2023 Life Cycle Assessment: Calculating the Emissions of our Products
INTRODUCTION
We're on a mission to help gardeners nurture soil, plant, and planet health. We work to make sustainable gardening as easy as possible by offering win-wins: eco-friendly choices that don't sacrifice performance. Our products celebrate the joy of growing plants without harming nature because we believe that gardening shouldn’t come at the expense of the Earth. To accomplish this, we’ve tested and perfected new soil options that have been proven to pull carbon out of the atmosphere.
Soil has an amazing ability to store atmospheric carbon. In fact, the Earth’s soil holds four times more carbon than its plants. However, as lifelong gardeners, we were frustrated and disappointed to realize that most mainstream soil products, especially ones made with peat, have a significant carbon footprint. We knew there had to be a better way. So, we've specifically designed our products from the ground up to be better for your plants and better for the planet.
To accomplish our mission, we’ve committed to making the highest quality soils with the lowest possible environmental footprint. Our goal is to minimize our carbon footprint from the get-go, and lay a climate centered foundation to keep us poised for smart growth as we scale. Before we can work to reduce our impact, we have to fully understand what that impact is, and identify opportunities to reduce emissions or waste throughout our supply chain. Measurement is always our first step in a continuous effort to improve and minimize our environmental impact.
This is why we’ve taken the time to conduct a Life Cycle Analysis (LCA) of our two products:
- Indoor Potting Mix
- Cacti Potting Mix
A Life Cycle Analysis (LCA) is a comprehensive assessment of the emissions generated when manufacturing a single unit of a product. We evaluate the carbon impact produced at each stage of the product's "life cycle." The life cycle commences when the product's raw materials are extracted from the earth, covers every phase of its production and distribution across the supply chain, and concludes when our customers use and eventually discard the item.
After conducting the LCA, we utilize our understanding of our overall impact to take tangible actions towards achieving carbon neutrality. For our company, this entails procuring carbon credits to ensure all of our products are net carbon neutral.
In accordance with standard LCA methodology, we’ve measured the net emissions created across the following 5 key stages:
For these LCA’s, our impact is measured in terms of Carbon Emissions because this best describes the total amount of Carbon Dioxide (CO2) emitted throughout our product’s life cycle. You will see this listed as “CO2 eq,” or the equivalent emissions in kilograms of CO2.
DATA
We’ve collected data from a variety of sources to measure the carbon impacts of our Indoor Potting Mix for each component, throughout all phases of the product life cycle.
When we considered the impacts of our packaging and final shipment to customers, we trusted the data provided by our suppliers, our fulfillment partners, the EcoInvent database, and Puro Earth, whom we’ve chosen to work with on account of their commitment to sustainability.
Now, let’s take a look at the methods we used to measure our impact for all of our products.
PRODUCTION
The first step of the LCA was to measure the carbon emitted when producing each ingredient that makes up our potting mixes
When considering both our Indoor Potting Mix and our Cacti Potting Mix, our full list of ingredients is:
- Biochar
- Compost
- Pine Bark Fines
- Mycorrhizae
- Pumice
- Sand
Biochar
Biochar is our hero ingredient and helps us fulfill our mission: to offer customers a soil product that not only improves soil health and plant growth, but helps mitigate climate change through a production process that captures and stores high amounts of atmospheric carbon dioxide. Encouraging studies like this one have shed light on how and why this process is so effective.
Biochar's potential to remove billions of tons of carbon from the atmosphere each year, through the process of carbon sequestration, is well established according to experts. Harnessing this potential is at the heart of our mission. We are committed to doing our part to support the growth of the biochar industry, as its expansion translates directly to an increase in carbon sequestration.
Biochar’s superpower arises from transforming waste materials into a carbon-rich soil enhancer. All organic materials, such as the wood waste we obtain, are composed of carbon. When left to decompose over extended periods, this carbon gradually dissipates into the atmosphere. We can prevent this by creating biochar instead of letting the organic waste go to a landfill and decay, locking the carbon inside and reducing the potential for carbon emissions. So when we think about the net impact of producing biochar for our Potting Mix, it’s important to consider how much we avoided simply by producing biochar itself.
