At London Climate Action Week, the session Supplier Engagement: What’s Worked, What Hasn’t — co-hosted by Exponential Roadmap Initiative, BT Group and We Don’t Have Time, in collaboration with the 1.5°C Supply Chain Leaders — highlighted both the complexity and the opportunity of supplier engagement in tackling Scope 3 emissions.

Moderator Nick Nuttall (We Don’t Have Time) opened the session with a clear message:

For many companies over 90% of their emissions lie beyond direct control; they’re embedded deeply within the supply chains and that’s why supplier engagement isn’t just important, it’s mission critical.

The panel featured representatives from Skanska, Exponential Roadmap Initiative, BT Group and AstraZeneca, who shared practical strategies that are already making an impact — and what still needs to happen to scale progress.

Who are the 1.5°C Supply Chain Leaders?

Louise Rehbinder, Director at Exponential Roadmap Initiative, introduced the 1.5°C Supply Chain Leaders, a coalition formed to enable collaborative supplier engagement and accelerate climate action across industries. Originally launched with BT Group, Unilever, Ericsson, IKEA, Telia Company and ERI, the initiative has since expanded and co-developed practical tools including the Supplier Engagement Guide and supported the SME Climate Hub.

A recent update shows that the majority of member companies are on track to meet their near-term climate targets — a promising sign of what is possible when companies act together.

BT Group: Embedding Climate into Contracts

When asked about approaches to supplier engagement that are already working at BT Group, Gabrielle Ginér, Head of Environmental Sustainability, highlighted two points to consider when talking to suppliers. Firstly, showing that you care about your sustainability goals and will continue to engage and even require suppliers to do too, and secondly training and upskilling individuals as an important part of collaboration. Ginér: 

We use education criteria [as an approach to supplier engagement], so when we award contracts sustainability can be up to 20% of that. We ask our suppliers to set science based targets, and to disclose them to CDP, but the lever that works really well is exercising our purchasing power [which] we do that through contracts. When we go into contract negotiation, we insert a sustainability clause, and that says to the supplier that over the term of the contract you are required to reduce your carbon emissions. We check on that on a quarterly basis.

AstraZeneca: SMEs and Early Engagement

Jen Valsler, Sustainable Director at AstraZeneca, stressed that all sectors and regions need to take action ultimately, not just the high emitters. An alternative priority system is therefore used within AstraZeneca, working with less mature businesses for which early engagement is key. SMEs are also prioritised; sustainability is often directly related to success for them, and can be essential for survival. Working with them is also crucial for diversity in the supply chain. Valsler: 

Sometimes the best good news stories that I hear are actually from those SMEs, which are really taking innovative action to progress even beyond [where] we are in some instances.

Skanska: Reframing supplier data

Nick Baker, Group Sustainable Supply Chain Manager at Skanska, described how the construction sector faces unique challenges — many suppliers aren’t in direct contact with the main contractor. To improve visibility, Skanska has started reframing emissions data to focus on individual suppliers, rather than materials, which has helped strengthen engagement.

With 80% of Skanska’s emissions coming from their supply chain, bridging this gap is critical to achieving climate targets.

Scaling impact through collaboration

Throughout the session, the importance of peer collaboration and shared standards emerged as a key theme. Both Valsler and Ginér shared how they engage in business associations to use the purchasing power of the industry as a whole rather than an individual company. Ginér described BT’s involvement in the Joint Alliance for CSR (JAC), a group of around 30 telecom companies aligning expectations on climate and circularity. Together, they’ve reached over 900 suppliers — and found that tailoring engagement to each supplier’s level of maturity makes collaboration more effective.

Final recommendations from the panel

To close the session, moderator Nick Nuttall asked each panelist to share one recommendation for companies looking to strengthen supplier engagement: