Jennifer Francis: An Interesting Fall and Winter
September 26, 2012
If you saw the current sea ice video, you saw part of my recent interview with Rutger’s Jennifer Francis, whose research is helping fill in the blanks on how an increasingly ice free arctic affects us in temperate zones around the planet.
I’m breaking this interview up into bite size pieces – this first one dovetails nicely with a recent report on NPR comparing the loss of arctic sea ice to the less discussed melt back of snow coverage – particularly in the spring time. Watch Dr. Francis above describe the effects of such a process, as compared to arctic ice, – only a minute or two, then check the
All Things Considered story here:
Arctic sea ice is in sharp decline this year: Last week, scientists announced that it hit the lowest point ever measured, shattering the previous record.
But it turns out that’s not the most dramatic change in the Arctic. A study by Canadian researchers finds that springtime snow is melting away even faster than Arctic ice. That also has profound implications for the Earth’s climate.
Springtime snowmelt matters a lot: It determines when spring runoff comes out of the mountain to fill our rivers. And Chris Derksen at Environment Canada in Toronto says snow also reflects sunlight back into space, helping to keep the Earth from heating up too fast.
“When you remove the snow cover form the land surface, much as when you remove the sea ice from the ocean, you take away a highly reflective, bright surface, and you expose the bare land or tundra underneath, and that absorbs more solar energy,” he says.
That darker land traps heat and warms the planet. Scientists have been keeping an eye on this trend for years.
But Derksen and colleague Ross Brown have produced a study, which has been accepted for publication in Geophysical Research Letters, that documents a dramatic increase in the speed of this snowmelt. It turns out that in May and June, snow across the far north is disappearing fast.
“We’re now losing spring Arctic snow cover at a rate faster than the models predict,” Derksen says. And that “puts somewhat into question what the scenario will look like 10, 20 or 30 years from now.”
Even today, the early spring snowmelt is of concern to biologists who study life in the far north. Syndonia Bret-Harte at the University of Alaska, Fairbanks, says this change affects the rivers that spawning fish rely on.
It also hastens melting of the permafrost, a layer of frozen soil that contains a lot of carbon. And when permafrost melts, it releases those greenhouse gases into the atmosphere. And then there’s the matter of fires in the boreal forests.
“If things dry out faster in the spring, then you can get more fires, and that’s another trend we see in recent years, is increased fire frequency and also the size of fires,” says Bret-Harte.
And while the far north is feeling these effects most strongly, she says they affect us, too.
“Since the Arctic acts as the air conditioner … for the rest of the Northern Hemisphere, heating up in the Arctic is also probably going to cause feedbacks to heating up in the more southern climate