GatesNotes – October 28, 2019
Besides the traffic and the weather, we Seattleites love to talk about all the construction going on in our city. The downtown skyline is full of cranes, and it seems like the building never stops. By the end of the year, 39 new projects will have been completed in downtown Seattle alone, and there are plans for more than 100 others to be finished in the next two years.
Seattle is hardly alone. As the global population rises, urban areas around the world are booming, and that means more and more buildings are going up. By one estimate, the world will add 2 trillion square feet of buildings by 2060—the equivalent of putting up another New York City every month for the next 40 years.
There’s good and bad news in that statistic. The good news is that living in the city generally equates to a higher quality of life—you have access to better schools, health care, and job opportunities. The bad news is that the buildings themselves are a big contributor to climate change, and one of the five areas where we need to drive a lot of innovation if we’re going to avoid a climate disaster.
There are two ways in which buildings are responsible for greenhouse gases. The first is the construction phase: Buildings are made of concrete and steel, both of which produce a lot of emissions when they’re being made. In fact, these two materials account for around 10 percent of the world’s annual greenhouse gases. And right now, we don’t have practical ways to make either one without releasing carbon dioxide.
This summer I wrote about a company called Boston Metal (which I’ve helped fund through Breakthrough Energy Ventures) that’s trying to change that, by developing a way to make zero-carbon steel using electricity instead of coal. The video below features a company called CarbonCure, which BEV has also invested in. CarbonCure has a clever approach to injecting carbon dioxide into concrete.
But what if labels didn’t just reveal how energy-efficient something is, but how many greenhouse gas emissions it’s responsible for? That’s the idea behind the Embodied Carbon Calculator in Construction, which tells you how much carbon was used to produce steel, cement, and other materials made by companies that volunteer the information. This data will be even more important in the years ahead; right now, 80 to 90 percent of emissions come from running the building over its lifetime, but as we use cleaner sources of electricity and make buildings more efficient, the emissions from construction materials will represent a larger share of the total.
Another step that will help is for companies and governments to commit to buying lower carbon materials for their building projects. California, for example, has a new “Buy Clean” policy, and Microsoft has a goal of reducing embedded carbon by 15 to 30 percent as it rebuilds part of its headquarters in Redmond, WA.
Finally, we can strengthen our building codes to ensure that buildings are designed to be not only energy efficient, but built with low-carbon materials. Unfortunately, some rules actually make it hard to use these materials. For example, if you want to put concrete in a building, the building code might define the precise chemical composition of the cement you can use in it. But that standard may rule out low-emissions cement, even if it performs just as well as the conventional kind.Obviously, no one wants to see buildings and bridges collapsing because we relaxed our codes too much. But we can make sure the standards reflect the latest advances in technology, and the urgency of getting to zero emissions.