Canadá

Icebergs moving from Greenland to Newfoundland slowing dramatically by end of century, researcher says

The arrival of icebergs in Newfoundland and Labrador ushers in spring and brings tourists in droves to coastal towns such as Bonavista.

On a cold, rainy June day, about a dozen adventure seekers set out on the Lady Marguerite, a 14-metre tour boat owned and operated by Derm Hickey, a retired fisherman.

“The tourism is a great boost to Newfoundland, to all the little outports and the city, too,” said Hickey.

But within this century, climate change could threaten the annual migration of the ice behemoths, according to the latest research.

The icebergs off Newfoundland “calve” — or break off — the western side of the Greenland glacier.

A study published on Jan. 1 in the U.S. Proceedings of the National Academy of Sciences found the “deglaciation of Greenland” is resulting in ice melting four times faster than previously thought. That has prompted Memorial University glaciologist Lev Tarasov and his colleagues to study the relationship between glaciers and climate change.

Tarasov is the sole Canadian among a group of international scientists working on the Ice Sheet Model Intercomparison Project (ISMIP), the results of which will be presented to the International Panel on Climate Change (IPCC) later this year.

Tarasov’s work is specifically on the Greenland ice sheet. By boring down into the layers of ice, he said, scientists can tell that there was little change in the Greenland ice sheet between the mid-1900s to the turn of the 21st century. At that point, however, rapid melting began, he said.

More melt could mean more icebergs in the near term, but fewer in the future, he said.

“By the end of the century, we’re going to have less icebergs coming from Greenland. There’s also going to be more melts in the Labrador Sea, so that might mean less and less icebergs making it to St. John’s.”

The Greenland ice sheet, measuring 1.7 million square kilometres, extends beyond land and over the sea. But when it melts back to where it sits on land, that is where the ice will melt, he said.

“That ice will not form icebergs because they are not in the water.”

Tarasov said warmer ocean temperatures below the ice sheet will cause even faster melting, and those rising sea levels will cause coastal erosion.

Planning for an uncertain future

The impact of climate change, including on water levels and coastal erosion, is of great concern to Joe Daraio, a hydrotechnical engineer at Memorial University who specializes in designing infrastructure to adapt to adverse events.

“We have a lot of coastal towns in Newfoundland and Labrador … So how do we design a bridge crossing, a culvert to carry the largest possible flow?”

Daraio has received funding from Natural Resources Canada to train engineers working with the provincial government to factor climate change projections into their designs.

“The assumption is that the future is going to be like the past when we do our designs, but that’s not the case with climate change. If we have a design life of 50 years, in 50 years the climate is going to be very different.”

The engineering profession is just starting to incorporate climate change in a more systematic and rigorous way, said Daraio.

Sea level rise will force migration

​Tarasov said the impacts of rising sea levels globally on human migration are his “nightmare scenario.”

“There’s millions of people living within a metre of sea level. So a one-metre rise of sea level is possible within our best models right now by the end of this century,” which would force those people inland.

When you consider some of this ice took 100,000 years to form, roughly 80 years is a short period before it could all disappear, said Tarasov.

Redes Sociais - Comentários

Fonte
CBC
Tags
Mostrar mais

Artigos relacionados

Back to top button

Close
Close