Air freight or sea freight?
When shipping long distance — from China to the UK for example — there are two main options: air freight and sea freight. Whilst they both serve the same purpose, the consequences of each are vastly different. Sea freight has a smaller carbon footprint than air freight. Air freight is quicker than sea freight. Sea freight is cheaper than air freight.
As a business wanting to make the best decision, you should weigh up all of the differences between air freight and sea freight. It's not enough to only focus on speed. Or environmental impact. If you do, you could risk missing the big picture, and that could be costly.
Let's dive deeper into three critical things to consider.
Air freight is bad for the environment
Different forms of transport produce different amounts of greenhouse gases. And between air freight and sea freight, the difference is staggering. We leveraged our life cycle assessment data* to compare the environmental impact of both for an example shipment travelling from China to the UK. It showed that using air freight would produce 31 times more emissions than sea freight.
For context, a freight train produces 1.6 times as many emissions as a cargo ship, and a truck 10 times as many. Put simply, sea freight has the smallest carbon footprint of all major forms of long-distance freight. Air has the largest.
What makes matters worse for air freight is altitude, where emissions have a more complicated impact. Carbon dioxide, for example, often has a more severe warming effect on the atmosphere at altitude than it does when emitted at ground level. Vapour trails too have their own warming effect, adding to the already harmful wake of air freight.
In other words, the environmental impact of air freight is more than the emissions a plane leaves behind. At altitude, the effects of those emissions are multiplied. So, whilst a straight comparison between air and sea CO2 emissions is telling enough, the true cost to the planet is likely to be much higher.
If you need to ship products across the world, and you want to reduce your business' carbon footprint, sea freight has to be a priority. That said, cargo ships still have a long journey ahead before they can be considered sustainable, but there are promising signs. In 2020, new worldwide fuel laws came into action, cutting the legal sulphur content in shipping fuels by 70%. Less sulphur means less air pollution, and that means less acid rain and cleaner air for the communities that live around ports. Together with new fuels on the horizon — such as biofuels and hydrogen — sea freight is heading in the right direction.
Sea freight is slow
For shipping, time might be important for three reasons. First, you want to pass on fast delivery times to your customers as value. Second, demand for your product fluctuates and you need the option of getting stock fast. Third, your product might need to be shipped quickly because of what it is. Perishables, for instance, will degrade over time, so it's important to first consider what it is you're shipping as this may define how you ship it.
In any case, if time is critical for your product, there isn't any competiton between air freight and sea freight. Air freight will always deliver much quicker than sea freight. Using our example shipment again, transporting it from China to the UK in a cargo ship could take 50 to 60 days. If you sent the same shipment on a plane, it would be with you in 3 to 5 days.
Sea freight also arrives at ports, and they're often further away from warehouses, offices and customers than airports. Shortening the distance between these logistical ingredients is one way to streamline your operations.
It's worth mentioning too that whilst both cargo ships and planes are affected by similar delays, such as extreme weather events, air freight is usually quicker to get back on track. Planes are often rerouted or rescheduled on the same day, whereas for cargo ships it can take days.
So, sea freight is much slower. But that doesn't mean it's a worse choice for your business, or that you can't meet the market demand for speed. If your product is suitable for sea freight, and you order stock in advance, long transit times may not impact your business as much as the numbers suggest. It just takes some planning.
Air freight is costly
Generally, air freight is much more expensive than sea freight. For the shipment we've been using, sending it via air would be 3 to 4 times more expensive than if you sent it via sea. Others estimate air freight as high as 6 times more expensive than sea freight.
The main reason for this is that planes are smaller than cargo ships, and because of that smaller capacity, space comes at a premium. There's just not the same opportunity to aggregate orders and benefit from shipping in bulk. For large shipments, this means sea freight is the cheapest option by far.
If you're shipping small quantities of lightweight items, the cost difference does shrink. That's because weight is a more dominant cost factor for air freight. And with a smaller margin, you might justify shipping air when balanced with other factors. But, even then, air is likely to be more expensive, and there should be a firm rationale behind choosing to pay such a price.
For long-distance shipping, sea freight is the most sustainable option — that's certain. It offers a chance to drastically reduce your product's carbon footprint whilst also cutting costs. Sea freight will take longer than air freight to get your product from A to B, but with smart planning, that extra time doesn't have to be a constraint.
As much as we prioritise shipping sea over air, this doesn't mean everything should be shipped that way. If your product demands it, air freight might be the only viable choice. Or you might be able to split shipments between air freight and sea freight. What is crucial, whichever you choose, is that you consider the big picture. Only then can you make an informed decision.
