Packaging Carbon Footprint: Plastic, Paper, and Glass Compared

The Packaging Carbon Paradox

The conventional assumption is that paper and cardboard are always more sustainable than plastic. The lifecycle data tells a more complicated story. This guide explains the actual carbon footprint of common packaging materials, why the answer depends heavily on what happens at end of life, and how to include packaging in your Scope 3 Category 1 reporting.

Lifecycle Carbon of Common Packaging Materials

The carbon footprint of packaging should be assessed across its full lifecycle: raw material extraction and processing, manufacturing, transport, use phase, and end of life (recycling, incineration, landfill).

Production-stage emission intensities (DEFRA 2023 / Ecoinvent):

Why Paper Is Not Always Better Than Plastic

Corrugated cardboard boxes weigh significantly more per unit of protection than plastic films. A plastic protective film that weighs 10g may have a lower absolute carbon footprint than a 180g cardboard box providing equivalent protection — even at higher kgCO2e/kg intensity.

Key insight: Compare per-unit carbon footprint (total kgCO2e per 1,000 units of packaging), not per-kilogram intensity.

Additionally, paper recycling uses significant water and energy — the process is not impact-free. In regions where recycled cardboard mixes contain high contamination rates (common in municipal recycling streams), effective recycling rates may be lower than reported.

End-of-Life Scenarios and Carbon Impact

DEFRA 2023 Scope 3 Category 5 waste factors show the carbon difference between disposal routes:

The end-of-life route has a larger impact on total lifecycle carbon than the production material in many cases — which is why recyclability and actual local recycling infrastructure matter as much as material choice.

How to Include Packaging in Scope 3 Category 1

Packaging materials fall within Scope 3 Category 1 (purchased goods and services). To estimate emissions:

Spend-based method: - Total annual spend on packaging (£/€) × DEFRA spend-based emission factor for the relevant SIC category - DEFRA 2023 supplementary tables include factors for: paper and board packaging, plastic packaging, and glass packaging

Weight-based method: - Total weight purchased (kg) × production emission factor per kg (from supplier PCF data or Ecoinvent averages)

Example — small e-commerce retailer: - Annual cardboard box purchase: 3,200 kg virgin corrugated cardboard - Emission factor: 0.95 kgCO2e/kg - Category 1 packaging emissions: 3,200 × 0.95 = 3,040 kgCO2e = 3.0 tCO2e

Packaging Reduction Actions for Carbon Reporting

1. Right-size packaging — eliminate void fill by moving to box-on-demand or closer-fit carton sizing. Void fill in over-sized boxes increases total weight shipped per unit.
2. Switch to recycled content — moving from virgin to 70% recycled corrugated cardboard cuts production emissions approximately 45%.
3. Eliminate unnecessary secondary packaging — inner tissue paper, paper inserts, and branded tissue account for 15–25% of packaging weight in premium e-commerce.
4. Supplier PCF data — ask your packaging suppliers for a product carbon footprint certificate per material type. SMURFIT Kappa, DS Smith, and Mondi all provide PCF data on request.
5. Reusable packaging for B2B — returnable transit packaging (RTPs) used 20+ times typically has a per-trip carbon footprint 85–90% lower than single-use equivalents.