Getting a science-based target approved sounds straightforward until you actually sit down to do it. The Science Based Targets initiative (SBTi) has become the gold standard for corporate climate commitments, and for good reason. But when it comes to scope 3 emissions, the process gets genuinely complex. You’re no longer just measuring what happens inside your own walls. You’re accounting for everything upstream and downstream: suppliers, logistics partners, product use, and end-of-life disposal. For most companies, that’s where more than 70% of their total emissions sit.
This guide walks through the full journey of setting a credible, SBTi-validated scope 3 target, from understanding why it’s so difficult to actually getting your suppliers to move. Whether you’re starting from scratch or trying to make sense of where your current effort has stalled, there’s something useful here for every stage of the process.
Why scope 3 is the hardest part of SBTi compliance
Scope 3 emissions are notoriously difficult because they fall outside your direct operational control. Unlike scope 1 and 2, where you own the assets producing the emissions, scope 3 spans a vast network of third parties, each with their own systems, incentives, and data quality issues. The SBTi Corporate Standard requires companies to set a scope 3 target if those emissions represent 40% or more of their total footprint, which means most companies can’t simply skip this part.
The challenge isn’t just data collection. It’s the sheer breadth of what qualifies as scope 3. The GHG Protocol defines 15 categories, ranging from purchased goods and services (category 1) to the use of sold products (category 11) and investments (category 15). Each category has its own measurement approach, data availability issues, and level of influence you can realistically exert. Deciding which categories are material to your business, and then setting a credible reduction pathway for them, requires both technical expertise and strategic judgment. That combination is rarer than it sounds.
Mapping your scope 3 emissions landscape
Before setting any target, you need to know what you’re actually dealing with. A scope 3 screening exercise maps your emissions across all relevant categories and identifies where the biggest concentrations sit. This is the foundation everything else builds on, and skipping it leads to targets that are either too narrow to be credible or too broad to be actionable.
A good screening uses spend-based or activity-based data to estimate emissions across categories, then flags which ones are material. Materiality here doesn’t just mean size. It also means relevance to your sector and your ability to influence reductions. For a consumer goods company, category 1 (purchased goods) and category 11 (use of sold products) will almost always dominate. For a financial institution, category 15 (investments) is often the biggest story. The SBTi expects you to cover categories that together represent a significant portion of your total scope 3 footprint, so this mapping exercise directly shapes the scope of your target.
It’s also worth flagging which categories you’re excluding and why. SBTi reviewers look for transparency in boundary-setting decisions. If you’re leaving out a category, you need a documented reason, not just a gap in your spreadsheet.
Choosing the right target-setting method
Once you know which categories you’re covering, you need to pick a method for calculating your reduction target. The SBTi offers several options, and the right one depends on the category, your data quality, and the level of ambition you’re committing to.
- Supplier engagement target: This approach requires a set percentage of your suppliers (by spend or emissions) to have their own science-based targets. It’s commonly used for category 1 and works well when you have significant purchasing leverage over a concentrated supplier base.
- Customer engagement target: Used for downstream categories like category 11, this method sets goals around engaging customers or end users in reducing emissions during product use. It’s relevant for companies whose products generate significant operational emissions.
- Physical intensity target: This sets a reduction in emissions per unit of output, such as tonnes of CO2 per tonne of product. It’s useful when absolute reductions are difficult to model due to anticipated business growth.
- Absolute contraction approach: The most straightforward method, requiring an absolute reduction in total scope 3 emissions over a defined period. The SBTi specifies minimum reduction rates aligned with 1.5°C or well-below-2°C pathways.
Each method has trade-offs. Supplier engagement targets are practical but depend on your supply chain’s willingness to act. Absolute contraction targets are the most credible externally but require high-quality baseline data. Physical intensity targets can mask absolute emission increases if your business grows. The method you choose signals something about your level of ambition, so it’s worth thinking carefully about what each choice communicates to stakeholders, customers, and SBTi reviewers alike. Most companies end up using a combination of methods across different categories rather than a single approach for everything.
