CA45 - Sequester carbon
Planetary boundaries playbook and materials that sequester carbon [softwood aint the best at it]
NEWSWORTHY
🤖 Materials 2050 takes a look at the differences between different Life Cycle Assessment Methods
THE POLL
THE TOPIC
In this newsletter, we talk a lot about carbon emissions from materials.
You probably already know the main contributors in construction but if you forget :
Concrete | 240 - 446 kgCO2e/ m3
Steel | 1, 000 - 2,320 kgCO2e/ metric tonne
XPS Insulation | 5 - 41 kgCO2e/ m2 @ RSI 1
Aluminum Extrusions | 10,250 - 12,700 kgCO2e/ metric tonne
The sad thing is you’d be very hard-pressed to find a modern building without all of these materials in it.
That is why today I want to talk about carbon sequestering, which, IMHO is the future of the building industry.
What is carbon sequestering?
Carbon sequestering in building materials is a relatively simple concept.
And it’s a concept you’ve already been taught, just in a different context.
It’s called photosynthesis.
“Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. - National Geographic ”
It’s basically the OG of carbon capture!
Plants were designed to breathe in CO2 and store it in their fibers.
This natural process removes the CO2 from the atmosphere and uses it to create energy and stores the carbon in its fibers (think all that green and leafy stuff)
That is one of the big benefits of using carbon-storing materials in buildings.
It locks that carbon into our buildings and keeps it from re-entering the atmosphere through the process of rot and decay.
Let’s look at some of the best examples of carbon-storing materials and their potential to absorb atmospheric carbon dioxide.
Softwood | 2-4 Ton/Hect/Yr Potential Uses | Timber, Gluelam, CLT structural members, Cellulose insulations, Cladding
Most of these materials are quite well known when it comes to carbon sequestering and are also the most readily available commercial building materials. They are regionally available in many places, but there are also risks of clear-cut foresting and other over-harvesting concerns. Spec’ing wood just because you think it’s green isn’t a solution.
Straw | 2-4 Ton/Hect/Yr Potential Uses | Insulation [Panelized or Bale], Cladding, Roofing
Straw has amazing potential because it is an agricultural waste product. Currently around the world straw is burnt in large quantities because it is treated as waste. We can use to insulate or clad our buildings. It also has fire-resistant properties and is bug-resistant as well.
Bamboo | 15-17 Ton/Hect/Yr Potential Uses | Structural Elements [Laminated & Raw], Finishes, Furniture, Cladding
Bamboo also has numerous current uses but mostly in North America related to finishes (flooring, wall panels, etc). You may think of this product mostly from Asia, but there is Western Bamboo as well!. Some really interesting potential here because bamboo acts like a grass that will re-grow from the roots after being cut.
Checkout what ReNuTeq is doing with Glue laminated Bamboo Structures.
Hemp | 22-44 Ton/Hect/Yr Potential Uses | Insulation, Fiberboards, Sheathing, Bio-plastics, Finishes
Hemp has soooooo much potential. Just take a look at what Hempitecture is doing. They have great branding and great products including cast-in-place hempcrete, hempwool, and their latest product is Hempbinder.
Algae | 100-250 Ton/Hect/Yr Potential Uses | Cement replacement, Photobioreactors
Algae is the least commercially developed material on this list, but lots of potential nonetheless. Arup did a really interesting project with algae to produce heat through its facade panels.
The amazing thing here is that we are just scratching the surface of biobased materials.
More things will come as the industries continue to grow.
Any other biomaterials I’ve missed? Drop them in the comments.
THE PERSON
Kelly is an Architect, Instructor, and a Senior Fellow with Architecture 2030.. He recently co-founded Ha/f Climate Design and he runs a Research Studio called Ha/f Studio focused on looking at the impacts of embodied carbon in architecture. Highly recommend a follow.