From hotspots to action: supply chain decarbonization, simplified

For many companies, the biggest climate risks and opportunities sit outside their walls. Scope 3 emissions, which are largely the emissions from the products and services you buy, and the use of your products by customers, often dwarf everything else. That’s why companies generally consider their scope 3 emissions to be the toughest sustainability nut to crack. But, as regulation tightens and climate risk becomes business risk, supply chain decarbonization has shifted from a nice-to-have to a board-level imperative. 

That being the case, where should your company begin? 

Start fast 

“Momentum starts with pragmatic baselining, focused engagement, and clear governance,” says Aaron Leow, Senior Manager for Sustainability and Clean Energy at Trio. “You need a way to get moving fast, then a system to keep moving.” 

Leow’s first recommendation is to prioritize speed over perfection. Instead of waiting to compile perfect data, he recommends a spend-based estimate to locate hotspots, which are typically suppliers and categories with outsized footprints. Free resources, such as EEIO (environmentally-extended input-output) models, can rapidly identify emissions per dollar spent, offering a kind of triage to see where firms should look first. 

Get precise 

Precision, Leow says, comes next. Spend-based estimates can help a company get started, but once a firm needs to track progress, supplier-specific data is required, in order to capture reductions in accounted-for emissions. This, Leow suggests, is where collaboration pays off. “I always recommend joining an industry bandwagon,” he says. “If you can combine data requests with peers, you reduce the reporting burden on suppliers, increase response rates and, most importantly, align on training so the data is accurate.” 

Some examples of such bandwagons are Supplier's Partnership’s Automotive Climate Action Questionnaire Framework, the CDP Supply Chain, and initiatives under the PACT Methodology for Product Carbon Footprints. 

Prioritize by impact 

Prioritization, Leow suggests, is a matter of both math and strategy, starting with emissions concentration, overlaid by business importance. “Your highest-emitting suppliers should be engaged first,” Leow notes. Typically, he says, companies look at the top 90% or top 67% of emissions to align with SBTi requirements. From there, firms work with procurement to identify strategic partners. High-emitting, long-term partners are a must-engage, while early “hotspots,” flagged by spend, can be confirmed and refined as supplier-specific data comes in. 

Because supplier maturity varies widely, Trio structures enablement by stage. Beginners start at a “learn and socialize” phase, with introductory webinars and white papers to help them understand options and build internal buy-in. 

Firms at the intermediate stage need direction, not just information. “They’re asking, ‘Which levers fit me?’” Leow says. Cohorts and step-by-step playbooks that assess feasibility give such firms a path forward and enable them to prepare. At this stage, suppliers should codify a decarbonization strategy. To this end, Trio conducts Decarbonization Lever Assessments to pinpoint clients’ areas of greatest opportunity for emissions reductions, along with identifying the capital and resourcing needs for such a plan. 

For advanced suppliers, it’s all about execution. At this action phase, cohorts — small groups of suppliers who are part of the same customer’s supplier engagement program — offer a powerful mechanism to move suppliers ahead. Such programs succeed when ownership and escalation are unambiguous and the basics are in place. This means tracking supplier participation, defining roles across sustainability, procurement, leadership, and consultants, and establishing a clear escalation and communication path.  

“Aligning on roles and responsibilities of us as consultants, and each of the clients’ stakeholder teams is key to defining a clear escalation and communication process to keep suppliers moving,” Leow explains. 

This structure should be paired with simple supplier asks by breaking work into milestones, sequencing steps, and using each touchpoint to clear specific hurdles. 

Quick wins, strategic shifts 

Early wins should be systematized, not sporadic. “Some basics, like regular audits for air or steam leaks, controls overrides, and equipment malfunctions, are essential,” Leow says. But he warns against getting stuck at “cheap and easy.” A key benefit of supply chain programs is their ability to push suppliers past low-cost measures. Strategic changes, such as electrification and renewables, require alignment across operations, procurement, facilities, and leadership. Engagement programs raise the pressure by communicating customer targets, and reduce the effort, by streamlining actions with clear resources. 

Renewable advantage 

For any firm, renewables strategy depends on context. Onsite viability hinges on basics like available space, local electricity prices, and regulations, while offsite options such as retail PPAs and VPPAs can scale across regions, and aggregation can multiply buying power. “Cohorts that aggregate load in RFPs improve economics and, importantly, raise interest from reputable developers — especially for smaller suppliers,” Leow says. 

Caution should be taken with over-purchasing renewables and allocating RECs to cover supplier electricity use. As of now, that approach generally doesn’t satisfy GHG Protocol and SBTi requirements for addressing scope 3. With nuances and potential updates ahead, any strategy should consider aligning with current rules. 

A dependable roadmap 

The following roadmap offers a pragmatic, four-point path from baseline and education to implementation and resilience, with clear ways to measure progress and maintain momentum. 

• Start by mapping and engaging your highest‑emitting, most strategic suppliers. 
• Define a simple maturity ladder with clear milestones and assess each supplier’s baseline against it.  
• Offer targeted actions and enablement that move suppliers one step at a time.  
• Run the loop on a fixed cadence: release offerings, track movement across milestones and verified reductions, escalate when progress stalls, and refine based on observed barriers.  

In the final analysis, a dependable roadmap for supply chain decarbonization is simple and repeatable: start fast, then get precise. Engage where impact and influence overlap. Build maturity with tailored support, and back it up with governance that maintains momentum. Before long, decarbonization will move from an aspiration to generating compound impacts across your supply chain. 

Take the next step: connect below with our team to assess your supply chain decarbonization readiness and identify your highest-impact next steps. 

Connect with us to learn more about supply chain program development: Trio Supplier Decarbonization Engagement Program