When broken down by sector, Building Materials and Construction represent 11% of all greenhouse gas emissions. For context, the rest of the sectors are Industry (30%), Building Operations (28%), Transportation (22%), and Other (9%). Building Material and Construction emissions are intrinsically tied to the steel and concrete industries, which each respectively emit around 8% of all greenhouse gas emissions. In the United States, outside of residential homes, almost all of our buildings are made from those two materials. One reason for this is the strength of those materials. Another is because they helped heal a wound in our psyche caused by the Great Chicago Fire of 1871 when numerous wooden buildings were burned to the ground. But 150 years onwards, with the climate crisis pressing down upon us, tall wood buildings are once again on the rise in North America. They represent a lower-carbon alternative that can reduce our reliance on steel and concrete. The construction industry calls it mass(ive) timber and it’s actually been popular in Europe for almost 30 years now. The technique involves glueing or laminating smaller dimensional lumber into epically sized panels and beams which can then be used to construct buildings up to at least 18 stories high. David Roberts has an excellent overview of mass timber and this NYT article is also worth a read. It’s not the only solution for decarbonizing the Building Materials and Construction sector but is one that has gained substantial traction in the last 5-10 years.
Many words have been written on the exact means by which mass timber can reduce the embodied carbon of our buildings. What I’m interested in is how mass timber illustrates some common themes across the climate solutions space. Broadly they are: acquiring large technology companies as initial customers, dealing with the misalignment of our economic systems and Earth's ecological systems, and needing to plan within a context where Earth's climate has already changed. Understanding these themes as they relate to mass timber should help guide those involved with the material as it begins to attract even more attention.
It's become abundantly clear in the last few years that if you’re working on a climate technology solution, big tech companies are your best bet for a first or significant customer. While we should always be suspicious of greenwashing, these companies are at least putting up money. The most substantive trend thus far has been the growth in renewable power purchase agreements made by the likes of Apple and Google. More recently the trend has been purchasing carbon accounting software and funding carbon removal projects. Tech companies generally have healthy margins and leadership that seemingly does want to decarbonize. A perfect combination for an initial customer. And even in the worst case of greenwashing, these companies represent a means for paying the bills long enough to work a solution down its cost curve.
Mass timber buildings are another area where this is happening and even large non-tech companies are involved. Microsoft, Walmart, Toyota, and Google all have significant mass timber plans. In most real estate contexts cost drives everything and lifecycle assessments are definitively just "nice-to-haves". With these large corporations however, the climate story mass timber provides is compelling and the capital to spend is available. It’s even more appealing because unlike a far away solar farm or carbon removal project, everyone can see and touch a mass timber building. The long-term promise of mass timber outside of replacing steel and concrete is that can also lower construction time and therefore costs. This has yet to be repeatedly proven however. Using these companies to find that proof is critical to future growth. To put it in a well known framework, it’s the Tesla method. Gain experience and reduce costs with those who can afford to pay a premium, and then take those improvements and move downmarket. In an ideal world this kind of “trickle down” strategy would be unnecessary but such is not the case and leads to the next theme.
Climate change can very easily be characterized as the misalignment between an economic system that is built around never-ending growth and a natural world where there’s no process that has never-ending growth...heat death and all. I’ll continue to push my recommendation to read Kate Raworth’s Doughnut Economics if you haven’t yet. Every climate solution in one way or another has to contend with how to succeed in an economic environment that pushes for infinite growth while relying on a natural environment that is very finite. Even the fossil fuel industry has had to placate fears of “peak oil” for decades. The debate between decoupling and degrowth is too nuanced to cover here but the point remains that we’re pushing up against the barriers of Earth’s natural systems while still locked into the economic system that’s got us to this point.
As it relates to mass timber, we’re getting close to having the technology to count every tree on Earth. The finiteness of trees and their place in our hearts makes the misalignment of economic and natural systems especially pronounced when it comes to mass timber. The good news is that it’s not an immediate problem in North America. Forests have been growing in wood mass for the past 50 years despite all of our residential construction. Mass timber itself isn’t even tracked by the USDA lumber consumption and production reports yet. The bad news is that there very much is some optimal quota of harvest that balances the ability of forests to serve as a carbon sink and the capability of mass timber to sequester carbon and offset steel and concrete usage. What happens when we hit that quota and demand continues to increase or investors push for more growth from the industry? Balancing the needs of our economic system against the limits of our natural systems must be confronted head on. Proactively supporting smarter regulation, afforestation efforts, and R&D into lab grown wood seem like the best answers at this time. It’s not an easy problem but given the visibility of trees and mass timber buildings, tackling this issue must be top of mind moving forwards.
The final theme is adjusting to a world that has already shifted under our feet. Despite the clamor of environmentalists that climate change has arrived, most industries have yet to really internalize that even the world of ten years ago is not relevant to what is happening today. Hurricanes are more intense, heat waves are increasing in frequency, and wildfires are burning more land. Living in a world where the climate has changed means taking actions that incorporate what’s different. A good example of this is Climate AI, a new way of making weather forecasts for farming in a world where just using the historical average no longer works. A not so good example is the recent Texas power catastrophe. Natural gas power generators did not winterize their systems because they wanted to save money and didn’t account for the fact that such cold snaps are now very much a possibility in a world where the climate has changed. Success in the future will be tied to our ability to adapt to higher variance in the environment.
In the world of mass timber, this means contending with the growing threat of wildfires in places like California and the Pacific Northwest. The ever present danger of wildfires will mean changing the way we think about how to use our forest resources. Fire-risk modeling is a growing field and with it comes the possibility of predicting where and when fires may occur with higher degrees of certainty. It’s not inconceivable that a Minority Report style preemptive harvesting practice is what’s required in the future. Forest management today involves thinning smaller diameter trees in the hopes of preventing wildfires from spreading. But if we now live in a world where there are more fires regardless of thinning and we know with high confidence which areas are most at risk, it might make sense to harvest trees in those areas in advance. Consider that in 2020, over 4 million acres of land burned in California alone. All the carbon in those trees that burned is now in the atmosphere, but if those trees were put into mass timber construction that carbon would have been sequestered into buildings instead. This method of thinking is lacking today because we’ve yet to fully readjust to our changed world. Wildfires are a balanced part of a forest ecosystem, but they might not be in our future where balance no longer exists. This is another situation where mass timber provides a clear cut example of how new adaptions will be required to adjust to our changed world.
The trajectory of mass timber in North America is already one of rapid expansion for the next few years. But beyond that the degree to which it becomes a standard in the construction industry depends on how the themes discussed affect the companies involved. Architecture and construction firms should seek to work with more of those large corporations who can afford to fund those initial projects. The entire supply chain should keep the tension between economic growth and environmental sustainability in mind and take steps to bring alignment at every opportunity. And forest owners and panel manufacturers should start to adapt their strategy and tooling for a world that burns more. Wood as a building material has its roots in the farthest reaches of our past. Mass timber is quickly growing into the future of our lives. How far it extends is all that’s left to be seen.