What about warming?
Does burning biomass raise the level of carbon dioxide in the atmosphere? It’s an important question in the ongoing biomass debate because many believe CO2 — a “greenhouse gas” — contributes to global warming, which they further theorize will cause environmental havoc, with perhaps catastrophic results.
It seems like a simple question. Oxidation — whether it’s rust, rot or combustion — always produces two end products: carbon dioxide and water.
But that hasn’t stopped the debate. Many environmentalists and most governmental environmental authorities promote the burning of biomass, calling it a plentiful source of renewable energy.
They say biomass burning is “carbon neutral” — that it doesn’t raise levels of CO2 in the atmosphere because the fuel is part of a very short-term cycle. Yes, burning wood releases CO2, but it’s almost immediately taken up by new trees.
This is substantially different, they say, from the result of burning fossil fuels. While both processes produce CO2, burning fossil fuel releases carbon that has been stored (“sequestered”) for millions of years. That adds to the long-term level of CO2 in the atmosphere.
In a recent statement, the Washington Department of Natural Resources said, “The carbon that is released through the conversion technology (combustion) is balanced by the reabsorption of carbon by the forests. That’s why both federal and Washington state policy has viewed the utilization of forest biomass as carbon neutral.”
Some critics have suggested the additional emissions required to transport the biomass may tip the CO2 scales away from its use. The DNR has a ready answer for that, too, saying recent research by the Olympic Region Clean Air Agency suggests, “There are still fewer greenhouse gas emissions from forest biomass used to produce energy than if the forest residuals were to either be left on site to biodegrade … or burned on site.”
Nippon Paper Industries mill manager Harold Norlund explained the DNR’s conclusion, saying that biomass left in the fields also releases carbon dioxide as it degrades. The process further produces substantial amounts of methane, an even more potent greenhouse gas, he said.
Bonnie Phillips, former executive director of the Olympic Forest Coalition, provided a different point of view. “In the end, burning wood will generate more CO2,” she said. While “the government and the industry tout biomass as carbon neutral … unfortunately this is not the case ….
“The problem here is that it will take 40–60 years to recapture (and sequester) the amount of carbon burned, and climate scientists say we must reduce greenhouse gases now.”