10 Emerging Technology Solutions for Planetary Health 2025

Miriam L Diamond Professor, Earth Sciences and School of the Environment, University of Toronto Emircan Ozcelikci Civil Engineering Department, Hacettepe University Mustafa Şahmaran Professor of Civil Engineering, Hacettepe University Concrete is the most widely used construction material on Earth. Production of its key binding ingredient, Portland cement, contributes approximately 8% of global CO2 emissions and drives unsustainable demand for sand, stripping riverbeds and coastlines and damaging ecosystems.41,42 Novel cement-free green concrete technologies offer an alternative by eliminating Portland cement altogether and instead using binders derived from industrial byproducts or construction and demolition waste (CDW).43,44 Some of these technologies also enable CO2 mineralization during curing, where CO2 is actively introduced and sequestered into the concrete matrix. This process not only eliminates emissions from traditional cement production but also creates a permanent storage route for captured CO2.45 Together, these advances cut demand for extracted raw materials and ease pressure on planetary boundaries related to climate change, land-system change, biogeochemical flows and novel entities. Geopolymer binders, a key example of cement-free systems, are produced by chemically activating aluminosilicate-rich materials such as fly ash, blast furnace slag or milled CDW. Use of these waste materials displaces the use of virgin limestone, sand and gravel, thereby avoiding the energy-intensive, high-temperature, high-emission reactions required to make Portland cement. Geopolymers divert waste from landfills and circumvent resource extraction, which supports circular, lower-impact construction practices. When coupled with CO2- curing techniques, the result is a durable, lower- carbon concrete that stores captured CO2 while meeting performance needs. Sublime Systems uses electricity and non-carbonate materials to produce low-emissions cement, reducing CO2 emissions by 90% compared to ordinary portland cement, without compromising strength.46 Experimental methods have mineralized up to 45% of the injected CO2 – permanently storing it without compromising structural performance.47 In one demonstration, researchers constructed a full-scale, one-story home using prefabricated components made entirely from CDW and CO2-enhanced materials.48 Structural and life cycle assessments indicated durability, high reuse potential and significantly reduced emissions. These approaches have gained regulatory approval in multiple countries, including Germany, Canada and the US.49 As continued innovation brings green concrete into mainstream building practices, it is reducing environmental impacts, generating new jobs in low-carbon construction and highlighting persistent barriers to equitable adoption. By reducing emissions and storing carbon, green curing reduces the pressure on the climate change boundary. Geopolymers ease pressure on land systems and limit novel entities. When paired with recycled aggregates, both approaches reduce demand for raw materials and thus help address land-system change and biogeochemical flows. Industry-wide adoption could create new jobs in demolition recovery, CO2 utilization, recycled binder production and circular construction. Although these technologies can enable distributed, modular concrete production and reduce reliance on centralized cement infrastructure, equity challenges remain – particularly in regions with limited access to technical expertise, financing or procurement flexibility.50 Procurement standards, workforce development and investment in regional recycling and manufacturing capacity could help ensure green concrete technologies deliver environmental and economic benefits where they are most needed – enabling essential infrastructure to be built faster, cleaner and with far less environmental impact. Green concrete can not only eliminate emissions from traditional cement production but also create a permanent storage route for captured CO2. 10 Emerging Technology Solutions for Planetary Health 20