Impact Overview

GHG Emission of Plastics

GHG Emission of Transport

Final Impacts

Summary

All numbers in [gCO2e/kg Plastic]

Assuming x of Plastic Waste

Assuming that for Take-back programs an additional transport is necessary.

If we downcycle, we will only save carbon in best-case scenarios.

(3000 Virgin Plastic Production + 4500 Incineration)

We use a calcuation instead of the the "Plastic Overall" numbers to increase the range

Downcycling worst case + Small truck

Original Impact [gCO2e/kg plastic waste]*Amount Plastic Waste [kg] + Truck Impact [gCO2e]

We simply take the postive or negative impact and substract the truck impacts to simulate what would happen if take-back programs would reduce drive ways. That means we assume an entire truck load could be recycled & the recycling facility would be 5km closer than the incineration site

We assume incineration because landfills are unlikely to fully degrade plastics, although data on plastic degradation vary widely — nevertheless, microplastics would persist.

Explanation

"True" recycling can save significant amounts of carbon; however, long transportation distances can easily result in a net positive carbon impact—meaning additional CO₂e is released into the environment.

Virgin Plastic Production

(1500 Virgin Plastic Production + 700 Incineration)

Carbon Impact [g/km*t] * Kilometer [km] * Weight [t]

Downcycling best case + Small truck

Before starting a take-back program, try to ask your provider for some data. Most companies don’t share this information publicly, which makes it difficult to assess their sustainability.

Downcycling worst case:

(800 Mechanial Recycling Impact - 1500 Virgin Plastic Production )

We save on virgin production but have to account for the impacts of recycling — the end-of-life impact is assumed to be the same.

Even if you end up with a roughly neutral or slightly positive carbon footprint, it can still make sense to pursue a take-back program. Only by building these waste streams can we drive the broader establishment of recycling infrastructure—eventually making every take-back program truly sustainable.

(100 Incineration - 3000 Virgin Plastic Production)

Emission factors like gCO₂e per ton-kilometer are commonly used to estimate the environmental impact of freight transport. These numbers are typically based on average vehicle loads and average fuel consumption, which means they “blend in” the vehicle's empty weight to give a simplified picture of efficiency.

3x recycling worst case + Small truck

But this approach breaks down in edge cases — especially when trucks carry very little or no cargo. The problem is that in these low-load scenarios, the emissions from the vehicle itself remain, but there's almost no payload to divide them by. As a result, the gCO₂e/tkm value becomes extremely high or meaningless — and the average emission factors no longer reflect the real situation.

To understand the true impact in such cases, one can double-check the emissions based on fuel use per kilometer and calculate them directly using known diesel emission values (e.g., ~2.67 kg CO₂e per liter of diesel). These provide values in a similar range to those calculated using emission factors, but with lower variation in both directions.

(recycled: 1500 initial virgin generation + 800*2 Recycling Impact + 700 End of Life once) - (normal plastic: 2300 Liftime Impact*3)

We assume that we can truly recycle the same item x times - we thereby cut End-of-Life impacts in 1/x

In our example, we assume that take-back programs likely require longer transportation routes, as companies often have contracts with only a limited number of recycling facilities or must transport to their own recycling plants. If they simply use subcontractors, we can rather safely assume downcycling.

3x recycling best case + Small truck

For the calculation, we assume virgin production occurs x times, whereas in the recycling case, there is only one production, (x–1) recycling processes, and one end-of-life treatment

While average gCO₂e/tkm values are useful for general assessments, in our consideration of edge cases like near-empty transports, they must be reinterpreted. Since fuel-based emission estimates provide a similar — if less variable — result, using transport emission factors outside their intended scope is feasible but requires specific attention. Therefore, the final impact assessment here is not generalizable to a standardized unit (e.g., gCO₂/kg plastic waste) but refers to a single scenario.

(recycled: 3000 initial virgin generation + 100*2 Recycling Impact + 4500 End of Life once) - (normal plastic: 7500 Liftime Impact*3)

5x recycling worst case + Small truck

Mechanical Recycling

(recycled: 1500 initial virgin generation + 800*4 Recycling Impact + 700 End of Life once) - (normal plastic: 2300 Liftime Impact*5)

(recycled: 3000 initial virgin generation + 100*4 Recycling Impact + 4500 End of Life once) - (normal plastic: 7500 Liftime Impact*5)

5x recycling best case + Small truck

Lower incineration impacts are probably due to energy recovery (waste to energy).

Of course, it depends on the approach—e.g., the exact life cycle assessment boundaries—whether transportation is included in the final impact. However, if we assume equal distances to the recycling station and the incineration facility, we do not need to consider these impacts at this point.

3x recycling best case + Small Truck

5x recycling best case + Small truck

You can also calculate approximately 2–3 kg CO₂e per liter of diesel based on the average fuel consumption of a truck per 100 km. However, this approach is less variable than the one used above.

We only assume the best-case scenarios; otherwise, the impacts are in the range of incineration (more precisely, incineration with energy recovery).