How Sourceful uses air freight and sea freight
To reduce the impact of everything we ship, we group orders together to optimise freight space. We always prioritise sea freight over air freight, and offset the CO2 emissions of all our shipments.
*This Life Cycle Analysis was based on a typical client shipment of e-commerce mailer boxes, travelling from China to the UK. The analysis includes the sea or air freight transit to the UK, as well as delivering the product from an airport or port to our warehouse in Manchester.
The analysis goes deep into each freight component, capturing the full impact of the shipment. This means we included all non-direct factors such as the construction of the aircraft, the maintenance of the container and the construction of the roads on which the truck travelled. The impact was modelled using our internal LCA technology and the freight datasets in Ecoinvent.
Source: Wernet, G., Bauer, C., Steubing, B., Reinhard, J., Moreno-Ruiz, E., and Weidema, B., 2016. The ecoinvent database version 3 (part I): overview and methodology. The International Journal of Life Cycle Assessment, [online] 21(9), pp.1218–1230. Available at: http://link.springer.com/10.1007/s11367-016-1087-8 [Accessed 01062021]
Other articles you might be interested in
Why the full life cycle matters
Data is the foundation of sustainability. It shows us the extent that our climate is changing. It’s the vital information that combats greenwashing, which nearly half of all green claims in the EU are guilty of . It’s the backbone of the IPCC’s (Intergovernmental Panel on Climate Change) reports (e.g. ). And it’s the foundation of every Life Cycle Assessment.
Life Cycle Assessments (LCA) are a powerful, science-based tool for estimating the potential environmental impact of products, processes, or services throughout their life cycle . For a full LCA, teams will typically look at data from five life cycle stages:
- Raw materials extraction
- Secondary packaging & transport
- Product use
- Final disposal
Missing one or more life cycle stages, however, directly affects the quality of the assessment. Leading organisations are on the same page. For example, The Competition and Markets Authority (CMA) , the Advertising Standards Authority (ASA)  in the UK and the European Commission for the EU all underline the need for high-quality data across the full life cycle to avoid making misleading environmental claims.
To quantify the impact of not assessing the full life cycle, we ran our own tests using our proprietary LCA engine. Here’s what we found: focusing only on a product’s raw ingredients can conceal between 25-70% of the product’s emissions. Put another way, selective reporting on a product’s emissions will never lead to accurate claims. The full life cycle matters.
Third parties: an extra layer of security
We’ve seen how LCAs rely heavily on the quality and completeness of data. But to ensure the highest standards of accuracy and consistency, third parties offer an extra layer of security. These include standards like ISO 14040 and 14044 and methodologies like the Product Environmental Footprint created by the European Commission.
A proprietary methodology
To go one step further, we developed our own LCA methodology. This allowed us to go beyond the static nature of a normal LCA and instead build an engine that could assess billions of product variants from different suppliers, giving results in real time whilst not compromising on accuracy. After building our engine, we commissioned an external panel of LCA experts and academics to review it to verify that our model conformed to the leading ISO standards.
It’s this rigorous homegrown approach that’s allowed us to develop a catalogue of science-backed products that in turn empower brands to make measurable progress. And it’s allowed us to support those brands in communicating that progress confidently with their customers.
What does the data say?
Our approach to LCA allows us to pinpoint both a product’s carbon hotspots and the biggest opportunities to reduce its carbon footprint.
We’ve found that the production of packaging components, international transport and disposal represent the majority of a packaging product's footprint. Let's dive deeper:
1. Production of packaging components
This stage, which includes the extraction, transport, and refinement of materials, typically accounts for the majority of the life cycle impact (for example, c.70% of our Eco Mailer Box’s total carbon footprint). An example of how we’ve reduced these emissions is custom sizing. By making custom sizing available for our packaging boxes, we’ve empowered brands to remove the empty and wasteful space that has become standard in the packaging industry. We estimate that this can reduce the total carbon footprint of a mailer box by around 8%.
Freight is carbon intensive, especially international air shipping which can represent up to 90% of the life cycle of packaging. But opting for sea freight instead can lower that number by 60%, which is the case with our recycled mailer bag. Whilst this is the best situation, we know that time is a significant constraint for brands, making sea freight often unfeasible.
We launched split delivery as a solution; a freight option where brands can choose how much of their order to send via air and sea. This allows brands to meet short-term demand whilst benefiting from sea freight’s significantly lower emissions. If a brand ordered 20,000 units and sent 10% by air freight, they could reduce their carbon footprint by up to 50% compared to sending the entire shipment via air.
