Given the continuous growth in sales generated in Germany up until 2021 by e-commerce, this form of retail is expected to become increasingly important in the future. Although a slight decline in the volume of trade was observed in 2022, despite the current economic situation a fundamental long-term reversal of the growth trend is unlikely.
In view of this, a structured and comprehensive analysis of the environmental sustainability of e-commerce in Germany seems both expedient and appropriate. This study focuses on the environmental impact and a division into different areas of e-commerce, which are examined separately. The four areas, each of which was addressed as an independent work package, were:
- Delivery transport (including returns)
- Packaging (paper, plastic, reusable)
- Digital infrastructure (data centres, servers, energy requirements)
- Logistics centres (energy consumption and emissions of distribution and logistics centres)
In addition, two other current trends in German e-commerce were identified and investigated separately:
- New business models (instant delivery, recommerce platforms, retail-as-a-service)
- Sustainable consumption decisions in e-commerce
The most important findings with regard to each of these six aspects are briefly summarised in the following.
The delivery transport of an average B2C parcel by a CEP service provider currently causes 790 g of CO2e (this corresponds almost exactly to the emissions estimated for producing 1 kg of pasta or those emitted by driving a car for approximately 5 kilometres). Delivering a parcel from the sender to the customer causes approx. 866 g CO2e, whereas a return causes only 524 g CO2e, because returns are often transported by the customers themselves and there is therefore less delivery transport. For an average online purchase, the emissions from the delivery and the share of emissions from returns add up to 981 gCO2e (not taking into account any customer transport). Since most emissions are generated in the last mile, a parcel which is collected from a parcel pick-up point (without a prior delivery attempt) generates 442 gCO2e, which is significantly less than a parcel delivered to the front door, which generates 866 gCO2e. In total, approximately 1.7 million tCO2e are emitted for the transport of the 2.1 billion domestic B2C parcels. This corresponds to 3.7 % of road freight transport emissions. Of this parcel volume, 20% are returns, which are responsible for 13% of emissions. A total of 58% of the emissions are emitted on the final leg of the journey, the so-called last mile. At 20 ktCO2e, customer transport (e.g. to the parcel pick-up point) only accounts for a small share of the total emissions.
The growth of e-commerce is also accompanied by an increased volume of packaging. Cardboard makes up the largest share of packaging for shipping. Plastic packaging is now perceived as less sustainable. In general, the issue of sustainability is becoming increasingly relevant and approaches such as reusable packaging and other measures to reduce the environmental impact are gaining importance. Important aspects when weighing up the various packaging options include the volume of waste, recyclability, the proportion of recycled material, greenhouse gas emissions and, in the case of reusable packaging, the number of cycles. In Germany, disposable packaging made of paper or cardboard is generally recycled to a much greater extent and contains a higher proportion of recycled material than plastic packaging. Plastic packaging, on the other hand, generates less waste. Greenhouse gas emissions for disposable packaging range from 20 to 756 g CO2e, depending on the material used (paper/cardboard or plastic, proportion of recycled material) and the size of the packaging. For reusable packaging and assuming that return processing takes place at a central location within Germany, between 14 to 828 g CO2e of emissions are produced per cycle of use, this is dependent on the size, the proportion of recycled material and whether the packaging is flexible or rigid (i.e. foldable or non-foldable for return shipping). It is not possible to conduct a general evaluation comparing paper/cardboard packaging with plastic packaging; this requires a case-by-case assessment. However, plastic packaging can have lower CO2e emissions than paper/cardboard for smaller packaging sizes. The origin of the CO2 emissions must also be taken into account. When paper and cardboard packaging is finally disposed of (i.e. incinerated), biogenic CO2 is released. This means that this CO2 was previously taken out of the atmosphere as a result of the growth of the trees. In contrast, the disposal of plastic packaging currently releases fossil CO2, which is more problematic.
