The construction industry is a major contributor to global carbon emissions. The production of traditional building materials like concrete, steel, and aluminum is highly energy intensive and generates massive amounts of CO2. Being mindful of the carbon footprint of the materials we can significantly reduce the climate impact of all projects.
Major Sources of Carbon Emissions
Cement production alone accounts for around 8% of global CO2 emissions. The calcination process to make cement releases CO2, as does the burning of fossil fuels to heat the kiln. Concrete's other ingredients like sand and gravel also have emissions from mining and transportation. Steel production generates 7-9% of the world's carbon emissions. The use of coking coal to reduce iron ore in blast furnaces releases significant CO2. The smelting process to make aluminum is highly electricity-intensive, leading to indirect greenhouse gas emissions.
Greener Material Innovations
Fortunately, some leading manufacturers are innovating to reduce the carbon footprint of their products:
Companies like Rockwool use recycled inputs like slag and stone wool to reduce emissions from mineral wool insulation. Wienerberger's Porotherm clay blocks have up to 50% lower embodied carbon than concrete blocks. Reynaers aluminum systems are Cradle to Cradle certified for their use of renewable energy and recycled content. Saint Gobain produces CO2-reduced plasterboard using flue gas desulphurization gypsum. Sika has developed low-carbon concretes including CO2-cured solidia concrete.
Sustainable Design Strategies
We must take responsibility for emissions starting from the concept phase. Some strategies include: