Baking mud and clay to make bricks releases 800 million tons of greenhouse gasses each year worldwide. That’s more than all the world’s air traffic combined. And then there’s the energy it takes to bake limestone and gypsum into cement and plaster and other building materials. The energy it takes to build modern structures is immense and growing. A new development in brick-making may change all that, though, offering us a chance to accomplish all of this with a tiny fraction of the energy and work.

Working at a university in the United Arab Emeriates, American scientist Ginger Krieg Dosier has designed a process for mass-producing bricks made largely from sand. By injecting a bacterial culture and growth medium, she’s been able to harden the sand to match limestone or even marble. This happens through microbe-induced calcite precipitation (MICP), a process where the microbes lay down minerals through the structure, which then dry into cement-like hardness.

So far this process has worked only on a small leg0-like scale and is sill rather slow. There’s no telling how long it may be before you or I get to play with something like this. Nevertheless, if adopted worldwide, it would change the way we build things. A microbial culture which could replace cement would be in many ways the holy grail of sustainable building. Could this work with larger blocks? Could we pre-form walls? WOuld it work in earthbag-style designs? There are too many exciting possibilities to name, so keep your eyes out.