Canadian Manufacturing

Dow, Nature Conservancy plan calls for trees to curb pollution

by Ramit Plushnick-Masti, The Associated Press   

Cleantech Canada
Manufacturing Cleantech

A recent Dow report says the cost of cleaning a ton of nitrogen oxide with reforestation was about the same as using traditional equipment

FREEPORT, Texas—One of America’s largest chemical companies and one of its oldest conservation groups have forged an unlikely partnership to curb pollution by recreating the forest that once dominated the Texas landscape.

Dow and the Nature Conservancy began a six-year, US$10-million collaboration in 2011, when they came together to look at ways natural resources could be used to save the company money.

The plan drafted by Dow Chemical and the Nature Conservancy is only in its infancy and faces many hurdles.

But most plants, and especially trees, capture pollution naturally when it hits their leaves. Trees with the biggest leaves and the widest canopies capture the most pollutants, especially nitrogen oxide, a common byproduct of combustion that irritates lungs and contributes to ground-level ozone.


After reading an obscure notation by the federal Environmental Protection Agency that suggested reforestation could improve air quality, the two groups decided to research how the idea might work and whether it could be cost-effective.

Scientists used a complex model from the U.S. Forest Service that considers everything from wind patterns to the size of tree leaves and the overall canopy to estimate the air-quality improvements that might come from 400 hectares of forest.

“The big discovery was that you could combine the traditional infrastructure with reforestation and still meet regulation,” said Laura Huffman, the conservancy’s director in Texas.

The trees, Huffman said, may not completely replace technology. But they could complement it, allowing factories to use smaller, cheaper equipment.

The research found that over 30 years, a 400 hectare forest would remove up to seven tons of nitrogen oxide annually. Timm Kroeger, a senior environmental economist with the conservancy, says a mechanical “scrubber” removes about 50 to 70 tons annually.

So a 4,000 hectare forest equals one average industrial scrubber. And in this part of Texas, where open land is ample, reforestation is within reach.

The cost of the project, not including the land, would be about the same as using traditional forms of pollution control, Weick said.

Organizers hope to work with a landowner interested in reforesting, probably with help from conservation tax credits. Alternatively, the Nature Conservancy or the federal government would buy the land and give it to Dow free of charge.

A recent progress report determined that the cost of cleaning a ton of nitrogen oxide through reforestation was $2,400 to $4,000, compared with $2,500 to $5,000 using traditional equipment.

The research is still being reviewed by other scientists. It would also have to win approval from state and federal regulators—who would require any pollution-cleansing method to be quantifiable and enforceable.


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