Carbon dioxide in our atmosphere is more than four hundred parts per million, a concentration greater than at any time in the last three and a half million years. Back then, mid-Pliocene, there was little ice at the earth’s poles and sea level was sixty feet higher.
Those who do not accept that humankind has passed the environmental tipping point place great hope in carbon capture and sequestration. CCS, in simple terms, means capturing CO2 and burying it deep underground where it cannot escape for many millennia. (Kinda like all the methane gas below rapidly-melting tundra.) Carbon-dioxide removal doesn’t just slow or stop the increase of CO2, it reduces it. Skeptics warn that forcing carbon underground will increase earthquake activity. (See fracking.)
One way Nature captures and stores carbon is with trees. Protecting forests from development and proper management — keeping forest floors neatly raked — will keep the trees sucking CO2 from the atmosphere. Increasing the use of wood for construction will reduce carbon emissions. Building codes typically limit wood construction to five stories. Advancements in engineered lumber, specifically cross-laminated timber (CLT), allow for taller wooden buildings.
Production of building materials such as steel and concrete account for eleven percent of the world’s carbon emissions. Lumber is still storing carbon that otherwise would be released when trees die and decompose. CLT is as strong as steel or concrete but weighs eighty percent less. Wooden buildings also fare better in earthquakes.
Some time ago while driving in Portland I was surprised to see a wood building under construction. It was taller than any wood building I had ever seen. Named Carbon12, the eight-story luxury-condominium building built of CLT recently opened in a rapidly-gentrifying neighborhood in north Portland. Oregon is the first state to allow wood buildings taller than six stories. The state’s lumber industry would also benefit from increased wood building. Framework, a twelve-story office/residential tower recently received permits for construction in Portland’s trendy Pearl District. The project is presently on hold for financing.
Can cross-laminated timber save us from a warming planet?