Rosy Soil's biochar is produced using pyrolysis, a process that involves heating wood scraps to high temperatures in an oxygen-deprived environment. Since there's no oxygen, the wood scraps can't ignite, which would otherwise release carbon into the atmosphere. Instead, the wood scraps remain in a solid form and retain all the carbon inside. Once the biochar is generated, the organic carbon becomes much more resistant to decay, as it is converted into a porous, carbon-dense material with a high surface area. This makes it an excellent soil nutrient holder, water retainer, and promoter of plant growth. Moreover, when we blend it with the other components in our potting mix, it yields a top-quality product specifically designed to support plant growth.
At Rosy, we believe in collaborating with partners who share our dedication to carbon sequestration. That's why we choose to work with folks who follow sustainable production practices and, most importantly, have their carbon footprint certified by established partners like Puro. Through these partnerships, we can guarantee that our biochar ingredient is verified net carbon neutral by trustworthy third parties. Opting for a certified supplier allows us to achieve our target of zero carbon impact for our main ingredient, resulting in an impact of 0 kg CO2 eq.
Compost
Compost, when combined with our biochar, makes up the base of our blends. We’ve sourced compost from a local operation, where green and wood waste scraps are collected into large piles. As it composts, each pile becomes hot enough to break down those inputs into high-quality organic material. After it’s watered and stirred regularly over the course of months, the result is a nutrient-rich soil ingredient.
We used the EcoInvent database to calculate the carbon emitted when producing the compost input for each product.
Pine Bark Fines
Pine bark fines are created by finely grinding the bark of pine trees. This process results in a pulverized substance that is even finer than wood chips. At Rosy, we source our pine bark fines from a supplier who uses diverted pine bark from lumber mill waste. This ensures that we are utilizing a byproduct of the lumber industry and reducing waste.
To calculate the carbon emitted during the process used to grind that diverted bark, we used the EcoInvent database.
Mycorrhizal Fungi
Although mycorrhizal fungi make up a small fraction of our potting soil, their presence brings enormous benefits. It’s all due to the mutually beneficial relationship between these fungi and root systems. Plants entice mycorrhizal fungi to attach to their roots by releasing sugars. In return, the thread-like structures of these fungi increase the area, and consequently, the amount of nutrients and water available to the plant. With the help of these fungi, plants can reach far down into the soil for those typically hard-to-reach nutrients like phosphorus, calcium, and zinc. What’s more, mycorrhizal fungi have been shown to play a key role in natural soil sequestration, helping to store carbon in their structures.
This ingredient is great from the standpoint of sustainable production as well. It’s produced by growing a plant, often some kind of grass, adding a spore of the fungus into the soil, and allowing fungi to grow using the plant as the medium. Therefore, manufacturing this ingredient is little more than the process used to grow plants.
Of course, there are some very minor carbon emissions produced by the process of farming, mainly due to the energy used when operating equipment and disturbing the soil. To calculate these emissions, we also used the EcoInvent database.
Sand
Sand has large grain size and coarse texture. For us, that all means good drainage in our soil mix. When considering the impact of sand production, it’s all about the energy used to collect and dry it.
We used the EcoInvent database to capture the emissions of both those activities.
Pumice
Pumice is a naturally occurring volcanic rock that is lightweight and porous. We use it as a low-carbon alternative to perlite, to ensure our soil has good drainage and aeration. It’s made by taking fully formed pumice rocks and grinding them into a fine powder.
To calculate the carbon impact created by pumice in our mix, we used the EcoInvent database to capture the emissions of extracting the rocks, transporting those to the quarry, and grinding those at the quarry.
PACKAGING
We source our packaging from a sustainability-focused packaging company, and have used their own LCA for this section. The packaging is a fully-recyclable, carbon-negative bag that mimics plastic, but is made from sugar cane. We ensure the impact created by our packaging is carbon negative by using this material, because it diverts more carbon from the atmosphere than it adds.
