In this week’s entry on Canary in a Climate World Vol. 3 we hear from Austrian paleontologist Professor Gernot Rabeder, author of more than 450 scientific papers on fossil records and the climate history of the Pliocene and Pleistocene. He draws our attention to a cave located nearly 2,800 meters above sea level in the Dolomites which was discovered in 1987 by an amateur mineral collector. The cave is far above the tree line and is surrounded only by rock, scree and sparse alpine vegetation. Yet inside the cave scientists discovered the remains of cave bears, large herbivores that can only survive in forests with abundant plant life. The bones of the bears indicate that bears throve at that altitude, or thrived if you like but it was long ago, indicating the region had to have been much warmer than today. Then the real surprise came when the bones were carbon dated.
Detailed analysis and reanalysis of the fossil remains reliably places the bones at between 44,000 and 48,000 years before the present. Which places them not in the current or previous interglacial but smack dab in the middle of the Würm glaciation (named after the Würm river in Bavaria), a period much colder globally than the present. Despite which, when Rabeder looked at clues from the alpine climate and the current vegetation patterns, he concluded that during the millennia that the cave bears lived in the Conturines cave the mountain must have been about 10 degrees warmer than at present.
This conclusion flies in the face of long-held theories about the climatic history of Europe and the alarmist dogma that until humans invented CO2, climate changed slowly if at all. So could a lengthy warm period really have set in even during the depths of the glaciation era? Rabeder notes that fossil remains of lions, leopards and hyenas have also been found in caves in the region, and even a fossil hippopotamus dated to roughly the same interval was found in the Rhine valley, whereas today such animals only live in hot regions of Africa.
In fact Rabeder says that there are nearly 300 dated fossil samples from Alpine caves that support a finding of substantial warmth in that part of the continent over an extended interval between 30,000 and 60,000 years ago. “The climate history of the region,” he states, “has been far more dynamic than is often assumed.” The fossils remind us “that the climate of the Earth has never been static. Over tens of thousands of years it has changed repeatedly, sometimes dramatically.”
In a recent survey paper he and his coauthors review some of the disputes the Conturines cave bear remains have given rise to. Various challenges to the reliability of the findings have been raised, but the findings keep being reaffirmed. And the climate history from the paleontological record is also supported by analysis of Milankovitch cycles. But climate scientists are responding as you might expect.
As Rabeder and his coauthors state:
“It is to be hoped that at some point the many ‘climate prophets’ will adapt their predictions about the future climate to the scientific data and findings. There are numerous speculations and models for the probable climate change in the coming decades and centuries. Looking back to the recent geological past would change these models significantly. Unfortunately, the message that the Conturines Cave brought us is still being ignored today.”
As too often, the people who boast most often and loudly about following the science seem not to understand the phrase.
Next week: Dr. Ken Green on 25 years in the climate trenches.
