Most companies have a reasonable handle on what comes out of their own chimneys, boilers, and company vehicles. But when it comes to the emissions generated by the products they sell, things get murkier fast. These downstream emissions, officially categorized under Scope 3 in the GHG Protocol, often represent the largest slice of a company’s total carbon footprint, yet they’re the slice that gets the least attention. Understanding where they come from, and why they’re so difficult to address, is one of the most important questions in corporate sustainability right now.
So what is the biggest source of downstream emissions across most industries? In the majority of cases, it’s the product use phase: the emissions generated when customers actually use what you’ve sold them. That single category tends to dwarf everything else in the value chain, and it has major implications for how companies think about their sustainability strategy.
Product use phase: the dominant downstream emission driver
The product use phase refers to the greenhouse gas emissions that occur when end users operate or consume a product after purchase. For a car manufacturer, that’s the fuel burned every time someone drives. For an appliance brand, it’s the electricity consumed every time someone runs their dishwasher. For a software company selling energy-intensive data services, it’s the power drawn by the servers and devices running those services.
Across energy-intensive consumer goods, the use phase consistently accounts for the overwhelming majority of a product’s total lifecycle emissions. This matters enormously for Scope 3 reporting, because it means a company’s carbon footprint isn’t primarily defined by how it manufactures things, but by how those things perform in the hands of customers. A product that’s efficient to make but energy-hungry to use can still carry a massive carbon liability across its lifetime.
This is also why product design decisions, not just operational ones, have become central to serious carbon reduction efforts. The choices made in the engineering room often lock in decades of downstream emissions before a single unit ships.
How downstream emissions compare across key industries
The dominance of the product use phase isn’t universal, but it holds across a surprisingly wide range of sectors. The pattern shifts depending on what a company makes and how customers use it.
- Automotive and transportation: For conventional vehicles, tailpipe emissions during use represent the vast majority of lifecycle carbon. Even as electric vehicles grow in market share, the emissions tied to charging still fall under the use phase category.
- Consumer electronics and appliances: Devices that run continuously or frequently, like refrigerators, televisions, or industrial machinery, generate significant use-phase emissions over their operational lifespan. The longer the product life, the larger this footprint grows.
- Financial services: Banks and investment firms face a different version of downstream emissions: the financed emissions tied to the projects and companies they fund. These are captured under a separate Scope 3 category but can still be the dominant source of value chain emissions for large financial institutions.
- Food and beverage: Here, the use phase matters less, but end-of-life processing and customer behavior (like food waste or cooking methods) can still contribute meaningfully to downstream totals.
- Software and technology platforms: As AI-driven and compute-heavy services grow, the energy consumed by users running those services is becoming a more significant downstream consideration.
What ties all of these together is that the biggest downstream source is almost always tied to what the product does, not just what it’s made of. That distinction shapes how companies need to approach their value chain emissions, because it points responsibility upstream, back to product strategy and design, rather than just procurement or logistics. And that’s a harder conversation to have internally.
Why downstream emissions are harder to measure and control
Measuring what happens after a product leaves your facility is genuinely difficult, and it’s worth being honest about why. Unlike upstream emissions, where you can audit suppliers or review energy bills, downstream emissions depend on how thousands or millions of customers actually behave, and that’s not data you can simply pull from a spreadsheet.
There are a few layers to this challenge. First, data availability is patchy. Companies often rely on usage assumptions, average consumption figures, or modeled scenarios rather than real-world data. This introduces uncertainty into any Scope 3 calculation, which in turn makes it harder to set credible reduction targets or track progress over time.
Second, control is limited. You can design a more efficient product, but you can’t control how long customers use it, how often they service it, or whether they use it in ways that increase its energy draw. A highly efficient appliance used 24 hours a day may still generate more lifetime emissions than a less efficient one used sparingly.
