If you think global warming is something that comes around every so often, you can no longer point to the Vikings as proof.
New findings from a research team, which included University at Buffalo geologists, show that when Erik the Red settled Greenland around 985, it wasn’t because the mostly ice-covered island was any warmer at that point in history.
The team proved a 300-year warm period was regional to Europe, not global, said Jason P. Briner, an associate professor of geology.
“We were basically blown away,” Briner said.
The findings were published last week in the Science Advances journal as the world’s leaders met in Paris to debate the Earth’s changing climate and ways to fix it. And their conclusion very well could enter into the debate on climate change.
Critics acknowledge the existence of today’s changing climate but contend it’s driven by earth’s cycles over time – like the Medieval Warm Period – instead of human activity.
“Our study is yet one more piece of evidence that is a hokey argument,” Briner said.
The team used a first-of-its-kind dating technique to prove Greenland was just as frigid at the time of the Vikings’ 10th century landing as when they mysteriously vanished from the world’s largest island several centuries later.
The findings reject conventional theories suggesting the Medieval Warm Period allowed for the Viking landing from nearby Iceland and that the ensuing “Little Ice Age” – around 1300 – later froze them out.
Briner – and his diary-keeping Ph.D. student Avriel Schweinsberg – collected rock samples from Greenland and the nearby Baffin Island in northern Canada in 2012 and 2013 showing moraines – deposits left behind by moving glaciers – dated to the time period when the Vikings occupied the island. That means it occurred at the same time the glaciers were in their farthest advance.
That proved it was as cold as ever on Greenland all the while Europe enjoyed a three-century period with an unusually warm climate.
“It’s becoming clearer that the Medieval Warm Period was patchy, not global,” said Nicolás Young, the lead author of the study.
Young is a glacial geologist at Columbia University’s Lamont-Doherty Earth Observatory. He earned a Ph.D. in geology from UB in 2012 under Briner’s tutelage.
“Climate change has a lot of spacial complexity,” Briner added. “That’s an example of it may be warmer on one side of the earth and not on the other.”
Why does that matter? And, what’s so different now?
“Today, there’s warmth over the vast majority of the surface of the earth,” Briner said.
Rocks collected in Greenland and Baffin Island were analyzed in Buffalo and in a Columbia University laboratory of another co-author, Joerg Schaefer, using an emerging technique that measures certain radioactive isotopes in order to determine when the glaciers deposited the moraines. The laboratories are among just a few capable of precisely analyzing samples as young as 1,000 years old.
“This particular method we used is sort of a step forward,” Young said. “In part, that’s what we’re most excited about.”
The process is started by cosmic rays that constantly bombard the Earth from space.
As they’re become exposed by receding glacial ice, Briner said, the chemical composition of the rocks are then altered by those rays.
“The Beryllium isotope in rocks that tell us its age,” Briner said. “They build up in the rocks through time.”
“The more isotopes in the rock, the older it is.”
It’s not an easy endeavor to study the Arctic.
Access is limited. The conditions can be harsh. And sunlight is seasonal.
When’s the best time of year to study?
“May, when the semester ends,” Briner said. “And, it’s kind of a shame because Buffalo is just blooming. It’s a return to winter.”
Briner has come a long way since his first expedition as a doctoral student to Baffin Island in 2000.
There’s no tourism on that island, so he said access is gained by a small, propeller-driven air flight.
Then, it’s finding a place to stay – or a place to pitch camp – among the almost entirely Inuit population of about 11,000.
“You knock on doors and make it happen,” Briner said.
Once on location, snow machines are the transportation used to “zip across the ice-covered fjords” and up the valleys into the mountainous terrain, Briner said. Ice 6 to 7 feet thick can cover water that’s 300 feet deep in places.
Since his first trip, Briner made contacts in the native communities, some of whom speak English, who offer hunting and fishing cabins for lodging.
Getting to Greenland is a little different.
Funding though the National Science Foundation helps the expedition board C-130 military aircraft out of an Albany-area base to Greenland. Then, they travel by helicopter into the study areas.
To this point, the field work for Briner and Young’s team has been focused in western Greenland in annual trips dating back to 2008.
After this latest research project, the pair are collaborating on a pair of other projects in different areas of the island.
“If we can understand how glaciers thin and grow over time,” Briner said, “we can have a monitor of global climate change.”
Past and future
The political debate over climate change rages on around them as scientists like Briner, Young and others are determined to continue documenting the landscape, collecting samples, analyzing data and publishing results.
But that doesn’t mean these scientists don’t have strong opinions about climate change.
Many scientists, environmentalists – and most recently, Pope Francis – charge the rapidity of the current global warmup is driven by a sharp rise in greenhouse gases that increased steadily following the industrial revolution. That, they argue, puts the globe on a precarious trajectory for a rapid rise in sea level and more extreme weather patterns that can lead to stronger storms, drought, famine and a host of other perils.
Some skeptics discount the theory altogether, suggesting climatechange today is driven by earth’s cycle.
Briner’s team study disputes that. Because they’ve been on the ground – and the ice – they say they’ve witnessed the effects of what climatological data indicates is a warming Earth.
Ice has receded by fractions of a mile to miles in some areas. That melting has a direct correlation with the rise in global sea levels.
“You can look high on the valley walls and see how high the ice used to be,” Briner said.
“On Greenland, they have so much melt water coming off, the rivers have huge floods. Some of the native communities are starting to feel the impacts from the rivers.”
What do they expect to see on Baffin Island and Greenland in future trips?
Briner said, “less ice for sure.”