Bacteria Could Help "Glue" Sahara Sands Together?!?

What kind of madness is this? We spend the better part of our lives fighting off bacterial invaders, so why would we now turn around and invite them over for a cup of tea...in the Sahara of all places? To understand Swedish architecture student Magnus Larsson's ambitious proposal a little better -- namely, erecting a 6,000km-long bacteria solidified sandstone wall from one side of the Sahara desert to the other -- it's first necessary to comprehend why we would want to mess with Mother Nature on such a grand scale. (We'll get to the bacteria part of the equation in just a bit.) While many of us have been living me-centric lives amid concrete jungles and urban city centers, we've been rather clueless about what has been going on in the rest of the world.

We may rally around the green movement and talk about our admirable efforts to recycle and go veggie for a day, but those causes somehow seem naively small in scope when you consider the vast list of environmental problems that persist across the globe. I'm among the guilty -- I had no idea that one of the natural wonders of our world, the Sahara, has been suffering the effects of our inattention for decades now. Due to human over-exploitation, over-hunting and widespread biodiversity loss, the infamous desert -- which stretches from Northern Africa to the Red Sea and the fringes of the Atlantic Ocean -- has suffered a serious blow to its fragile ecological balance.  The 3,500,000 square mile region now lacks the majority of the wildlife and botanicals that it once had, and as a result, its sands have been encroaching on southern Africa at an estimated 30 miles each year.  This has set off red flags because through this desertification process, essential temperate ecoregions are slowly but surely being taken over.

Magnus Larsson isn't the first to propose a man-made barrier to stall the sand encroachment described above -- the Community of Sahel–Saharan States (Cen-Sad) summit on rural development and food security in Cotonou, Beni launched the 'Great Green Wall' project just one year ago. Their tree planting efforts, expected to take several years to complete, will create locally sourced tree "belts" that span 7,000 kilometres long and 15 kilometres wide on the east and west sides of Africa. A previous tree planting project, already completed, seeded areas in Chad, Djibouti, Eritrea, Ethiopia and Sudan.

Magnus Larsson, however, is the first (to my knowledge) to propose a solution via bacillus pasteurii, a readily available marsh and wetland microorganism that conveniently transforms loose sand granules into firm sandstone monuments. His seemingly mad scientist plan earned him the top prize in Holcim Awards "Next Generation" sustainable construction competition, so perhaps his plan is more Dr. Jekyll than Mr. Hyde? After considering the great success that UC-Davis' Soil Interactions Lab has had using bacteria to solidify problematic soils that are prone to degrading -- coupled with what already happens in the natural world when that bacteria is present -- it does stand to reason that this biological architectural construction can be applied on a massive eco-scale to aid the Sahara.

Larson suggests flushing a particular bacteria through loose sand, and says that in a matter of 24 hours, a biological reaction will transform individual granules into firm sandstone structures. He adds that, "it would take about a week to saturate the sand enough to make the structure habitable. A balloon-like pneumatic structure filled with bacillus pasteurii would then be released into the sand and allowed to solidify into a permacultural architecture." He has clearly done his homework judging by the following comments, "Traditional anti-desertification methods include the planting of trees and cacti, the cultivation of grasses and shrubs, and the construction of sand-catching fences and walls. More ambitious projects have ventured into the development of agriculture and livestock, water conservation, soil management, forestry, sustainable energy, improved land use, wildlife protection, poverty alleviation, and so on. This project, apart from utilising a completely new way of turning sand into sandstone, incorporates all of the above. Inside the dunes, we can take care of our plants and animals, find water and shade, help the soil remain fertile, care for the trees, and so on. In this way, it's an environmental project that hopefully provides an innovation for other architects/builders to use and copy time and time again."

These "solidified dunes," would also, "support the existing Green Wall Sahara initiative: 24 African countries coming together to plant a shelterbelt of trees right across the continent, from Mauritania in the west to Djibouti in the east, in order to mitigate against the encroaching desert." What do you think? Is this a brilliant plan or a dangerous walk on the geo-engineering side? It is certainly original and extremely well thought out (considering the extensive range of illustrations and descriptions he posted on Flickr -- flickr.com/photos/bldgblog/sets/72157612777908074/detail/), but does it seem wise to put into action? What negative consequences do you think could emerge from this project?