warming.”
The “final” conclusion was that there’s a need to further debate this matter. “But we think it’s really important to understand the sequence of events before and during the PETM in order to understand the causes of abrupt climate change and the earth’s response to that climate change.”
These and future findings could help us plan our future hundred years or so, to adapt wisely to the new weather and climate conditions.