rjzimmerman:

---

Excerpts from a Guardian article entitled, “Concrete: the most destructive material on Earth:”

In the time it takes you to read this sentence, the global building industry will have poured more than 19,000 bathtubs of concrete. By the time you are halfway through this article, the volume would fill the Albert Hall and spill out into Hyde Park. In a day it would be almost the size of China’s Three Gorges Dam. In a single year, there is enough to patio over every hill, dale, nook and cranny in England.

After water, concrete is the most widely used substance on Earth. If the cement industry were a country, it would be the third largest carbon dioxide emitter in the world with up to 2.8bn tonnes, surpassed only by China and the US.

It also magnifies the extreme weather it shelters us from. Taking in all stages of production, concrete is said to be responsible for 4-8% of the world’s CO2. Among materials, only coal, oil and gas are a greater source of greenhouse gases. Half of concrete’s CO2 emissions are created during the manufacture of clinker, the most-energy intensive part of the cement-making process.

But other environmental impacts are far less well understood. Concrete is a thirsty behemoth, sucking up almost a 10th of the world’s industrial water use. This often strains supplies for drinking and irrigation, because 75% of this consumption is in drought and water-stressed regions. In cities, concrete also adds to the heat-island effect by absorbing the warmth of the sun and trapping gases from car exhausts and air-conditioner units – though it is, at least, better than darker asphalt.

The heat and chemical processes involved in making cement (a key component of concrete) mean that each tonne made releases a tonne of CO2. Photograph: Zoonar GmbH/Alamy Stock Photo/Alamy Stock Photo

Excerpts from another Guardian article, entitled, “Concrete is tipping us into climate catastrophe. It’s payback time:”

Cement, the key component of concrete and one of the most widely used manmade materials, is now the cornerstone of global construction. It has shaped the modern environment, but its production has a massive footprint that neither the industry nor governments have been willing to address.

Because of the heat needed to decompose rock and the natural chemical processes involved in making cement, every tonne made releases one tonne of C02, the main greenhouse warming gas.

So great is its carbon footprint that unless it is transformed and made to adopt cleaner practices, the industry could, on its own, jeopardise the whole 2015 Paris agreement which aims to hold worldwide temperatures to a 2C increase.

While some of the biggest cement companies have reduced the carbon intensity of their products by investing in more fuel-efficient kilns, most improvements gained have been overshadowed by the massive increase in global cement and concrete production. Population increases, the urban explosion in Asia and Africa, the need to build dams, roads and houses, as well as increases in personal wealth have stoked demand.

Industry leaders are now embarrassed, aware that they are in danger of being financially penalised and tarred as climate laggards who refuse to change in the face of the climate emergency. They well know that not only is it quite possible to build most structures safely without cement, but their own research has shown that green, cement-like products using recycled byproducts which are just as strong can be made from other industries, such as steel slag, fly ash from coal-fired facilities or some types of clay. Instead they trust that nascent technologies like carbon capture and storage which could allow emissions to be buried will come on stream, and that more efficient plant will reduce cement emissions by as much as 20-25%.