Abstract
In the bid to stay competitive, online shopping platforms often offer a variety of shipping options to meet the preferences of consumers. While faster delivery might be desirable for consumers, this may be detrimental to the environment. Limited studies have evaluated the comparative environmental impact of different shipping options offered by e-commerce platforms. To fill this gap, this study aims to conduct a comparative carbon footprint assessment of the shipping options available in
Keywords
The e-commerce boom has brought significant changes to the global supply chain network, and online shopping platforms are constantly striving to improve their operations and provide higher quality service for their customers. To satisfy consumers’ desire for faster delivery services, these platforms (e.g.,
However, offering the consumer the choice to opt for faster and more convenient shipping alternatives may promote unsustainable consumption. In a study conducted by Dotcom Distribution, despite not having an immediate need for the items, 47% of online shoppers were willing to pay more for the sake of receiving their items sooner (
This research therefore aims to examine the following research questions: (1) What is the estimated carbon footprint of various cross-border e-commerce shipping options? (2) Will carbon labelling have an influence over consumers’ cross-border shipping preferences? For this purpose, the relative carbon emissions of shipping options on
Since consumers who are interested in sustainability have been found to be strongly influenced by the labelling of sustainability information in products, the hypothesis is that, apart from informing consumers of the delivery time and the shipping cost, it can be environmentally beneficial if consumers are also informed of the carbon impact of different shipping options to aid in their decision-making process (
The remainder of this paper is organized as follows: The next section reviews the relevant literature. In the following section the carbon footprints of cross-border shipping options are assessed. Finally, the impact of carbon labelling on consumers’ shipping preferences is examined.
Literature Review and Approach
The emergence of digital payment methods and e-commerce platforms or marketplaces provide consumers with the means to purchase from both local and international sellers. This has accelerated the development of both domestic and cross-border delivery operations worldwide. “Domestic deliveries” or “domestic shipping” refer to the delivery of the items sourced from within the country’s border. This differs from “cross-border deliveries,” which refers to the delivery of items imported from other countries and jurisdictions. Cross-border operations are often deemed to be more complicated and less efficient as compared with their domestic counterparts (
There are currently few studies on the comparative environmental impacts of different shipping options offered by e-commerce platforms. The existing literature has focused on the carbon implications of short-haul domestic deliveries and has mainly sought to identify more sustainable alternatives that can reduce the impact on the environment (
However, as compared with the scrutiny when examining the environmental implications of common consumer products, there has not been as much attention given to the shipping options offered on e-commerce platforms. Even if consumers were to be provided with additional information about the carbon footprint of shipping alternatives, it remains uncertain whether this will be considered. Shipping cost and delivery speed may still take precedence in their decision-making. This led to the question about the value and attention paid toward labelling of carbon information on shipping options. Brunetti et al. conducted a survey on the perception of e-commerce and its impact on the environment (
To study consumer preference, stated preference surveys or SC experiments are regularly applied across various disciplines and, among which, transportation is one of the fields with the most established research on choice analysis (
Nguyen et al. found that consumers’ preferences are predominantly driven by the
Previous studies have found that
Several studies have gathered that
Apart from cost, speed, and order value, other potential delivery attributes that were considered in previous studies include the availability of order tracking services, the ability to choose a carrier (logistics provider), delivery date, and delivery time slot (
Case Study
The first objective is to conduct a comparative assessment of the different e-commerce shipping options for cross-border purchases, evaluating their carbon footprint, delivery time, and shipping cost. This assessment will focus primarily on the carbon impact created by the consumers as a result of their shipping decisions. The online shopping platform,
Shipping the parcel from China to the destination country via air or sea freight mode
After the parcel reaches the destination country: delivering the parcel directly to the receiver’s address—for example, home address (home)—or to a collection point (CP). (A CP is a pre-arranged destination that the consumer can opt for to temporarily store their items before collection.)
