Posted on March 21, 2023 by Charles DiLeva
Since retiring from environmental leadership positions at the World Bank, I have taken on teaching assignments including a course entitled “Circular Economy in the Construction Sector”. The students taking this course are preparing a report on the topic for the United Nations Environment Program focusing on North America and the legal and policy landscape, particularly on “Sand and Sustainability”. See https://www.unep.org/resources/report/sand-and-sustainability-10-strategic-recommendations-avert-crisis.
Why sand, you ask? Sand (i.e., sand, gravel, and aggregates) is the most used solid material in the world, averaging 50 billion tons per year. After water, it is the most extracted natural resource. Yet, unlike water, in most parts of the world sand extraction is poorly regulated, and/or subject to a confusing array of overlapping regulatory authorities. Moreover, unlike other extracted resources, such as timber and high-value minerals, there is little to no supply chain oversight. Even voluntary standards, such as those for mineral ores, have paid little focus to sand used for construction purposes.
Nevertheless, based on GIS and other data and an array of monitoring practices, the environmental community is increasingly aware of the environmental damage being caused by sand extraction. In many places, sand is being used faster than it can be replenished, and is often extracted causing severe damage to biodiversity, fishing grounds, coastal and beach stability, and an erosion of beaches and riverbeds. The growth of this problem is exacerbated by several factors including climate change and associated coastal erosion and sea-level rise; demand for new building and road construction linked to post-COVID recession and population growth; and for ore-sand that provides critical materials for industrial use and sand for fracking, including the sands of the Great Lakes region. See, e.g., https://greatlakesecho.org/2018/03/22/oil-boom-boosts-sand-mining-along-great-lakes.
The problem is also compounded by inadequate regulation to address the growing volume of construction and demolition waste which often dominates increasingly scarce landfills, and can interfere with carbon-capture methane recovery. Still too inexpensive disposal options discourage reuse of otherwise reusable concrete and other sand-bearing materials, including glass. Yet few communities seem to impose taxes or create other incentives that would facilitate recycling. If such incentives were in place, there would also be less demand for continued extraction. Fortunately, some examples are emerging and the course research is identifying initiatives in North America that may lead to more efficient use of resources, and less carbon footprint. For example, the American Wood Council points out jurisdictions providing policy measures and incentives to use laminated wood in place of concrete and steel. See https://www.woodinstitute.org/login/index.php. Not only does such material avoid the need for sand extracted for concrete, it also provides the benefit of storing carbon for the product’s life.
The Green Building Council https://www.usgbc.org/leed/v41, and CALgreen, https://aiacalifornia.org/calgreen-checklists/ are setting policies, standards, and checklists that help provide for Net Zero building and demonstrate how the building design industry, along with the American Institute for Architects is moving in the green building direction.
My students’ report on moving toward a circular economy in the construction sector will be out later this spring.