When it comes to CO₂ emissions, it’s easy to put the blame solely on the burning of fossil fuels such as coal, oil and natural gas. However, the building and construction industry does have some share in this issue. It’s time the industry takes a look at its own CO₂ contributions and take steps to cut emissions and embodied carbon.

According to the U.S. Energy Information Administration, the building sector was responsible for 44 percent of U.S. CO₂ emissions in 2010, through greenfield development, cement production and the burning of fossil fuels—that’s more than the CO₂ emissions produced by transportation (34 percent) and industrial operations (21 percent).

The building and construction industry is at a crossroads. It can continue to be part of the problem or evolve and do its part to help mitigate the effects of global warming. According to Architecture 2030, a non-profit that was established to address the climate change crisis, an area 3.5 times the entire built environment of the United States will be redesigned and rebuilt globally over the next 20 years. This is the building industry’s opportunity to shift from its traditional approach and use tactics to dramatically reduce its CO₂ footprint.

Some industry changes to adopt include:

1. Choosing materials with lower embodied carbon and sourcing materials from suppliers that are transparent in regard to the makeup of their products. 
2. Better design. Architecture 2030’s “The 2030 Challenge” urges the global architecture and building communities to meet several targets, including a fossil fuel, GHG-emitting, energy-consumption performance standard of 70 percent below the local average for that building type. That 70 percent increases to 80 percent by the year 2020, 90 percent by 2025 and becomes carbon-neutral in 2030.
3. Using waste and recycled materials.
4. Extending the building’s life; a longer life span delays and reduces the embodied carbon associated with deconstruction, demolition, waste processing and rebuilding.
5. Increased use of prefabricated elements and offsite manufacturing. 

As the industry creates more energy-efficient buildings, it should also look to power them from renewable sources. The first priority should be to incorporate on-site power generation from renewable sources, including solar, wind, geothermal and hydropower, and then procure renewable energy from fully certified sources when it’s unable to be produced on site.

While there has been a concerted effort to reduce operational carbon emissions, that isn’t the case with embodied carbon. Reducing embodied carbon is just as important as reducing operational carbon, as the amount used to create a building can be as high as 65 percent. According to CarbonBrief, around 22 percent of global CO₂ emissions come from the production of goods that are consumed in another country.

While the United States and many European countries have reduced their carbon emissions, those reductions are offset by increasing imports that contain high levels of embodied carbon. The United States is the world’s largest CO₂ importer, and China is by far the largest CO₂ exporter, exporting five times as much as the next country (Russia). Since 1990, the United States has reduced its carbon emissions by 9 percent; but according to CarbonBrief, that becomes a 17 percent increase when you factor in trade.

Calculating the embodied carbon from cradle to grave for a building is no simple task. Fortunately, there are a number of resources, including the Inventory of Carbon and Energy (ICE) database that details the energy consumed to create more than 200 building materials.

The state of California is setting an example with its Buy Clean California Act, which requires that the state set a maximum “acceptable lifecycle global warming potential” for different building materials, and specifying that only materials with embodied emissions below that level can be purchased by the state. And since the state government is the largest purchaser of steel and concrete in California, proponents of the measure hope that it will help promote lower-carbon production practices.

Climate change is a fact and its impacts can’t be ignored. The building and construction industry has the opportunity to evolve and play a significant role in whether the impact of climate change in the coming years will be manageable or disastrous.