If multiple orders from different sellers are made in the same transaction, whether the consumer would want the orders to be consolidated into a single parcel before being shipped to the destination country, or not. (If a customer chooses to ship their items via sea freight, the option to ship the items to a CP is not available.)
With these different options available to consumers, the onus is on them to make informed choices at the point of purchase. This case study into
Carbon Footprint Assessment
Methodology
In a multiple-order transaction, the logistics process required to fulfill the online orders is broken down into different stages to facilitate the assessment of the carbon footprint, cost, and delivery time for each shipping option (see Figure 1). The study scope will include the following stages:

Cross-border logistics process for each shipping option.
For freight transport segments of the logistics process (stages A, B, D), the carbon footprint in relation to carbon dioxide-equivalent emissions (kg CO2e) will be estimated in accordance with the activity-based approach proposed in the ECTA guidelines (
The supplier locations are randomly selected from a list of 24 Chinese cities which have been demarcated as the New Cross-Border E-Commerce Zones (Figure 2) (
Carbon Emission Factors for Various Transport Modes

Map showing Singapore and Guangzhou, the main departure city from China, and assumed supplier locations in China as grey dots.
For the last-mile delivery to a consumer’s home or CP (stages D and E), conventional diesel delivery vans are assumed to be used for transporting parcels from the warehouses to their destinations. This research utilizes the carbon audit approach employed by Edward et al., where carbon emissions for last-mile deliveries are calculated on a per drop basis (
The carbon emissions for warehouse operations (stage C) is also considered in this study. Since the size of e-commerce parcels is mostly small, it is assumed that the parcel will not exceed the dimensions of 42 x 37 x 61 cm, which is the size restriction for a parcel to be delivered to a CP in Singapore (
Shipping costs are estimated based on
Results
The impact of different shipping options was compared for various scenarios of online orders placed (Table 2). Scenarios include the placement of single (one) and multiple (two) orders, which represent the average number of e-commerce orders observed in Asia per shopper, with the possibility of the latter being consolidated (
Scenarios of Shipping-Related Options Selected on
According to International Post Corporation (IPC) research on cross-border e-commerce deliveries, 63% of the cross-border parcels were found to weigh between 0.2 kg and 2 kg (
The “sea-home” shipment option is found to be the least carbon-intensive option for a single-order scenario, while the “sea-consolidated-home” shipment option is the least impactful option for a multiple-order scenario. The associated carbon emissions are estimated to be 0.67 kg CO2e and 1.19 kg CO2e, respectively. In general, shipment consolidation, slower freight transport mode (sea versus air), and cleaner passenger transport mode (walk versus car) can reduce emissions. From the carbon footprint breakdown in Figure 3 (stages A–E), it is observed that carbon emissions are most sensitive to the choice of sea or air shipment for cross-border transport (stage B). The emissions generated from shipment via air are found to be 65 times greater than the emissions from sea shipping.

Carbon footprint compared for different shipment options for the two-order scenario.
By comparing the delivery time with the associated carbon footprint, it can be established that the least carbon-intensive shipping option is both the slowest and the cheapest option. If consumers do not have an immediate need for the items purchased, they can reduce carbon emissions associated with the delivery by at least 81% by opting for sea instead of air freight. This switch would entail an additional waiting time of around +5 days (50% increase in waiting time).
Examining the carbon footprint breakdown for last-mile delivery (stages D and E), it is found that the overall emissions generated for home delivery are greater than delivery to a CP by only 0.012 kg CO2e (Figure 4). This small difference is a result of the low first-attempt delivery failure rate. The emissions sustained for traveling by bus to the CP was also found to be negligible (0.016 kg CO2e) because of the low public bus emission factor estimated for Singapore.

Carbon emissions associated with last-mile delivery per parcel.
