THE FORECAST CALLS FOR CHANGE
Increasing year-to-year variability in the environment is one of the biggest changes we have been seeing in Atlantic Canada, according to a senior oceanographer with DFO.
This includes not only the temperatures, but things like variability in the freshwater outflow, and the amount and timing of ice coming out of the Arctic, says Dr. Pierre Pepin, who has studied climate change and population dynamics for most of his career.
Pepin stresses the difference between climate and the weather when discussing climate change.
He feels often people have a tendency to assign whatever is happening in a particular weather system to climate change, but advises that it is probably a combination of climate change and weather.
Variability, Pepin explains, refers to how much the weather can vary from a designated period of time to the next. Increasing variability means it has become more difficult to predict the weather based on precedent, as well as an increase in the occurrence of extreme temperatures and weather events.
“Generally, in the past, you could say if last winter was harsh, you could say this winter was going to be not that different,” he explained. “Well, now, it’s becoming much more difficult to say how similar or different the winter from one year to the next will be.”
For example, winter surveys in recent years have found a fair bit of cold water in the Gulf of St. Lawrence but nothing unusual, Pepin says. However, this year, they have found the greatest amount of cold water in the Gulf of St. Lawrence in 24 years.
According to Pepin, what has made the moderate-term forecast more unpredictable is an increase of energy, created by global warming, in the system.
“Those kinds of moderate-term forecasts are a lot harder to come by because there’s more energy in the system, because the planet is warming there’s more energy in the system,” he explained. “And when you have more energy in the system, your ability to predict how what happens in one part of the world will influence what happens in your part of the world becomes more difficult.”
Dr. Norm Catto, head of geography at Memorial University in St. John’s, agrees.
Catto said the increasing weather variability that Atlantic Canada faces is going to be harder for the public to deal with than climate change itself.
For example, he explains that if you knew every year was going to feature less snow than the last, then you can prepare accordingly for that.
But that’s not how climate change works.
Instead, the amount of snow we receive each year may fluctuate: one winter may feature heavy snowfall while the next there may be none.
It’s entirely unpredictable.
That’s going to make adapting more difficult for businesses who depend on the snow, for example, or towns who are trying to budget how much to spend on snow clearing.
BELOW: A tour boat approaches an iceberg in 2018 off Newfoundland’s Northern Peninsula.
ABOVE: Dr. Pierre Pepin is senior oceanographer with Fisheries and Oceans Canada.