This week, LAM is joining more than 250 media outlets for Covering Climate Now, flooding the zone, as it were, with climate coverage in the run-up to the United Nations Climate Action Summit on September 23. Landscape and landscape architecture are deeply implicated in the future of climate progress, or a lack of it. Over the past decade, LAM has dug into climate issues of landscape in numerous dimensions, mapping the big resource picture as well as local attempts to fend off increasingly apparent hazards of global warming—from the procurement of materials to the integrity of the food supply chain. Each day this week we’ll bring you excellent stories from recent years that follow landscape architects acting and thinking about climate change and the landscape.
FROM THE JULY 2017 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE.
Concrete in the 21st century promises to be a more sustainable material, and given the nine billion metric tons used globally each year, it must be. Portland cement, the binding agent in ordinary concrete, has a very high carbon footprint, resulting in just under one ton of carbon dioxide (CO2) released for every ton of cement produced. With 4.2 billion metric tons of the binder used each year worldwide, cement production is responsible for nearly 8 percent of total global carbon emissions. The high lime content of ordinary portland cement contributes about two-thirds of cement’s CO2 impact through the process of limestone calcination. The other one-third of CO2 released is from combustion of fossil fuels.
Technologies to improve the carbon footprint of concrete are currently in the early stages of development, but some, including carbon sequestration in concrete and substantial reductions of cement using energetically modified cement, are now commercially available. Concrete surface products for paving and walls to scrub air pollution, as well as new self-healing concrete products, are also worth investigating. We have heard about some of these innovations for a decade or more in the research community, but many are finally being brought to market—some more quickly than others. Europe is ahead of the United States in the adoption of these technologies, largely because of more rigorous clean air and carbon reduction initiatives.