Third, organizational accountability is unclear. Downstream emissions don’t fit neatly into any one department’s remit. They sit at the intersection of product development, sustainability, marketing, and customer experience, which means they can fall through the cracks unless someone is explicitly responsible for tracking them.
These challenges don’t make measurement impossible, but they do mean it requires more sophisticated approaches than most companies currently have in place. Life cycle assessment (LCA) methodologies, customer usage data programs, and scenario modeling all play a role, but building that capability takes real investment and expertise.
Strategies to reduce your biggest downstream emission source
Reducing product use phase emissions means working backwards from the customer experience to the design table. The good news is that the levers are real and actionable, even if they require longer-term thinking.
- Design for energy efficiency: The most direct route is building products that consume less energy during operation. This means setting internal efficiency targets at the design stage, not as an afterthought. For many product categories, incremental improvements compound significantly over a product’s lifetime.
- Extend product lifespan: A product that lasts longer spreads its manufacturing emissions over more years of use. More importantly, it delays the need for a replacement, which avoids the emissions tied to producing a new unit. Repairability and durability are underrated sustainability levers.
- Enable smarter customer use: Some companies are investing in tools, apps, or connected features that help customers use products more efficiently. Smart thermostats, energy monitoring dashboards, and usage nudges can reduce real-world consumption without requiring a product redesign.
- Set science-based targets that include Scope 3: Committing to SBTi targets that cover the full value chain creates internal accountability for downstream emissions and signals credibility to external stakeholders. It also forces the kind of cross-functional conversations that tend to get deferred otherwise.
- Use LCA data to prioritize: Life cycle assessments can identify exactly where in a product’s life the emissions are concentrated, helping teams focus effort where it will have the most impact rather than spreading resources too thin.
None of these strategies works in isolation. The companies making the most progress on downstream emissions tend to combine product-level interventions with robust measurement frameworks and clear internal ownership. That combination is harder to build than any single tactic, but it’s what separates genuine progress from sustainability theater.
The role of sustainability expertise in tackling Scope 3
Given the complexity of downstream emissions, it’s no surprise that many organizations find themselves needing external expertise to make headway. But it’s worth being specific about what kind of expertise actually helps here, because the sustainability field is far more specialized than it might appear from the outside.
Scope 3 emissions reduction is its own discipline. A consultant who specializes in CSRD reporting will bring different skills than someone focused on LCA methodology or product carbon footprinting. Similarly, a generalist sustainability consultant may be well-suited to building a high-level strategy, but the technical work of modeling use-phase emissions across a product portfolio typically calls for someone with hands-on experience in that specific area.
For companies working on CDP disclosures or SBTi target-setting that includes Scope 3, the expertise gap can be significant. These frameworks have specific requirements around how downstream emissions are calculated, categorized, and reported, and getting it wrong doesn’t just affect your score. It can undermine the credibility of your entire climate strategy with investors and regulators alike.
The practical implication is that matching the right type of expert to the right problem matters as much as finding someone with general sustainability credentials. A Scope 3 specialist who has worked across multiple industries will bring pattern recognition and methodological rigor that a generalist simply won’t have.
Ready to get the right expertise in your corner?
Downstream emissions are complex, but they’re not unsolvable. What they do require is the right combination of technical knowledge, cross-functional alignment, and a clear sense of where to focus. If your organization is working through Scope 3 for the first time, or trying to go deeper on product use phase emissions, having the right expert alongside you makes a real difference.
That’s exactly what we built Dazzle to do. We match organizations with pre-screened sustainability freelancers who specialize in the specific challenges you’re facing, whether that’s LCA work, Scope 3 strategy, SBTi target-setting, or something else entirely. Our network of 150+ experts is available on a project or interim basis, and we can connect you with the right person within 48 hours. No lengthy procurement processes, no generalists pretending to be specialists. Just the right expertise, when you need it. Reach out to our team and let’s figure out who can help.
If you’re interested in learning more, contact our team of experts today.
