As Portland Continues to Grow, Are We Prepared to Address the Resulting Increase in Emissions?

By Greg Hibbard, Energy Law Fellow

Portland Bureau of Transportation

On June 30th, the popular food carts in the Alder Street pod in downtown Portland were forced to relocate so construction can begin on a new 35-story tower at 900 S.W. Washington St. The building will host a Ritz-Carlton hotel—Portland’s first five-star hotel—in addition to condos and office space. The Ritz-Carlton will include over 350 rooms and condos, eight penthouses, and a swimming pool on the 19th floor. At least a portion of what will become the fifth tallest building in Portland will be constructed using concrete panels. While the Ritz will represent a level of luxury not previously constructed in Portland, the new hotel represents the latest addition to a growing metropolitan area that has seen over 2,000 hotel rooms added downtown in the last 10 years. Because the hotel industry only represents a fraction of the growing city, Portland’s rapid rate of development begs the question of how much environmental harm is being accepted in the name of expansion and luxury.

A recent E&E News story explored the massive carbon footprint of modern structures. The story stated that 11% of global carbon emissions can be attributed to construction. The main emissions culprits, at least in terms of modern structures, are steel and concrete. The manufacturing process for steel involves heating iron ore in a blast furnace, which produces the byproducts of iron and carbon dioxide. According to E&E News, the World Steel Association estimates that producing one ton of steel releases 1.83 tons of carbon dioxide into the atmosphere. That quantity of emissions is equivalent to the emissions that result from a roundtrip drive from New York to Salt Lake City. Similarly, concrete production also generates significant carbon emissions. Producing cement is an interim step of concrete production. Cement is produced by baking limestone, which produces the undesired byproduct of carbon dioxide. One ton of cement results in roughly half a ton of carbon dioxide. According to the International Energy Agency, cement accounts for nearly 7% of global carbon emissions.

E&E News estimates that local governments and mayors have the ability to significantly reduce lifetime emissions for buildings—by up to 44%— by improving energy efficiency and incentivizing the use of greener building materials. The environmental costs of improved energy efficiency warrant a separate discussion. However, energy efficiency is another example of how convoluted emission solutions can be. For example, using triple-glazed windows may appreciably reduce heat loss and conserve energy but they are also more carbon intensive to produce and ship.

With respect to building materials, Portland has already taken strides to ensure that further construction is done in an environmentally friendly manner. For example, through its participation in C40 Cities, Portland joined cities from all around the globe to commit to obtaining the goals of the Paris Agreement. Through its C40 commitment, Portland has pledged to ensure that all new buildings are net-zero carbon by 2030. Portland Mayor Ted Wheeler has shown a personal interest in the C40 initiative, stating that “[e]nsuring Portland’s old and new buildings achieve net zero carbon use is an essential challenge that I am ready to take on.” Unfortunately, Portland’s efforts are inherently limited by state building codes. Portland is preempted from adopting its own building code requirements and must look to economic incentives or other strategies to accomplish many of the goals that Mayor Wheeler wishes to achieve.  

Regardless of what form the city’s policies ultimately take, increasing the use of low-carbon building materials presents an opportunity for Portland to further its goals of constructing net-zero carbon buildings. While buildings such as the future Ritz-Carlton will continue to require concrete and steel in the near future, it is time for Portland to begin looking for greener building options. Although there are currently identified options or alternatives to concrete and steel, such actions also present drawbacks. For example, steel can be produced in a less carbon-intensive manner if hydrogen is used to purify the iron ore rather than coal, but it may take another decade until such technology is readily available on a mass scale. Another potential option is to use different building materials, such as wood, as a substitute for steel or concrete. Even assuming wood is mechanically comparable to steel or concrete, using wood as a primary building material may bring about more environmental questions than answers. Among other issues, increased timber production threatens habitat for certain species and the ability of forests to sequester carbon.

At this point in time, there are no easy answers to the environmental issues posed by steel and concrete building materials. In the very least, we must consider the appropriate questions to address the carbon intensity of the most commonly used building materials. Can we clean up the production processes for steel and concrete? Are there economically and mechanically viable alternatives to building with steel and concrete? And if there are viable alternatives, such as wood, are their potential environmental impacts worth the switch? The forthcoming Ritz-Carlton Hotel in Portland is a sign of continued prosperity in the city. We must be prepared to account for the potential emissions cost of that prosperity.