Mass timber construction is on the rise, with advocates saying it could revolutionize the building industry and be part of a climate change solution. But some are questioning whether the logging and manufacturing required to produce the new material outweigh any benefits.
The eight-story Carbon 12 building in Portland, Oregon is the tallest commercial structure in the United States to be built from something called mass timber.
If the many fervent boosters of this new construction material are right, however, it is only one of the first mass timber buildings among many, the beginning of a construction revolution. “The design community in Portland is enthralled with the material,” said Emily Dawson, an architect at Kaiser + Path, the locally-based firm that designed Carbon 12.
Among architects, manufacturers, and environmentalists, many want nothing less than to turn the coming decades of global commercial construction from a giant source of carbon emissions into a giant carbon sink by replacing concrete and steel construction with mass timber. That, they say, would avoid the CO2 generated in the production of those building materials and sequester massive amounts of carbon by tying up the wood in buildings for decades or even longer, perhaps in perpetuity.
Beverly Law, a professor of global change biology and terrestrial systems science at Oregon State University who headed up the Oregon forest study, says there hasn’t been a thorough analysis of carbon emitted by mass timber production because it is enormously complex to track the factors that produce CO2 in forest ecosystems and in production. Some of the data needed, she said, is incomplete or absent. It took her team of researchers more than a decade of analysis to figure out that the Oregon wood products industry was the largest emitter of CO2 in the state, Law said.
Such industrial-type forestry — large-scale plantings of trees selected to grow fast — creates a “biological desert,” said Talberth, of the Center for Sustainable Economy. “And it’s driving the extinction of thousands of species. Mass timber is mass extinction.”
“We must ensure that mass timber drives sustainable forestry management, otherwise all of these benefits are lost,” agreed Mark Wishnie, director of forestry and wood products at The Nature Conservancy. “To really understand the potential impact of the increased use of mass timber on climate we need to conduct a much more detailed set of analyses.”
Source e360 yale