Leaps in technology are making it easier to build structures with fewer negative impacts and potentially reduce climate change, but more must be done to accelerate their widespread use.
Increasing attention is on embodied carbon-amounts of CO2 emitted during the production and life cycle of building materials. For commercial buildings, this is primarily the concrete and steel making up the structure and sub-structure, which typically account for more than 50% of the embodied carbon footprint. And studies from NOAA’s Global Monitoring Lab indicate that CO2 alone is responsible for about two-thirds of the total heating influence of all human-produced greenhouse gases.
Fortunately, according to Deloitte’s recent report, businesses are increasingly committing resources toward sustainability. “If there was any doubt that climate change is an enduring part of the business agenda, the increased focus on sustainability by leaders over the past year should put it to rest,” says Deloitte Global CEO Joe Ucuzoglu. “The path forward will take time, it will require businesses investment, and it will be driven by new and innovative technologies and creative approaches.”
Fueled by business leaders with the leeway for-even pressure toward-sustainable construction, we may be witnessing a rapid sea-change in innovative green building materials like mass timber and carbon-negative concrete. If supported quickly enough, these tech advancements will provide a significant and positive impact on climate change.
Mass Timber’s Promise
Although the concept has been around for more than 30 years, technology to transform sustainable timber is one such innovation that may have finally hit its tipping point. Mass timber or cross-laminated timber (CLT) is engineered by gluing or nailing together sheets of wood in cross-grain patterns and treating them with flame retardants to yield a building material that is stronger and more fire-resistant than traditional wood.
It’s a renewable, recyclable and biodegradable choice for low-carbon construction because it reduces the energy, resources and emission-heavy impacts of producing concrete or steel. Using mass timber also reduces harmful post-construction chemicals released (outgassing) common to steel and traditional concrete. And during growth, trees farmed for production are naturally absorbing and removing carbon from the environment and supplying us with oxygen. There are other environmental impacts from CLT, but, with proper forestry management, I believe the benefits of replacing steel and concrete with mass timber outweigh the potential downsides.
American construction projects lag behind other countries using fabricated timber. According to the Council on Tall Timber and Urban Habitat, the rise of multistory buildings using new timber technology dates back to Swedish construction in the early 2000s. But the dam may have broken allowing for much wider use in the U.S. as more insurance companies cover it and U.S. agencies are restructuring building codes to accommodate CLT construction. In 2021, New York City approved CLT in up to six-story construction (up to 85 feet), and late last year, California updated codes to allow for up to 18 stories built with it.
According to the industry association WoodWorks, more than 1,600 projects in the U.S. were built or are being designed with mass timber, and Milwaukee, Wisconsin, now boasts the world’s largest. At 25 stories tall, the $80 million luxury high-rise called Ascent opened last year featuring mass timber made from sustainable, fast-growing forests in Austria.
The impacts may take generations to realize, but by acting today and betting on the long game, mass timber could cut 14%-31% of global CO2 emissions and 12%-19% of global fossil fuel consumption, according to one 2014 study. And, although it seems unattainable today, almost 8 billion tons of CO2 emissions could be cut by 2050 if 90% of new urban buildings were constructed with mass timber.
Carbon-Negative Concrete’s Future
Mass timber won’t fit every application, like highway overpasses, so improving how concrete is made is an important pursuit. Concrete is one of the most widely used materials in construction due to its strength and durability; however, producing concrete is incredibly energy-intensive and releases large amounts of carbon dioxide into the atmosphere. Due in large part to the energy and resources needed to turn clay and limestone into cement, the binder in traditional concrete, scientists estimate global production of concrete contributes as much as 8% of the world’s CO2 emissions.
With another 2 trillion square feet of new building space expected by 2060, it’s time to deploy better concrete. Researchers have developed new forms of concrete that absorb more CO2 than they emit during production—what is known as “carbon-negative” concrete—often by replacing traditional cement with an alternative like bioengineered components. Innovative researchers at the University of Colorado Boulder say they have the tools and technology to cut two gigatons of CO2 released annually and permanently sequester more than 250 million additional tons into bioengineered concrete. They are cultivating calcareous microalgae—like those that produce coral reefs—for use in biogenic limestone, which could eventually eliminate the need for destructive limestone mining and the emissions from baking and pulverizing it into cement.
Fly ash (a byproduct of coal-fired power plants) is another cement substitute, and crushed recycled glass or steel slag (a waste byproduct of steel production) is replacing sand or gravel as the aggregate in concrete, all of which reduce impacts from material creation and harmful waste sent to landfills. Innovators like Blue Planet and CarbonCure are advancing these new technologies to extract CO2 from various waste products and mineralize it permanently, keeping it from reentering the atmosphere.
The Changing Tide
These advances just scratch the surface but offer immense potential to mitigate climate change. And, following the uncommonly swift pharmaceutical research and approvals that stemmed the effects of Covid, construction industry leaders and regulating agencies should consider rapidly adopting these and other sustainable technologies to stem the human environmental impact.
The materials forged for construction today could last centuries, even longer in some crumbling form. And, with each passing year, we may miss the opportunity for maximum effect from new innovations. Making a speed to acceptance supremely important.
Source: forbes.com