Better Forest Management, Wooden Buildings Would Lower Carbon Emissions
July 2, 2020
As scientists continue to warn about projected climate change on a heating planet, others are taking steps in their own realms to mitigate the damage in innovative ways.
A recent webinar hosted by Grow Smart Rhode Island illustrated the connection between forest health and new wood-construction technologies in a combination that can significantly reduce carbon emissions.
Presentations by Frank Lowenstein, deputy director of the nonprofit New England Forestry Foundation (NEFF), and David Odeh, principal at North Providence-based Odeh Engineers Inc., highlighted the “We Need the Forest to Fight Climate Change” discussion. While they provided different areas of expertise, they connected on the central issue: Proper forest management and innovative construction using new wood products will lessen carbon emissions.
Lowenstein, who has been with the Littleton, Mass.-based NEFF for more than two decades, issued an oft-repeated warning: “We will see enormous damage from climate change with each increase above 1.5 degrees Centigrade by 2030. The damage increases with each point-5 percent.”
He noted that the difference between a 2 percent and a 3.1 percent temperature increase would cause more than $40 trillion in damages by the end of this century.
“We’re already seeing the extremes of this with flooding, heat, fires, storms, hurricanes,” Lowenstein said. “It will only get worse unless we take steps to avoid it, and the best use of forest can help with this.”
Lowenstein told the June 24 webinar audience that conserving forestland and managing growth properly, including the sustainable harvesting of timber, will help store greater amounts of carbon. Conversely, he said, failed management will lead to worsening climate emissions.
“Trees store carbon,” he said. “It’s that simple. Sustainable harvesting is critical. This requires that architects, engineers, and planners must include sustainability in their construction plans.”
Odeh agreed with Lowenstein’s assessment and shared information about new construction methods that allow wood products to be used in buildings up to 85 feet high. He focused on what are known as heavy-timber products, essentially long wooden planks that are fused together to produce a sturdy construction product.
Illustrating the techniques used in a 6-story dormitory recently completed at the Rhode Island School of Design in Providence, which Odeh Engineers worked on, Odeh noted that building codes are being adjusted to reflect these new technologies.
“With new categories of heavy timber,” he said, “the approved height of buildings could reach 270 feet.”
He noted that the wood used in such construction must be covered for fire protection, but depending on the height of the building, some or all of the wood could be exposed for aesthetic purposes. Viewed from above, the heavy timber floors used in the RISD dorm resemble super-wide hardwood floorboards. The ones employed in that North Hall project stretched the full length of the building.
These products include glued, laminated timber and structurally composite timber, both adopted in the mid-20th century. Newer forms of what Odeh called “panelized wood” include cross-laminated timber (CLT) and dowel-laminated timber.
“They are remarkably strong products made from green lumber and can be joined in long lengths,” Odeh said. “These mass timber paneled products can be manufactured in lengths up to 65 feet for floors, walls, and roofs.”
Odeh noted that heavy-timber construction is not new, as illustrated by early Industrial Revolution-era mills in New England built with huge timbers and brick. He and Lowenstein said modern heavy-timber products reduce carbon emissions both during construction and for the life of the building.
“Wood buildings help with housing equity, lower emissions in construction, and sequester carbon,” Lowenstein said. “There are projections that CLT could support buildings of up to 18 stories, but certainly we are seeing structures ranging from 6 to 12 stories.”
Increased use of new wood products like CLT, Lowenstein added, can become part of systematic plans for forest maintenance and conservation. He said using newer tree growth for green timber during construction allows older trees to mature so that they offer maximum environmental benefit. He said policymakers need to incorporate that kind of forest management and support it with financial incentives for landowners who hope to generate revenue from forestland.
“Right now we have no policy of support for landowners,” Lowenstein said. “They are not going to wait forever, and there is a lot of pressure for them to sell forestland.”
With the proper outreach and education and some financial incentive, landowners could manage their forest property and achieve some revenue at the same time through a payment policy of some kind, according to the presenters.
“Private landowners need to agree to longer periods of time between harvests, but how do we bridge the gap?” Lowenstein asked. “Tax incentives or carbon storage payments would help.”
John Pantalone is an associate professor and department chair at the University of Rhode Island’s Harrington School of Communication and Media.