Understanding Scope 3: Why Supplier Data Matters

By Dr Gee Nee Lim · Carbon accounting & Scope 3

Scope 3 emissions are often the largest part of an organisation’s footprint, yet also the hardest to measure. They sit outside your direct control, in the value chain, and depend heavily on the data your suppliers – and sometimes your customers – can provide.

What are Scope 3 emissions?

Under the GHG Protocol, Scope 3 emissions are indirect emissions that occur in your value chain. They are grouped into 15 categories, such as purchased goods and services, capital goods, waste, business travel and the use of sold products.

Why supplier data is so important

• Purchased goods and services can represent the majority of emissions for many organisations.
• Without supplier data you may rely entirely on generic emission factors and spend-based estimates.
• Improving data quality over time helps you understand which suppliers and materials drive most impact.

What to do when suppliers cannot provide data

In practice, many suppliers are not ready to provide primary data. A proportionate approach is to:

• Start with spend-based or activity-based estimates using recognised databases.
• Prioritise high-spend or high-impact suppliers for better data in future years.
• Provide simple templates and guidance to help suppliers share information.

Over time, the aim is to increase the share of Scope 3 emissions that are based on primary or semi-primary data, and to reduce the uncertainty associated with your value-chain estimates.

If you would like support in structuring your Scope 3 baseline or designing a supplier engagement plan, please see how we can support you.

Have questions? Contact me.

How to Start GRI Reporting (Beginner Friendly Guide)

By Dr Gee Nee Lim · ESG reporting & GRI

Many organisations want to align with the GRI Standards but are unsure where to start. The most effective approach is to treat your first GRI report as a structured learning exercise, rather than trying to be perfect on day one.

Step 1 – Clarify scope and reporting boundary

Decide which entities, locations and activities are included in the report. For example, you might begin with your UK operations only, or include selected subsidiaries where data is already available.

Step 2 – Run a simple materiality assessment

Identify which topics matter most to your stakeholders and to your organisation’s impact. This can be done with a light-touch process: interviews or workshops with key functions such as operations, HR, finance, procurement and senior leadership, combined with a review of peer reports and regulation.

Step 3 – Map data and evidence to relevant GRI disclosures

Once the priority topics are known, map existing data and policies against the GRI disclosures. Often, much of the information already exists in HR records, H&S systems, environmental data, or board papers – it just has not been assembled into one structure.

Step 4 – Close gaps and plan improvements

Highlight where there are gaps – for example, missing supplier information or incomplete emissions data – and be transparent about limitations in the first year. Then define a realistic improvement plan for future cycles.

A well-structured first GRI report focuses on clarity and honesty, rather than volume. Over time, your disclosures can become more detailed as your data systems mature.

If you need support designing a proportionate GRI roadmap or materiality process, please get in touch.

Have questions? Contact me.

PAS 2080 in Practice: What Delivery Teams Must Know

By Dr Gee Nee Lim · PAS 2080 & infrastructure decarbonisation

PAS 2080 is often seen as a “carbon standard for infrastructure owners”, but in practice it affects the entire value chain – from clients and designers through to contractors and product suppliers.

Governance and roles

A PAS 2080-aligned programme needs clear ownership of carbon across the project lifecycle. Typical roles include a senior sponsor, a carbon manager, and discipline leads who are accountable for identifying and delivering reduction opportunities in their area.

Whole life carbon and value-chain thinking

PAS 2080 emphasises whole life carbon – from materials and construction to operation, maintenance and end-of-life. Delivery teams are expected to consider carbon alongside cost, safety and programme when making design and procurement decisions.

Evidence, baselines and assurance trail

A key requirement is the ability to demonstrate how decisions were made. This means:

• Defining a clear baseline with documented assumptions and data sources.
• Recording options assessments and the carbon impact of chosen solutions.
• Keeping an audit trail that can be reviewed by clients, funders or external assurers.

