Reduce Arctic soot to prevent more warming, scientists urge

The haze which you see sometimes in the spring may be the result of agricultural fires in Canada’s western provinces, which also contribute to Arctic warming. (PHOTO BY JANE GEORGE)

Fires, diesel-burning power generators, trucks and ships: they’ve all got something in common.

That’s their ability to generate soot in the Arctic, which accounts for as much as 30 per cent of the warming in the region.

“It’s an Arctic problem,” said Andreas Stohl from the Norwegian Institute for Air Research at last week’s Arctic climate change and pollution conference in Copenhagen.

Finding ways to limit soot production in the Arctic is likely to be on the agenda of this week’s Arctic Council meeting in Nuuk.

That’s because the Arctic nations, including Canada, the United States, Denmark, Iceland, Norway, Sweden and Finland, can curb some Arctic warming simply by reducing soot in the Arctic.

And that will provide the Arctic some relief from rising temperatures, while the world’s nations take their time on reaching an agreement to slash greenhouse gas emissions.

“It wouldn’t solve the issue of climate change,” Stohl told Nunatsiaq News. “But you can still do something.”

For example, the shipping industry could retrofit its vessels with “relatively cheap” exhaust filters to catch tiny airborne soot particles; Arctic communities could also look at other ways to generate electricity than diesel-burning generators and turn to incineration instead of open burning to dispose of trash.

“It could make a difference,” Stohl said. “If you’re careful, it could reduce the local impact.”

Locally, these efforts would “dramatically” reduce soot, Stohl said — and these efforts could cut down on warming in the Arctic, particularly around communities which may not realize how much soot contributes to heating up the lands and waters in the Arctic.

It could be possible to reduce Arctic warming down, if these local causes of heat are reduced, Stohl said.

The impact of soot on the climate doesn’t last as long as the warming from greenhouse gas emissions — only up to a month at most.

But soot which originates in the Arctic has a powerful, “very, very important” impact, Stohl said.

With shipping and cruises expected to increase in the region and spew out more soot into the air, there’s an urgency to act on soot reduction, he said.

Ships, open burns and anything that runs on diesel fuel are the major producers of soot in the Arctic.

But other major producers of soot within the Arctic include gas and oil burning at natural gas plants and wells or along pipelines.

Reducing the level of soot in the air could also improve human health, because soot particles are known to trigger asthma attacks.

Here’s how soot works:

Surface soot falling from the air darkens snow and ice, which then absorb more of the sun’s rays.

As the surface warms, snow and ice crystals then merge into larger structures, which absorb even more warmth and speed the pace of melting.

As the snow and ice melt, the soot often stays on the surface where it continues to more absorb heat and cause even more melt.

The water and land exposed by the melting snow also absorbs additional heat, particularly in the spring when the sunlight is increasing and seasonal snow melt is already underway.

Soot also comes to the Arctic from the South. Soot-laden smoke from agricultural or forest fires can stay in the atmosphere for about a week, where it leads to thicker, warmth-catching clouds,

These fires have taken place for thousands of years, but their smoke may be traveling further north than before, due to warming in the Arctic.

That’s because smoke plumes travel best when the temperatures in the place they’re produced and their final location are similar.

Because Arctic temperatures have risen and are now sometimes similar to spring temperatures far to the south, ideal transport conditions for smoke produced by agricultural fires are probably more frequent.

Canada does have rules for agricultural fires, which vary by jurisdiction.

But their goal is largely to limit the impact of the fires on air quality and surrounding property, while still allowing burning to take place.

The timing of these agricultural fires — early spring — means the smoke comes north during the most vulnerable period for snow and sea ice melt.