When you are responsible for sustainability, you need to understand the different approaches to assessing and improving the environmental impact of products and processes. One of the key tools in this area is Life Cycle Assessment (LCA). You can use it to evaluate the environmental impacts of a product or service throughout its entire life cycle. And typically, that means from the extraction of raw materials to the disposal of the product at the end of its life.
When writing (or reading!) an LCA, one of the key questions is which stages are considered “the life cycle” for this particular case. What’s covered? What’s the scope? In this context, you will encounter the terms “Cradle to Grave” and “Cradle to Gate” (among others). In this blogpost we will look at each of them, their differences, and when to use each one.
Cradle to Grave
The cradle to grave scope of LCA considers the environmental impacts of a product from the extraction of raw materials to the disposal of the product at the end of its life. The term comes from thinking of the product as having a life (hence the life cycle). Its cradle represents when it’s first born (the extraction of raw materials), and its grave represents when it stops being (when it is discarded). In other words, it should cover every step in that life cycle.
This includes the following stages:
- Production stages: This includes extraction, processing and distribution of raw materials, as well as manufacturing of the product.
- Distribution stages: This includes the transportation, warehousing, wholesale and retail distribution and sales of the product, until it reaches its consumption environment.
- Consumption stages: This includes the use and maintenance of the product along its life cycle, as well as its waste management (the product’s end of life), i.e. its recycling, reuse, or disposal.
By considering the entire life cycle, we gain a comprehensive understanding of the environmental impacts associated with a product. This allows us to identify areas for improvement and implement strategies to reduce those impacts at each stage of the product's life cycle.
For example, let's consider a smartphone's life cycle. The cradle to grave approach would include the extraction of materials like rare earth metals, the manufacturing process, transportation of the product to consumers, its use (including energy consumption and emissions), and ultimately its disposal at the end of its life. Through this scope, we might identify opportunities to improve material efficiency, optimize logistics, reduce energy consumption during use, and mitigate waste generation (e.g. through longer life spans).
You might be thinking: what’s the difference between “Cradle to Grave” and “Life Cycle”? Not much really. Sometimes Cradle to Grave is considered synonymous with LCA. Or the Cradle to Grave scope is called Full Life Cycle. In other words, saying an LCA is Cradle to Grave means it attempts to include everything in the physical life cycle of the product. It tries not to miss anything.
Then why specify that our analysis is Cradle to Grave? Let me introduce you to the other very common scope.
Cradle to Gate
By definition, a Cradle to Gate LCA assesses a partial life cycle of a product. The scope always starts at the very beginning, i.e. the cradle here means the same as in Cradle to Grave. But the end of the scope is, instead, our factory gates (typically before it is distributed to customers). It analyzes only until the point where our product leaves our production facilities.
This scope is admittedly only looking at part of the life cycle of the product. It includes only what we previously described as production stages.
Coming back to the smartphone example, we would be analyzing only the extraction of materials and the manufacturing process. This means that the only opportunities to be identified are those related to more sustainable materials and manufacturing processes.
Wait, isn’t that cheating? When to use each
No, it isn’t cheating: each scope has its place, its advantages and its disadvantages. As long as we are aware of our options, and we are transparent in what we are communicating, both are valuable.
The Cradle to Grave approach provides a fuller picture of a product's environmental impact. One clear case is product developers for consumer products. They will surely want to look at a Cradle to Grave approach, since their designs will affect the entire life cycle of a product. Changing a material may make it more recyclable, or lighter in its transportation.
The Cradle to Gate approach, on the other hand, can be particularly useful when you want to convey information down the value chain. Your production stages are often the only ones you have reliable and precise data about (measured in your factory). If you pass that information to your customers, they can use it to build more reliable LCAs. Your customers care about your cradle to gate impact, and they’ll account for the rest of the life cycle.
Sometimes Cradle to Gate is just the only option available. Consider, for example, materials manufacturers. They have no information or knowledge about how the product will be used, because what they produce can be part of many products! Therefore, including other life cycle stages would be a futile exercise. Only your customers know the life cycle stages after yours, and hence you should focus on delivering that information to them: a Cradle to Gate LCA.
There is a third option: when there is no time or interest in addressing the distribution or consumption stages. If an LCA is only for internal purposes, and we are in the very early stages of our sustainability journey, we might want to start spending most of our resources in having a very good LCA for the production stages, rather than splitting our efforts. This has its risks (namely, we might think our product is better than it is, or focus our sustainability efforts in parts that don’t contribute as much), as long as the person is aware, this can be an effective compromise in the early stages of a company’s sustainability efforts.
For all other cases, or in general to have a better understanding of your product’s environmental impacts, it is advisable to do a Cradle to Grave analysis. Especially if you plan on publishing it. Even a simple model of the distribution and consumption stages can provide insights and clarity.
Other scopes you might find out in the wild
The ideal scope to choose depends on the context, and there are more than those contexts described above. When looking at an LCA, you might encounter other scopes, for example:
- Cradle to Customer: it is not uncommon for a producer to also be responsible for the distribution of their product. Some studies call this slightly extended scope Cradle to Gate, but to differentiate it from the purist definition, it is sometimes referred to as Cradle to Customer or Cradle to Consumer. Given the importance of logistics, in Earthster this is one of the scopes you can select for your data.
- Gate to Gate: this scope represents a very partial view of a life cycle, typically looking at a particular process or processing step of the value chain. A Gate to Gate model can be very useful to model information in a reusable way, since it can be easily plugged into other LCA studies to represent that single process in particular. E.g. you can do a Gate to Gate model of a given factory (per kg processed), and then include it in another LCA as consuming the raw material and that Gate to Gate process. These models can be called Unit Processes (or System Processes if they are compiled into an inventory), and are very useful in creating databases for doing LCA studies.
- Cradle to Cradle: often referred to as a scope, the Cradle to Cradle scope rather invites the LCA practitioner to look beyond the first life cycle of the product, and focus on circularity instead. In practice, its execution is often analogous to that of Cradle to Grave, but with especial attention to closed-loop end of life options, in which new, identical or similar products are created from the waste.
- Transparent scopes: some studies might share the results on different scopes, so that information is both revealing like a Cradle to Grave, and reusable like a Cradle to Gate. Earthster is an example of such: you can have a Cradle to Grave LCA to gain the insights yourself, and share the Cradle to Gate results so your customers can do better LCAs themselves.
Conclusion
Cradle to Gate and Cradle to Grave are the two most important and common scopes for carrying out an LCA. The choice of which scope to use depends on the specific purpose of the study, with Cradle to Grave providing clearer insights about products of which we know the life cycle (and sharing those with consumers), and Cradle to Gate being more powerful for sharing through the value chain.
Ultimately, both approaches contribute to sustainable production and can be used in conjunction to tackle different aspects of a product's life cycle. An effective sustainability strategy involves considering the entire life cycle while also addressing specific areas of concern within the production process.
Earthster makes it easier to get the best out of different LCA scopes, with the advantage of both alternatives. Do you want to know more? Book a demo
