Letter to the editor: No carbon now!

Photo by Unsplash

Thank you for running Anthony Pak’s article on embodied carbon (CA, July 2019). As an industry, we’re catching on to the idea that embodied carbon is significant, especially as we develop more and more energy-efficient buildings.

The timeline of the necessary change is breathtaking—and also inspirational. Four months. That’s all we have to transform as an industry. 15 months if we’re being generous. And transform we must! There is no option—or planet—B. The act of city building would not be possible without the literal city builders, i.e., the entire construction industry—building owners and managers, architects and engineers, general contractors and tradespeople, and material manufacturers and suppliers.

All of us as “city builders” have an important role to play. And when it comes to the climate crisis, that role must change. We must cut carbon out of construction—now!

Massive amounts of carbon dioxide are emitted into the atmosphere during the construction of a building (embodied carbon) and during the lifetime operation of a building (operational carbon). These massive carbon emissions must stop, and we as an industry must change.

According to a 2017 report by the World Green Building Council (WorldGBC), the global construction industry, which is responsible for 30 percent of global greenhouse gas emissions (roughly equivalent to those of China) must operate at “net zero carbon” by 2050 if global warming is to remain under two degrees Celsius—the limit enshrined in the Paris Agreement.

Not only that, but “Every building on the planet must be ‘net zero carbon’ by 2050 to keep global warming below 2°C” (emphasis mine). This means every building… whether new or existing. Further, it is likely that, in 2017, WorldGBC was only considering operational carbon, and not embodied carbon.

How can we transform both the operation of existing buildings, and the construction of new buildings, to emit near-zero carbon?

There is nothing that we can do to reduce the embodied carbon in existing buildings, as it has already been emitted during construction. But we can respect that that carbon has been emitted, and maintain the building’s existing structure by retaining it as-is or transforming it through adaptive reuse. The alternative is to demolish that structure and send its component parts to landfill, only to emit more carbon during the construction of a replacement building.

Further, we can retrofit an existing building so that it is optimally energy efficient, thus reducing its operational carbon going forward.

To reduce operational carbon, in Ontario we could electrify everything—both new and existing buildings. We have one of the most carbon-clean electrical grids on the planet.

Sustainable. Architecture for a Healthy Planet has just completed an air-tight and well-insulated home that requires 87 percent less energy to heat, cool and operate than a conventional home. Our Six Points home is all-electric, including an all-electric car.

Photo Courtesy of Sustainable.

Embodied carbon is becoming significant for the way we think about sustainable buildings, too. Regarding the term “embodied carbon,” I appreciate Lloyd Alter’s blog post in Treehugger, where he says that the term hides the urgent need to deal with the carbon that is emitted as a result of the construction process. Instead, he suggests we all use the term “upfront carbon emissions”—”because that’s what they are.”

Pak’s article reveals that: “The importance of embodied carbon becomes even more evident when you consider that, according to the IPCC, to limit global warming to 1.5°C, carbon emissions would need to peak next year in 2020 and then go to net zero globally by 2050. Given that embodied carbon will make up almost half of total new construction emissions between now and 2050, we cannot ignore embodied carbon if we want to have any chance of hitting our climate targets.”

2020 is three months from now—three months to peak our global carbon emissions! (15 months if we’re being generous and giving ourselves to the end of next year.)

What we cannot ignore any longer is that the manufacturing processes for concrete, steel and asphalt—the assumed inevitable foundations of our construction industry—are huge emitters of carbon.

Writing in The Guardian, Jonathan Watts calls concrete, “the most destructive material on earth.” What to use instead? A forest—the “wood factory” if you will—is a carbon-sink, drawing down carbon from the atmosphere, and moving us in the right direction with our carbon emissions. According to Project Drawdown, which cites a 2014 study, “Building with wood could reduce annual global emissions of carbon dioxide by 14 to 31 percent.”

But getting the designers and builders in the construction industry to convince the concrete, steel and asphalt industries to give up their predominant position will be on par with getting the petroleum industry to give up theirs. They are all big, and powerful, and not terribly willing to change.

But there is hope. Skanska, the world’s largest construction firm, has committed to a net-zero carbon operation by 2045. A promotional piece on their initiative encourages us to: “Think of a world where fantastic buildings… are created… giving [people] great places to live and work in, and where the CO2 impact during construction is… well, there isn’t one. That would be a future we could really look forward to.

Choosing to bring the embodied and operational carbon of buildings to near zero is hard, and it is also necessary for our survival. We must embark on a program of city rebuilding.

It is time for all of us to do something. And to do it now.

Medium writer Marta Brzosko says it best: “We are all on this sinking ship together—and we are afraid. That’s only natural. But this is precisely why it’s the time to find courage. The courage for acting and speaking about the climate crisis, no matter how uncomfortable it may be. Because, as Greta Thunberg says, our house is on fire. And to ignore the fact that your own house is burning is just ridiculous.”

Paul Dowsett, OAA, FRAIC, LEED AP; Principal Architect, Sustainable. Architecture for a Healthy Planet.