Shipping Choice Experiment
Methodology
The previous section has revealed the relative carbon emissions of alternative shipping options on a popular e-commerce platform for cross-border purchases in a region experiencing dramatic growth in the Internet economy. If such information is made more readily available, consumers can potentially make more-informed choices, and consider the environmental implications more carefully. To validate this hypothesis, a shipping choice survey is conducted to investigate consumers’ willingness to wait for their orders, as well as consumers’ willingness to pay more for a less carbon-intensive option. The choice experiment will examine how consumers would trade-off shipping cost and additional waiting time if they were provided with additional information about associated emissions.
The shipping options from
Full Factorial Design of the Scenarios
The experimental design is important as it affects whether the respondents can wholeheartedly participate as if they were the one purchasing the item in the scenario. Apart from using realistic attribute values, the survey questions should also be presented to the consumers in a simple and intuitive manner. To ensure that respondents are not overwhelmed by the amount of information, the shipping alternatives were introduced in sets of two. Furthermore, to enhance the realism of the survey, symbols and colors were used in the design of the choice options to mimic the interface of an e-commerce check-out page (see examples in Figure 5).

Choice options for: (
Results
The online survey was carried out in Singapore over the period of June to July 2020. Adult Singapore residents with prior experience of making cross-border Internet purchases were recruited. There was a total of 220 completed questionnaires and, after filtering away irrational responses, 188 valid responses remain. The demographic and online purchasing profile of respondents are shown in Figure 6. This sample does not deviate greatly from the known profile of online shoppers in Singapore. In 2019,
Picodi.com
reported that more women (57%) shopped online than men (43%) (

Profile of survey respondents (
Table 4 below represents all the possible options and the number of respondents who have opted for these options in each of the three contexts. For instance, in the context where the slower shipping option is cheaper, 120 of 188 respondents (64%) preferred lower shipping cost over faster delivery for a high-value order. This observed behavior is denoted by “type P.” Based on the indicated choices, their preferential rankings with regard to the cost, speed, and carbon factors can be determined.
Summary of the Options Selected by Survey Respondents
Since shipping cost was found to be the dominant decision factor, the respondents are expected to opt for the cheaper alternative in the context where price differentiation exists. Based on the survey results, there is indeed a high proportion of people with behavior types “P” and “U.” The discussion and analysis of the choice selection for each of the three contexts is further elaborated below:
In the context where the slower option is cheaper, it is observed that there is a smaller proportion of respondents with behavior type “P” in the high-value order scenario (64%) than the low-value order scenario (90%). This signifies that more people will opt for the faster option if the order value is higher. Out of those who have initially opted for the faster option, 56% of them switched to the slower option for their high-value purchases after being informed of the carbon footprint, while only 31% switched in the low-value order scenario. This indicates that the people who favor the faster option for low-value purchases are unlikely to be influenced by information about the carbon implications.
Even though the proportion of respondents who displayed behavior type “U” is smaller for the high-value order scenario (83%) than the low-value order scenario (89%), the difference is marginal, indicating that most people are unwilling to pay for greener shipping no matter the value of their purchases. The respondents in this survey have shown a higher willingness to pay for faster shipping than for greener shipping.
For the case where there is no price differentiation, 40% of the respondents have opted for faster shipping (behavior type “B”) despite not having an immediate need for the items. The willingness to wait for greener shipping is slightly lower for high-value orders, which is expected, since it has been established that there are some people who only value speed for higher-value orders.
The consumers could thus be segmented according to their purchase behavior. There can be up to 12 (3 x 2 x 2) different consumer archetypes for each order value level. For instance, consumers with the overlapping set PWA are those who will opt for the greenest option regardless of the trade-off between the shipping cost and the delivery timing. The factors that influence their shipping choices are thus ranked in the following order: carbon > speed > cost. On the other hand, consumers who belong to the archetypes CUA, CUB, CWB, PWB, and TUA are classified to have no strict preferences, since their indicated choices are inconsistent. To put it simply, these respondents have indicated that A > B, B > C, and C > A. Table 5 summarizes the number of respondents that belong to each consumer archetype for the high-value order and low-value order scenarios, respectively. The zero overlapping sets are excluded from this table.
