Even the most sustainable new architecture has a carbon footprint from construction, since raw materials have to come from somewhere and construction takes energy. But what if the process of building actually helped suck carbon out of the atmosphere?
That might be possible through a unique process of “growing” buildings using underwater microorganisms, say U.K.-based architects at a firm called Exploration. The idea is that the organisms use carbon to grow and can actually be trained to grow in the shape of a building–creating a new material called BioRock.
“You make a steel frame, put it in seawater, and pass a very small current through it–not enough to be harmful to wildlife–and you get electro-deposition of minerals,” explains Michael Pawlyn, director of Exploration. “If you grow it at a slow rate, it can match or even exceed the strength of reinforced concrete. Our intention is to make a whole building out of this.”
After some further testing and prototyping, Exploration plans to start by building a small outdoor theater from the material. Eventually, after the concept is proven, they hope to use the technology at a larger scale.
The starting point for the project was the firm’s deep expertise in taking inspiration from the natural world. “The Biorock Pavilion is, in a way, about trying to push biomimicry to the absolute limits,” says Pawlyn. “In this case we’re asking a really demanding question: How would biology, through the long process of evolution, solve the problem of climate change?”
One clue, Pawlyn says, comes from ice core data, which show how temperature and carbon dioxide levels have changed over hundreds of thousands of years. Usually, scientists use the data to document the crazy exponential growth of CO2 in the atmosphere in modern times. But the data also show that carbon and temperature have gone up and down at lower rates, again and again, over time, and Pawlyn wondered what made carbon levels fall in the past.
Some scientists say that the rise of large numbers of marine organisms called coccoliths were once responsible for a drop in CO2 in the atmosphere–the coccoliths use atmospheric carbon to grow their own skeletons, and when they die, they fall to the ocean floor and eventually become rock, taking the carbon with them. These are the organisms that Pawlyn hopes to put to work in his new buildings, beginning with his shell-shaped pavilion.
“We’re convinced that making things from atmospheric carbon will become one of the tools for reducing CO2 levels in the atmosphere,” he says.