According to our bag supplier’s calculations, the production of the bag used in a single unit carries a carbon negative impact of -.01 kg CO2 eq.
TRANSPORT
The transport stage includes the carbon emitted by two transport phases:
- Ingredients moved from our suppliers to our manufacturing site
- Finished product shipped to the end consumer
To calculate the impact produced by our transport, we accounted for the distance traveled, the weight of the ingredient, and the transportation method.
To keep the carbon impact of transportation as low as possible, we’ve partnered with UPS carbon neutral shipments for our retailers and Shopify’s Carbon Removal program for our ecommerce customers.
USE AND END OF LIFE
Measuring the carbon impact of the use of our product was a challenge of our LCA as there is not much public data available for gardening activities. That said, we defined “use” as all that occurs after our customers add a bag of our soil to their soil. We’re confident this number is very low because our data sources for the production phase as well as packaging have already accounted for much of these potential emissions.
The final stage of the LCA is called the “End of Life.” This accounts for the potential carbon impact produced when packaging or the product itself is discarded as waste.
For our Potting Mix, we’ll consider two variables:
- Discarded Packaging
- Discarded Potting Mix
Discarded Packaging
As mentioned, our packaging is fully recyclable. By providing clear instructions about recycling our packaging online and on our label, we make it easy for our customers to recycle 100% of it.
But even if customers do not recycle our packaging correctly, its particular plant-based ingredients ensure that, once in the landfill, it gradually decays into biogenic carbon instead of generating greenhouse gas emissions.
Our packaging supplier has accounted for both scenarios in their LCA , so the emissions in this stage are already covered in the previously outlined calculations of packaging production.
Discarded Potting Mix
To better understand what our customers are doing with the potting mix they do not use, we’ve conducted a survey.
|
Response |
Percent |
|
Throw in trash |
5.1% |
|
Compost |
16.2% |
|
Use as topsoil/throw in the garden |
10.8% |
|
Save for future use |
67.5% |
Considering the “compost” and “use as topsoil/throw in the garden” options, there are also no carbon emissions, as both ultimately end up back in the soil. The only true end of life carbon emissions result from the “throw in trash” response, which we’re thrilled to see is the smallest portion of responses, and have accounted for accordingly.
RESULTS
Indoor Potting Mix -- 4 qt.
|
Ingredient |
Production (kg CO2) |
Transportation: Ingredients > Manufacturer (kg CO2) |
Transportation: Manufacturer > Consumer (kg CO2) |
Packaging (kg CO2) |
End of Life (kg CO2) |
|
Biochar |
0.000 |
0.000 |
0.000 |
-0.010 |
0.004 |
|
Compost |
0.034 |
0.112 |
|||
|
Pine Bark Fines |
0.015 |
0.072 |
|||
|
Fungus |
0.003 |
0.015 |
|||
|
0.245 |
|||||
Indoor Potting Mix -- 8 qt.
|
Ingredient |
Production (kg CO2) |
Transportation: Ingredients > Manufacturer (kg CO2) |
Transportation: Manufacturer > Consumer (kg CO2) |
Packaging (kg CO2) |
End of Life (kg CO2) |
|
Biochar |
0.000 |
0.000 |
0.000 |
-0.010 |
0.008 |
|
Compost |
0.068 |
0.224 |
|||
|
Pine Bark Fines |
0.030 |
0.144 |
|||
|
Fungus |
0.006 |
0.030 |
|||
|
0.500 |
|||||
Cactus Potting Mix -- 4 qt.
|
Ingredient |
Production (kg CO2) |
Transportation: Ingredients > Manufacturer (kg CO2) |
Transportation: Manufacturer > Consumer (kg CO2) |
Packaging (kg CO2) |
End of Life (kg CO2) |
|
Biochar |
0.000 |
0.000 |
0.000 |
-0.010 |
0.008 |
|
Compost |
0.013 |
0.046 |
|||
|
Pine Bark Fines |
0.015 |
0.072 |
|||
|
Fungus |
0.003 |
0.015 |
|||
|
Pumice |
0.005 |
1.075 |
|||
|
Sand |
0.007 |
0.027 |
|||
|
1.276 |
|||||
Cactus Potting Mix -- 8 qt.
