Cutting trees to cool the planet?

In a twist, a new study suggests that regularly logging forests can quadruple the amount of carbon dioxide soaked up from the atmosphere.

The trick is to use the harvested wood in place of steel and concrete during the construction of new homes and buildings and replant the forest with fast-growing, carbon-soaking trees.

"When you think about how you reduce your carbon footprint, you have to look at the whole system," Elaine Oneil, a research scientist in the School of Forest Resources at the University of Washington, told me today.

She and colleagues compared life cycle, or so-called cradle-to-grave, analyses of wood products and other materials used in the construction industry.

These analyses assess the environmental impacts of all stages of a product, including materials extraction, energy for processing and manufacturing, product use and disposal.

The comparisons showed, for example, that replacing steel floor joists with engineered wood joists reduces the carbon footprint by almost 10 tons of carbon dioxide for every ton of wood used. Using wood flooring instead of concrete slab flooring reduces the carbon footprint by approximately 3.5 tons.

"We are not going to live in a hole in the ground," Oneil said. "We are continuing to develop and build houses." The analysis, published this June in Carbon Management, helps people determine the most environmentally friendly way to do move forward, she added.

The concept of life cycle analysis isn't new, but collecting the data to perform them is painstakingly slow (the Carbon Management study is a synthesis of 15 years of data). As policy and decision makers look to the future, Oneil says, these types of analyses will be important.

The choice of what product to use may still come down to cost, she noted, but by including the impact of each product on things such as carbon or water quality makes the choice more informed.

Not applying life cycle analysis can lead to unintended consequences, the study's lead author Bruce Lippke from the University of Washington notes in a news release.

For example, looking at just the carbon lost when wood products are disposed of through burning or being sent to landfills has led to incentives not to cut trees in the first place.

"What's missing in the analysis and policymaking," he said, "is how much carbon dioxide can be kept out of the atmosphere by using wood products instead of those that take fossil fuels to produce."