Sheep & Wool and the Carbon Cycle
Besides the fact that wool is comfortable, insulating, fire resistant, flexible and odour resistant - it is also a superior choice for our textiles when we look at the environmental impact or life cycle assessment. Wool is made up of 50% organic carbon - so how can that contribute to climate change solutions?
Sheep and The Carbon Cycle
Carbon dioxide (CO2) is a natural part of our atmosphere and is taken in by green leaf plants. Through the process of photosynthesis the 2 oxygen molecules are separated from the carbon and oxygen is released back into the atmosphere for us to breathe. The carbon is then transformed into a simple carbohydrate that the plant uses to feed its structure and the soil ecosystem through its roots.
When sheep, alpacas, goats, llamas and other ruminants eat those plants they are taking that carbon and turning it into various types of protein – like wool or fibre. That wool or fibre is sheared and turned into our clothing or other textiles and (hopefully) used for many years.
When that clothing is no longer useable it can be composted – where that carbon (still fully contained in the wool fibres) will be returned to the soil along with other nutrients to feed the soil microbes and begin growing other plants and starting the cycle again.
So not only are sheep taking carbon out of the atmosphere and turning it into an incredible fibre that we can turn into clothing, but sheep can also contribute to the health of our grasslands and ecosystems. If farmers and land stewards can employ methods that help build more soil organic matter, our soils have the opportunity to sequester more carbon from that atmosphere, increase water holding capacity - decreasing our reliance on aquifers and other water sources, and provide healthy ecosystems for other species.
While some of the atmospheric carbon taken in by plants is utilized by animals to grow wool and fibre, the rest of the carbon stays in the soil and is used to feed the microbes in the soil and the development of mycorrhizal fungi. They work together to produce humus - the rich soil that is essential for growing healthy plants. Carbon that is stored in humus can stay sequestered in the soil for a very long time. Managed grazing of sheep on grasslands and pasture can encourage plant growth and increased draw down of carbon into roots and soil. As they turn grass into wool and encourage plant growth, they also leave nitrogen rich fertilizer, in the form of manure that further builds health and resilience in the soils.
When shepherds utilize grazing animals to imitate that movement of wild ruminants, or historical herds of bison through managed, adaptive or planned grazing they provide the necessary disturbance to reduce dead grass or overgrown forage and allow new growth. Sheep can be used to clear out overgrown brush to also prevent wildfire prone areas and keep invasive species at bay. When we as consumers understand the vital role that sheep can play in building healthy soils, resilient grasslands and biologically diverse ecosystems - we can support and purchase fibre, clothing, and yarn from the shepherds in our region who are committed to the vitality of our land.
(Text by Anna Hunter - from Sheep, Shepherd & Land)
Once I learned that wool was made up of 50% organic carbon I started thinking about the fact that when we wear wool we are little ‘carbon sinks’ walking around - I wanted to run some numbers.
I calculated that in a full year of business we are sequestering 2571 Kg of carbon dioxide equivalents (CO2-e) in the wool that we grow, produce and sell as textiles. We put another According to the Environmental Protection Agency in the US this is equivalent to:
Driving a gas powered vehicle for 6379 miles
6 barrels of oil consumed
2843 pounds of coal burned
289 gallons of gasoline consumed
.5 of a homes electricity for a year
This amount of Carbon Sequestration is the same as:
42 tree seedling grown for 10 years
3 acres of forest in 1 year.
You might be wondering how I came up with these numbers? I will try and break it down for you:
Organic carbon makes up 50% of the weight of wool.
Wool will continue to hang on to this carbon during its lifetime, and hopefully when the item is discarded it will be composted where that carbon can return to the soil.
I have to admit, I wish the number was higher. And of course this calculation is just the CO2 that is stored in wool and isn't calculating the emissions created by growing and processing that wool. But it is an incredible starting place to look at the impact that our clothing choices can have on carbon emissions and sequestration. Cotton and Linen are only 40% organic carbon and synthetic fibres are actually de-sequestering carbon out of the ground.
After working with holistic management this summer we did some soil testing to measure how much carbon is in our soils, so hopefully we will have those numbers to include in our overall climate plan for our farm and business. Because our sheep and the farms that we choose to work with are raised in extensive pasture systems the diet is predominantly grasses, legumes and forbs. Plants convert CO2 from the atmosphere and turn it into energy through the process of photosynthesis. This energy is what sheep use to grow wool. Thus, the carbon that is sequestered in your wool yarn or fibre has been taken out of the atmosphere 1-2 years earlier.
What do you think? Do these numbers matter? How much more impact would our carbon sequestering wool goods have if we prioritized local, regional processing rather than global shipping and processing? Should we be holding all businesses to account for what their emissions 'balance sheets' look like?
*** CO2-e calculations come from the International Wool Textile Organization