Some sources of greenhouse gases we know about and talk about – power generation and transport for example. Others get less attention, such as meat and dairy, or the need for renewable heat. Another to add to that list is construction materials. Cement production in particular is very energy intensive: 5% of global CO2 emissions are from cement. Bricks are another 2%. If that doesn’t sound too bad, remember that we need to reduce emissions by at least 80% by 2050. If we don’t do anything about it, construction materials will be a massive slice of the carbon budget in a few decades time.
There are a variety of solutions. One is to use biomass to fire the kilns needed for processing limestone. Another is to find alternatives to limestone, such as concrete mixes that use fly ash. Hempcrete is suitable for some applications, but isn’t load bearing. Carbon capture and storage is another possibility for reducing the emissions of cement production. All kinds of alternative materials exist for eco-building, from straw bale walls to mud construction, so there’s no shortage of solutions.
Here’s the most radical suggestion I’ve heard so far: perhaps we could grow the materials we need instead.
bioMASON have applied biotechnology to construction materials. They put aggregates into a frame, usually sand. They add water and a mixture of micro-organisms. These micro-organisms are fed, they grow, and they bind the aggregate together into a brick. It essentially replicates the process that takes place in coral formation, a naturally occurring cement. It’s just been accelerated, creating a brick in 2-5 days.
Unlike traditional kilns, there’s no massive heat requirements for producing bricks, or for cement if you’re using breeze-blocks. No fossil fuels are required. It’s a much more ecologically friendly mode of production.
bioMASON aren’t at full scale production yet, but they don’t intend to build a great big factory. Rather, the ultimate goal is to send customers what they need to grow their own bricks on site. Just add water. It’s probably too early to tell whether or not its going to be a viable solution, but it’s certainly an extraordinary idea.
- I’m also reminded of how to grow packaging materials