Understanding Scope 3 Emissions for E-commerce

A practical guide to downstream transportation emissions and why they matter for online retailers.

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SustainabilityDec 8, 20248 min

If you've started looking into carbon accounting for your e-commerce business, you've probably encountered the term "Scope 3 emissions." It sounds technical, but understanding it is crucial for any online retailer serious about sustainability.

The Three Scopes Explained

The Greenhouse Gas Protocol divides emissions into three categories:

  • Scope 1: Direct emissions from sources you own or control (company vehicles, on-site fuel combustion)
  • Scope 2: Indirect emissions from purchased electricity, heating, and cooling
  • Scope 3: All other indirect emissions in your value chain—both upstream and downstream

Why Scope 3 Matters Most for E-commerce

For most e-commerce businesses, Scope 3 emissions dwarf Scopes 1 and 2 combined. If you're a typical online retailer without manufacturing facilities, your direct emissions might be minimal—maybe some office energy use and a company car or two.

But your Scope 3 emissions? They include:

  • Shipping products to customers (downstream transportation)
  • Manufacturing of products you sell (purchased goods)
  • Packaging materials
  • Returns and reverse logistics
  • Customer travel to pick-up points
  • End-of-life treatment of products

Downstream Transportation: The Low-Hanging Fruit

Of all Scope 3 categories, downstream transportation—shipping orders to customers—is often the easiest to measure and address. Here's why:

  • Data availability: You already have origin, destination, and weight data for every order
  • Established methodology: Emission factors for different transport modes are well-documented
  • Direct control: You choose carriers and can influence shipping options
  • Customer visibility: Shipping is tangible to customers in a way manufacturing isn't

How Shipping Emissions Are Calculated

The basic formula for shipping emissions is straightforward:

kgCO₂e = distance (km) × weight (kg) × emission factor

The complexity comes from determining the right emission factor. Different transport modes have vastly different carbon intensities:

  • Ocean freight: ~0.00002 kgCO₂/km/kg (most efficient)
  • Ground transport: ~0.00012 kgCO₂/km/kg
  • Air freight: ~0.0006 kgCO₂/km/kg (30x ground)

Taking Action on Scope 3

Once you're measuring shipping emissions, you can start reducing them:

  • Optimize warehouse locations to reduce average shipping distance
  • Offer ground shipping incentives to reduce air freight
  • Consolidate shipments where possible
  • Partner with carriers investing in fleet electrification
  • Offset remaining emissions through verified carbon projects

The key is to start measuring. You can't improve what you don't track, and Scope 3 downstream transportation is the perfect place to begin your e-commerce sustainability journey.