Building a credible data foundation for your target
A scope 3 target is only as credible as the data behind it. This is where many companies run into trouble. Spend-based emission factors, which are the most commonly used starting point, introduce significant uncertainty. They estimate emissions based on how much money you spent with a supplier rather than the actual emissions that supplier generated. For screening purposes, that’s fine. For a validated SBTi target, it’s not always enough.
The SBTi doesn’t require primary supplier data for every category, but it does expect your baseline to be robust and your methodology to be documented. That means being clear about which emission factors you used, where they came from, and how you’ve handled gaps. For high-impact categories, moving toward activity-based data, such as actual energy consumption or production volumes from key suppliers, significantly strengthens your submission.
It’s also important to set a credible base year. The SBTi allows base years as far back as 2015 in some cases, but your base year needs to be representative of your normal operations and supported by verifiable data. If your base year emissions look unusually low due to a one-off operational change, reviewers will flag it. Getting the base year right matters more than most companies realize at the start of this process.
Submitting and validating your target with SBTi
The submission process itself has a few distinct stages, and understanding them upfront saves a lot of back-and-forth. Once you’ve defined your target boundary, chosen your methods, and documented your baseline, you submit a target letter to the SBTi through their online portal. This letter outlines your commitment and the key parameters of your target.
From there, the SBTi conducts a technical review. This is where they check whether your target meets the minimum criteria for ambition, boundary coverage, and methodological consistency. Reviewers may come back with questions or requests for clarification, particularly around scope 3 boundary decisions and the data quality of your baseline. It’s not uncommon to go through one or two rounds of revision before validation is confirmed. The process takes time, so building in a realistic buffer before any public announcement is sensible.
Once validated, your target is published on the SBTi website and you’re expected to report progress annually. That ongoing reporting obligation is something worth planning for operationally before you submit, not after.
Turning a validated target into supplier action
Getting a target validated is a real achievement, but it doesn’t automatically reduce a single tonne of emissions. The harder work starts after validation, particularly for companies using supplier engagement targets. Moving suppliers from awareness to action requires a structured approach, and the timeline is often longer than companies expect.
Effective supplier engagement typically involves a few interconnected efforts. Start by segmenting your supply base by emissions impact and strategic importance. High-impact, strategic suppliers deserve a direct, collaborative approach. Lower-impact suppliers can be reached through scaled programs, such as training initiatives, shared tools, or industry coalitions. Embedding scope 3 expectations into procurement criteria, whether through supplier codes of conduct, RFP requirements, or contract terms, gives you a structural lever beyond relationship-based conversations.
Tracking progress matters too. If your target commits you to a certain percentage of suppliers having SBTi-validated targets by a given year, you need a system for monitoring where each supplier stands. Many companies underinvest in this tracking infrastructure and then struggle to demonstrate progress at reporting time. Building that system early, ideally as part of your existing supplier management processes, makes annual reporting far less painful.
The reality is that scope 3 decarbonization is a long game. Targets set the direction, but the actual emission reductions come from sustained engagement, procurement decisions, and the gradual shift of your supply chain toward lower-carbon practices. Companies that treat their validated target as the finish line tend to fall behind. Those that treat it as the starting gun tend to make real progress.
Ready to move faster on your scope 3 target?
Setting a credible science-based target for scope 3 emissions involves a lot of moving parts: category screening, method selection, data quality, submission logistics, and supplier engagement. It’s genuinely complex work, and the stakes are high. Getting it wrong doesn’t just delay your SBTi validation. It can undermine your credibility with customers, investors, and regulators who are paying closer attention to climate commitments than ever before.
That’s where we come in. At Dazzle, we match organizations with pre-screened sustainability freelancers who specialize in exactly this kind of work, whether that’s a scope 3 emissions reduction consultant, an SBTi submission specialist, or someone who can help build out your supplier engagement program. You can start working with the right expert within 48 hours, without the overhead of a traditional consultancy. If you’re ready to get moving, reach out to our team and we’ll match you with the right person for your specific challenge.
If you’re interested in learning more, contact our team of experts today.
