We associate air pollution with big cities, but millions of people are feeling the impacts of pollution from wildfires burning from California to Alaska and as far east as Colorado.

It is one of the worst years on record for forest fires and we will spend billions to fight the fires and protect people, homes and businesses.

Mammoth forest fires have been around for centuries.  In a single week in September 1902, theYacolt Burn engulfed more than a half million acres and killed 56 people in the Columbia River Gorge and around Mt. St. Helens. The choking smoke was so thick that ships on the Columbia River were forced to navigate by compass and the street lights in Seattle, 160 miles to the north, glowed at noon.

Triggered by a mild winter and low snow pack, this year’s fire season is earlier than normal and could be devastating.  Just as damaging, these fires are releasing millions of tons of carbon dioxide, a greenhouse gas, into the atmosphere.

Last month, The Vancouver Sun published a Sierra Club analysis showing that, over the last two decades, British Columbia forests have turned from a big absorber of CO2 into a big emitter of CO2.

Between 2003 and 2012, BC’s forests emitted 256 million tons of CO2 into the atmosphere.  In the previous decade, healthy trees actually absorbed 441 million tons of CO2 from the atmosphere.

The main culprit identified by the Sierra Club is the tiny pine beetle. Trillions of these beetles are suffocating healthy growing trees.  Even though the infestation peaked a decade ago, it has turned millions of acres of once lush green forest into a barren moonscape.

Huge swaths of central B.C. and parts of Alberta have been hit so badly that dead and dying forests cover nearly 100,000 square miles.  The Sierra Club wants the British Columbia provincial government to invest more than $1 billion to improve the health of the public forests by reducing clear cuts and focusing harvest levels and fees on carbon storage.

The Sierra Club wants the government to curtail harvests of mature trees, which they say store the most carbon.  But those are the trees most affected by the beetles.

Removing those dead and diseased trees and replanting is the best way to maintain a healthy growing forest that stores carbon and emits oxygen.  In addition, clearing dead trees and debris from the forest floor reduces the risk of massive wildfires that pump millions of tons of CO2 into the air.

President George W. Bush proposed a similar healthy forests initiative a dozen years ago, but groups like the Sierra Club roundly criticized the program as just a way to increase logging in public forests.

On its website, Weyerhaeuser illustrates how growing forests absorb carbon dioxide, store the carbon and emit the oxygen.  When harvested, the carbon remains in the lumber and wood products we use and recycle every day.

Nowhere is the contrast between managed forests and barren forest land clearer than in Mount St. Helens.

After the 1980 volcanic eruption, Weyerhaeuser salvaged 68,000 acres of its damaged trees inside the blast zone and replanted 19 million trees.  In the adjacent 110,000 acre Mount St. Helens Volcanic Monument area, the decision was made to just let nature take its course.

The result?   The unmanaged land remains barren, with alders, willows and some fir growing in stream beds. Meanwhile, Weyerhaeuser’s managed forest is flourishing and reducing greenhouse gases – something barren land cannot do.

Sierra Club, take note: when it comes to pine beetle infestations or massive wildfires, letting nature take its course is not always the best course of action.