|
Ingredient |
Production (kg CO2) |
Transportation: Ingredients > Manufacturer (kg CO2) |
Transportation: Manufacturer > Consumer (kg CO2) |
Packaging (kg CO2) |
End of Life (kg CO2) |
|
Biochar |
0.000 |
0.000 |
0.000 |
-0.010 |
0.016 |
|
Compost |
0.026 |
0.092 |
|||
|
Pine Bark Fines |
0.030 |
0.144 |
|||
|
Fungus |
0.006 |
0.030 |
|||
|
Pumice |
0.010 |
2.150 |
|||
|
Sand |
0.014 |
0.054 |
|||
|
2.562 |
|||||
ACHIEVING NET NEUTRAL
At Rosy Soil, we are committed to removing as much CO2 from the atmosphere as we possibly can. To do so, we take a comprehensive approach that involves calculating the carbon impact of every product we sell and tracking how many we sell. We then purchase carbon offsets through carbon marketplaces to account for any carbon emissions that we were not able to eliminate through our sustainable production practices.
Additionally, the use of biochar in our mixes helps to sequester even more carbon, as demonstrated by this study. By combining the carbon offsets we purchase with the carbon sequestered by the biochar, we are able to achieve a net neutral impact, and even go beyond that by helping to remove carbon from the atmosphere. In this way, we pride ourselves as playing a core function within the carbon sequestration ecosystem, helping to sequester considerable carbon with every product we sell. We believe that this approach is essential to mitigating the impact of climate change and protecting our planet for future generations.
The full impact of our products can be found in the table below:
|
SKU |
Biochar Mass |
CO2 Sequestered via Biochar (kg) |
CO2 Sequestered via Offsets (kg) |
Total CO2 Sequestered (kg) |
|
Indoor — 4qt |
0.120 |
0.360 |
0.245 |
0.605 |
|
Indoor — 8qt |
0.240 |
0.720 |
0.500 |
1.220 |
|
Cactus — 4 qt |
0.060 |
0.180 |
1.276 |
1.456 |
|
Cactus — 8 qt |
0.120 |
0.360 |
2.562 |
2.922 |
COMPARED TO TRADITIONAL
A traditional bag of potting mix typically includes 70% peat moss, 10% perlite, 10% fertilizer, and 10% compost, all packaged in a polyethylene plastic bag.
We can’t reasonably presume many of the data points required to complete an entire LCA of a traditional, non-biochar containing alternative. (We hope other soil companies will be encouraged to produce their own LCA!) That said, by looking at the carbon impact of production alone demonstrates how minimal Rosy Soil's carbon impact is in comparison.
When we consider a bag of traditional potting mix of the same weight as our Indoor Potting Mix (8 qt.), for example, and measure the impact of producing each of the above ingredients using the EcoInvent database, we see a carbon impact of +3.38 kg CO2. That’s over five times the impact of .500 CO2 created by our product.
These numbers are a calculation of one bag of potting mix. But it's useful to consider the process on a larger scale.
Many potting mixes are made with a large majority of peat moss. Although peat moss is a common growth medium, its harvest releases high quantities of carbon into the atmosphere. According to the International Union for Conservation of Nature, although harvested peatlands only account for a small percentage of land surface, they are responsible for the release of 1.9 gigatonnes of CO2eq annually.
By opting for biochar instead, we support an industry that has the potential to sequester 2.2-4.4 gigatons of CO2 per year by 2050.
CONCLUSION
It’s important to remember that this evaluation is the first step in a process of improvement that never ends. As we grow and learn more about carbon impacts and how to better measure them, we’ll improve the precision of our understanding within our supply chain. And with greater certainty we’ll be able to make the right changes to reduce our footprint even more.
And for that, we need your help. We want to hear from our customers who may have questions or concerns. We hope to continue to meet with experts who are well-versed in sustainability. What are we doing right? Where are we missing? Let us know how we’re doing so we can collaborate and continue to improve on our mission. We couldn’t do it without you!