While the worst consequences of climate change are still to come, evidence of amplified warming already abounds in the Arctic. At a hamlet on the southern end of Ellesmere called Grise Fiord, whose Inuit name means “the place that never thaws out,” the Inuit have watched the sea ice that supports their traditional seal, polar bear and whale hunting decrease every year. The Intergovernmental Panel on Climate Change has warned it’s likely that the Arctic will be sea ice-free in summertime before 2050.
“The changes to the Arctic represent the single most important natural history event of our lifetime,” says Meg Beckel, CEO of the Canadian Museum of Nature, which helps support the team’s $80,000 polar expeditions. “It’s dramatic. What will it look like 100 years from now?”
Reanimating the Past
Rybczynski’s love affair with Arctic fossils began when she was a high school student in the late 1980s, learning about paleobiology from her mentor, C. Richard “Dick” Harington. But it wasn’t until she graduated from college in 1994 that she joined Harington — the museum’s curator of Quaternary zoology at the time — on a research expedition to Ellesmere Island. Two years earlier, he made a startling discovery at the island’s Beaver Pond site. Geologist John Fyles, who discovered the site, had shown Harington beaver-cut sticks from Ellesmere — a clear indication that the spot was once home to something other than polar bears — and Harington wanted to see the site for himself.
On that first trip, on an outcrop a few hundred yards from the mouth of Strathcona Fiord, he immediately picked up three bones lying on the surface.
One was from a small beaver and another from a bear. The abundant beaver skeletons were Dipoides, a species two-thirds the size of modern beavers that had been found at sites in China and Idaho dated to the Pliocene. The site gave up more beaver-chewed sticks and saplings. That, plus the diversity of other wildlife found — frogs, fish, deerlets, hares — led Harington to conclude that around 3 million to 4 million years ago, the site was a beaver-dammed watering hole.
At the time, it was a rather radical idea. “People see the Arctic as an ancient landscape that’s been that way forever,” says Rybczynski. But Harington was suggesting “right up until the last ice age, you had a forest and this great diversity of mammals, and a frog and fish and everything!” The fossil evidence was hard to ignore. It seemed to hail from the rough stretch of time that included the mid-Pliocene warming event. But they weren’t entirely sure.
By the early 2000s, Rybczynski was at Duke University, studying beaver evolution for her dissertation. But her mind kept returning to the high Arctic. Were she and Harington reading those bones properly? Were they really from the mid-Pliocene? A forest, she knew, would require more than a couple of degrees of warmth to thrive. Just how high did the thermostat rise?