Determining the environmental footprint of the digital infrastructure of e-commerce is subject to many uncertainties and is dependent on individual consumer behaviour. When considering the emissions of a single online purchase, the influence of the consumer's behaviour (choice of energy-efficient end devices and sustainable use of the ICT infrastructure) can be identified and partially quantified. Thus, emissions of 63 g CO2e, resulting from the additional energy expenditure of a singular online ordering process, could be determined for the digital infrastructure of an average online order in Germany in 2020. However, this value can vary greatly depending on the assumptions made and the different usage scenarios.
A top-down analysis of the energy consumption of logistics centres revealed emissions of 66 g CO2e per parcel. The accuracy of this figure was verified using comparisons with the literature and the evaluation of various annual and sustainability reports of CEP service providers. In the bottom-up analysis, the values calculated were between 20-32 g CO2e per parcel and per logistics centre passed through. In general, however, such emissions can vary greatly depending on the logistics centres involved and related factors such as the size of the site (quantitative throughput, etc.), the work requirements and functions of the site (type of consignments, cold storage, hazardous goods, proportion of space for longer-term storage, etc.) as well as the technical equipment (e.g. degree of automation) and optimisation measures already implemented.
The three new business models examined (instant delivery, re-commerce and retail-as-a-service (RaaS)) differ from conventional e-commerce in only a few aspects and the impact of these differences on environmental sustainability is considered to be comparatively small. In the area of delivery transport, however, additional emissions can occur in all three business models examined: through the delivery to intermediate distribution centres and the low possibility of bundling deliveries in the case of instant delivery, through additional transport routes for reprocessing in the case of re-commerce (which, incidentally, would occur in exactly the same way in the case of a "right to repair") and through the combination of online and stationary trade in the case of RaaS, in which both customer traffic and delivery transport occur in the case of online trade. The electrification of transport again appears to be an important starting point for reducing the environmental impact. Especially the use of BEVs for the last mile can be one way to reduce emissions, e.g. for the prompt delivery of groceries ordered shortly beforehand, (provided it replaces the customers separate weekly shopping trip). In addition, the bundling of deliveries and the establishment of loading zones can have positive effects. Even if re-commerce does lead to increased delivery traffic, it can be assumed, in most cases, that GHG abatement through the lifetime extension of goods and the resulting avoidance of new production offsets any additional emissions. Meaning that the business models of re-commerce platforms (both C2C and B2C) can be seen as very positive for climate protection overall.
From a consumer psychology perspective, there are particularities in sustainable consumption decisions that arise from e-commerce. As a result, impulse buying can increase due to the high speed and ease of purchase. There are also heuristics that are of particular relevance to e-commerce and that can be used to promote sustainable purchasing decisions. Two heuristics of decision-making here are emotional stability ("avoidance of frustration purchases") and the need-satisfying effect of consumption ("identity creation"). The so-called attitude-behaviour gap explains why there is awareness of sustainability, but at the same time contradictory actions are taken. This correlation can be influenced by habits, which can also be suspended in the context of the purchase decision, as well as by social norms. These are some of the most powerful levers for changing purchasing behaviour.
An overarching view shows that most of the environmental impact generated by a product (e.g. resource consumption, emissions, etc.) does not occur during the trading process, but rather during the manufacturing or production process and any subsequent disposal (cf. Zimmermann et al. 2020; Collini et al 2022). The comparatively short trade segment is in most cases only responsible for a relatively small share of GHG emissions.
If customers choose to order online, which has been increasingly the case in recent years (IFH Cologne 2022), it becomes clear that online trade is responsible for a considerable range of different effects on environmental sustainability, but this must be seen in the context of the alternative to e-commerce, namely traditional, stationary retail, which also has an impact on the environment (e.g. in the form of GHG emissions and land consumption) (cf. Zimmermann et al. 2020; Collini et al 2022) and, in addition, here, too, customers travel a variety of distances (during purchase and possible return).
A real reduction in the harmful effects of trade could therefore only be achieved through greater consumer sufficiency, i.e. consciously refraining from consumption. Once the decision to consume has been made, however, or if consumption simply cannot be avoided, the choice between stationary retail or e-commerce must be made on the basis of environmental considerations, depending on the framework conditions of the individual case. Nevertheless, some specific starting points can be formulated for further improving the environmental sustainability of e-commerce.