I passed late afternoon trucks lined up by the roadside - diesels rumbling, slowly turning loads of concrete waiting to be pumped to the next floor to set overnight. They build here as fast as the concrete allows, a new floor every week. Walking through the heat from the trucks set me thinking about whether energy costs are factored into construction (and, for that matter, demolition), or whether they are just a cost to society. Viable condominiums are sold en bloc and demolished top-down only for new construction to arise the moment the site is cleared. Ten years here is old, twenty is ancient. Build, destroy, consume — it all seems hard and alien. Concrete production is energy intensive too: calcining limestone releases carbon dioxide, quite apart from that released by the fuel for the kilns. Then we air-condition the resulting stone boxes, and so it goes on.
Wikipedia, perhaps not always the most reliable of sources, says "as of 2006, about 7.5 cubic kilometres of concrete are made each year—more than one cubic metre for every person on Earth" and that "the cement industry is one of two primary producers of carbon dioxide (CO2), creating up to 5 percent of worldwide emissions of this gas. The embodied carbon dioxide (ECO2) of a tonne of concrete varies with mix design and is in the range of: 75–176 kg CO2/tonne". (ref.)
Walking through the shimmering heat, there was no arguing with this. It may already be too late.