Summary of Discovered Consumer Archetypes and Number of Respondents (Percentage of Respondents in Brackets)
Despite the small sample size, findings in Table 5 provide initial insight into the general distribution of the top and minority consumer archetypes. The proportion of respondents with the archetype PUA (41%) is surprisingly larger than the respondents with archetype PUB (26%) and TUB (11%). PUA refers to those who are willing to wait for greener shipping provided that the greener option is also the cheapest option; PUB and TUB refer to those who disregard carbon labelling and rely only on shipping cost and delivery speed in their decision-making. The preference for greener shipping is similarly reflected in respondents with the overlapping set PWA, which is also the fourth-largest archetype (10%). By combining the statistics for consumers with archetype PUA, PWA, and CWA, a significant fraction (55%) of respondents is found to be willing to compromise the speed of delivery for the greener alternative.
The portrayal of such high willingness to wait for greener shipping could be because half of the survey sample is composed of a younger demographic (age 18–25 years) who may tend to be more environmentally conscious. Based on these results, there is evidence that the presence of carbon labelling can potentially influence the choice of e-commerce shipping options.
Conclusion
Global trade interconnectedness provides consumers with greater accessibility to products worldwide and this has perpetuated the growth of cross-border e-commerce. To achieve their revenue-maximizing objectives, most online shopping platforms offer differentiated shipping options to cater to consumers’ unique preferences. As a result of the increasingly competitive e-commerce market, consumers may be presented with alternative shipping options. Since emissions vary considerably for different options, consumers may remain unaware of the relative impacts and unwittingly opt for less-sustainable outcomes. This situation could be avoided if consumers can make more informed choices. This study provides a novel assessment of the carbon footprint of cross-border e-commerce shipping options. The results from the assessment were then utilized in a shipping choice experiment to examine the impact of carbon labelling on consumers’ shipping decisions.
With regard to the carbon footprint assessment, it was observed that carbon emissions for cross-border e-commerce orders placed on
From the shipping choice experiment, more than half (55%) of the respondents were found to be willing to wait for greener shipping if carbon labelling was presented. While the sample size is small, the results suggest interest in carbon labels on e-commerce platforms, which have the potential to influence online shopping decisions. Therefore, this study advocates for consumers to be informed of the carbon footprint implications at the point of purchase on the e-commerce platform. Future research can look into scaling up the survey efforts and better understanding demographic and socioeconomic characteristics that influence online shopping behaviors and underlying preferences.
While the case study presented looks into the options offered for cross-border deliveries to Singapore, the framework of analysis is a general approach that could be applied to online shopping platforms in any region. This is applicable so long as the supply chain operations can be determined to facilitate the allocation of carbon footprint across each stage of the supply chain, including consideration of other cross-border transport modes like truck or rail.
This study gathered interest from the consumers’ perspective toward sustainable e-commerce, which provides basis for further research. Beyond the environmental impact and demand-side reception, it would be important to consider the economic impact of lower-carbon shipping initiatives. For instance, with greater willingness to delay shipments, this permits opportunities for freight consolidation and delivery route optimization. However, in reducing the frequency of carbon-intensive delivery trips, this may result in higher storage cost and slower-moving inventory. Carbon labelling could also influence the freight transport demand, thereby affecting overall logistic cost and operations. Further supply-side analysis will be required to develop a more comprehensive understanding of the trade-off between environmental impacts and economic viability, ultimately to achieve more sustainable freight and consumption.
Footnotes
Acknowledgements
The authors thank an anonymous carrier in Singapore for sharing data and insights on e-commerce parcel deliveries.
Author Contributions
The authors confirm contribution to the paper as follows: study conception and design: L. Cheah; data collection: L. Cheah; Q. Huang; analysis and interpretation of results: L. Cheah; Q. Huang; draft manuscript preparation: L. Cheah; Q. Huang. All authors reviewed the results and approved the final version of the manuscript.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.