What this means for day-to-day delivery teams

For engineers, designers and contractors, PAS 2080 does not require becoming carbon specialists. Instead, it asks them to:

• Flag carbon implications of design choices early.
• Engage suppliers on lower-carbon materials and methods.
• Use agreed tools and templates to capture data consistently.

When implemented well, PAS 2080 becomes part of normal project governance rather than an extra reporting burden.

If you would like help turning PAS 2080 into a practical carbon management plan for your programme, please get in touch.

Have questions? Contact me.

The Role of LCA in Identifying Carbon Hotspots

By Dr Gee Nee Lim · Life Cycle Assessment & Whole Life Carbon

Life Cycle Assessment (LCA) looks at environmental impact across the full life of an asset or product – from raw materials and manufacturing to use, maintenance and end-of-life. When used well, it helps teams pinpoint “carbon hotspots” where reductions will make the biggest difference.

From embodied carbon to whole life carbon

Many projects focus only on embodied carbon in materials. LCA expands this view to include operational energy, maintenance cycles, replacements and disposal, giving a more realistic picture of total impact over time.

How LCA identifies hotspots

By breaking the system into stages and components, LCA can show:

• Which materials or processes contribute most to total emissions.
• Where changes in design or specification could significantly reduce carbon.
• Trade-offs between options (e.g. higher embodied carbon but much lower energy use).

Using LCA results in decision-making

The real value of LCA is when results are fed back into design and procurement:

• Setting low-carbon design principles for future projects.
• Informing supplier requirements and product selection.
• Supporting business cases that combine cost, risk and carbon.

LCA does not have to be perfect to be useful. A screened or simplified LCA can still provide strong directional insight for teams making early-stage decisions.

If you would like support scoping an LCA or interpreting results for decision-makers, please get in touch.

Have questions? Contact me.

Building Reliable ESG Data: Common Pitfalls and Solutions

By Dr Gee Nee Lim · ESG data & reporting quality

ESG reporting is only as strong as the data behind it. Many organisations have good intentions but struggle with inconsistent spreadsheets, unclear ownership and weak evidence for reported numbers.

Typical data pitfalls

• No single “source of truth” – multiple spreadsheets with conflicting figures.
• Unclear definitions – different teams using different rules for the same KPI.
• Missing audit trail – no documentation of how numbers were calculated.

Foundations of a reliable ESG data model

A robust ESG data model usually includes:

• A simple data dictionary explaining each metric, units and boundaries.
• Named owners for key datasets (e.g. energy, HR, procurement).
• Standard templates for monthly or quarterly data collection.

Quality checks and review cycles

Basic validation rules – such as checking against last year’s figures or flagging extreme changes – can greatly improve reliability. Periodic internal review meetings help spot issues before numbers are shared externally.

Over time, these practices support more advanced reporting requirements such as CSRD, UK SRS or assurance by an external auditor.

If you need help designing an ESG data model or practical control checks, please get in touch.

Have questions? Contact me.

Designing KPIs for Sustainability and Carbon Performance

By Dr Gee Nee Lim · KPIs & performance management

Well-designed KPIs translate your sustainability strategy into day-to-day decisions. Poorly designed KPIs, on the other hand, can drive the wrong behaviour or become a reporting burden with little impact.

What makes a good sustainability KPI?

Effective KPIs are:

• Aligned with strategic priorities and stakeholder expectations.
• Measurable with data that is realistically available.
• Owned by a specific role or team, not “everyone and no-one”.
• Actionable – people understand what decisions the KPI should inform.

Example KPI areas

• Carbon: tCO₂e per unit of output, or % reduction versus baseline.
• Energy: kWh per m² or per product, plus share of renewables.
• Waste: % of waste diverted from landfill, or kg waste per unit.

Linking KPIs to governance and incentives

KPIs are most powerful when integrated into existing performance processes – management reviews, project gateways, supplier reviews and, where appropriate, incentive schemes for leadership.

Starting with a small, focused set of KPIs is usually more effective than trying to measure everything at once.

If you would like help designing a KPI set that fits your organisation’s maturity and data capability, please get in touch.

Have questions? Contact me.