As the climate crisis intensifies, governments, manufacturers, retailers, and consumers are increasingly expanding their conception of sustainability to include embedded emissions (also referred to as embodied emissions, embodied energy, embedded carbon, etc.). There is no standard definition of embedded emissions. In short though, a product’s embedded emissions are the sum of greenhouse gas emissions required to bring the product to market. This includes emissions generated through raw material extraction/farming, processing of materials, as well as the manufacturing and transportation of the final product. Some definitions also include emissions associated with the use and eventual disposal of a product, very similar to the product lifecycle approach.
Building materials, especially cement which was responsible for 8% of global carbon emissions in 2015)[i], have a significant climate impact. Consequently, the construction and architecture industries are the farthest along in considering and measuring their embedded emissions. In construction, a distinction is made between embedded carbon and operational carbon. Embedded carbon is, as it were, baked into a building, while operational carbon (associated with heating, cooling, plumbing, etc.) can be reduced after the initial build through efficiency upgrades. Green building standards like LEED take embedded emissions into account and the “Buy Clean California Act,” passed in 2017, limits the “acceptable lifecycle global warming potential” of building materials that can be purchased by the state.[ii]
The concept of embedded emissions is also used to establish individual countries’ carbon budgets in international climate agreements. Countries with service-based economies (often running trade deficits) rely on higher emissions in manufacturing-intensive economies for the products that they import. In considering embedded emissions of imported goods, climate agreements assign some of the responsibility for these emissions to the high consumption, service-based economies that demand them.
There are a number of approaches to reducing the embedded emissions in the products we consume. Retailers like Ikea and Patagonia are taking the extended producer responsibility strategy to a new level; they have started buying back products from customers, which they then repair and remarket. In construction and other industries, embedded emissions are being reduced through the use of alternative materials (FSC certified wood in lieu of concrete, for instance) and by engaging with the circular economy to reduce the embedded emissions of materials like concrete.
Indeed, the concrete industry has long been a driver of the circular economy. Utilization of supplementary cementitious materials like fly ash and ground granulated blast furnace slag, (by-products of the coal and iron industries, respectively) in the production of cement and concrete is common practice, and other waste streams are diverted from incineration/treatment/etc. to be used as alternative fuels for cement kilns.
WTS, Inc. plays a key role here, having diverted 328.03 million lbs. of material for use in the cement industry between 2010-2019. WTS is committed to powering the circular economy. As part of that commitment we are introducing the WTS Materials Hub, a listing of by-products and co-products available for reuse. In diverting materials from traditional disposal, we strive to not only avoid landfill and incineration emissions, but also to logistically connect producers, distributors and end-users of various categories of reusable materials to help manufacturers reduce the embedded emissions in their supply chains.