Desertification, the degradation of land in arid areas, is a growing problem due to deforestation, fires, and climate change. Magnus Larsson, a student at London’s Architectural Association has a drastic solution–a 6,000 km long wall of artificially solidified sandstone spanning the Sahara Desert from east to west. Dunes along Larsson’s sandstone wall will act as a combination of refugee housing and a block against the desert.

The project, which won first prize last fall in the Holcim Foundation’s Awards for Sustainable Construction, proposes using bacillus pasteurii–a microorganism found in wetlands and marshes–to solidify loose sand into sandstone. Larsson imagines that one day he could “force the grains of sand to align in certain patterns, certain shapes, having the wind blow out our voids, creating a structure that would change and change again over the course of a decade, a century, a millennium.”

It’s a big departure from current anti-desertification methods, including water conservation, soil management, forestry, sustainable energy, improved land use, wildlife protection, poverty alleviation. Larsson believes that the interior of the dunes along his sandstone wall could be used to achieve multiple goals at once–helping soil remain fertile, providing water and shade, and taking care of plants and animals.

If it is ever constructed, Larsson’s sandstone wall could support the Green Wall Sahara initiative, which aims to plant a shelterbelt of trees across the African continent.

+ Holcim Foundation