3. End of life
End of life (also known as disposal) is an often overlooked but significant life cycle stage. Even for a cardboard box that can be easily recycled (71%, 2021 UK data, ), disposal still accounts for c.15% of its total carbon footprint. Disposal also varies dramatically between materials, making it a crucial part of any comparison. For example, whilst cardboard’s recycling rate in the UK is 71%, flexible plastic’s is unfortunately only 6% . This pushes disposal to account for c.21% of our recycled LDPE mailer bag’s emissions.
Always consider the full life cycle
For an accurate account of a product’s emissions, the full life cycle is essential. This is why authorities like the CMA and ASA require businesses to be clear on which stages of the life cycle they’ve included when making claims about a product’s environmental impact. Gold standard claims will always look at the full life cycle and selectively reporting on emissions will result in unreliable and dubious claims. This will put you at risk in a world that is demanding action and clarity.
With the full life cycle in hand, however, you can measure and track real progress, identify the best opportunities and communicate confidently with customers.
- Abnett, K. (2023). EU proposes clampdown on companies using fake ‘green’ claims. Reuters. Available here [https://www.reuters.com/business/sustainable-business/eu-proposes-clampdown-companies-using-fake-green-claims-2023-03-22/#:~:text=EU proposes clampdown on companies using fake 'green' claims,-By Kate Abnett&text=To use such labels%2C a,under an environmental labelling scheme]. (Accessed: 21 Aug. 2023).
- IPCC (2023). Climate Change 2023: Synthesis Report. doi: 10.59327/IPCC/AR6-9789291691647.
- PRé Sustainability (2020). Life Cycle Assessment (LCA) explained. Available here [https://pre-sustainability.com/articles/life-cycle-assessment-lca-basics/] (Accessed: 21 Aug. 2023).
- Competition & Markets Authority (2021). CMA guidance on environmental claims on goods and services. Available here [https://www.gov.uk/government/publications/green-claims-code-making-environmental-claims] (Accessed: 21 Aug. 2023).
- Committee of Advertising Practice (2021). The CAP Code. Available here [https://www.asa.org.uk/static/47eb51e7-028d-4509-ab3c0f4822c9a3c4/The-Cap-code.pdf] (Accessed: 21 Aug. 2023).
- DEFRA (2023). UK statistics on waste. Available here [https://www.gov.uk/government/statistics/uk-waste-data/uk-statistics-on-waste]
- WRAP (2021). Recycling your customers’ plastic bags and wrapping. Available here [https://wrap.org.uk/resources/guide/recycling-your-customers-plastic-bags-and-wrapping]
To achieve net zero and limit the worst of climate change, we have to rethink our reliance on plastic.
This statement is more urgent than ever, but the problem with plastics is unfortunately much bigger than just climate change. In reality, plastics also directly threaten human health and endanger habitats when leaked into the natural environment. Paradoxically, one of the main culprits of this damage is also claimed by some as the next green solution — compostable plastics.
To unpack this new material, we conducted a study on the environmental impact of compostable plastic bags, to find out if they truly offer a more sustainable alternative to traditional materials like paper, fossil plastics and recycled plastic. In this article, we’ll focus on one part of the study: the damage that leaked compostable plastics have on our ecosystems.
The consensus on compostable packaging is unclear
The biodegradable plastics market is projected to expand 2-3x between 2021 and 2026 . And at Sourceful, we’ve seen firsthand the escalating demand for compostable packaging. But whilst many brands are running towards compostable plastics, the consensus is still murky, with other companies (like Tesco and Abel & Cole) publicly distancing themselves from them. We wanted to use our research to help fill the vital knowledge gap and build consensus.
Compostable plastics are often considered a green alternative because they degrade and so are often (incorrectly) assumed to effectively disappear in the natural environment. The theory is that this reduces the amount of plastic in the ocean and the risk of microplastics. But as with most things — it’s not that simple. Life cycle assessments (LCAs) have historically struggled to account for leaked waste and microplastics because of a lack of data, even though both play a major part in a material’s overall environmental impact.
To tackle this, we partnered with the Sustainable Materials Innovation Hub at the University of Manchester. This gave us access to the latest labs, data on new and innovative materials and their in-house expertise — all invaluable to our study. Together, we investigated how traditional fossil fuels and compostable plastics behave when leaked. Here’s what we found.
The impact of leaked waste is twofold
One of the major environmental impacts of plastics (fossil and compostable), besides their carbon footprint, is their effect on the natural environment when leaked.
Leaked plastic waste generates both physical (e.g. animals ingesting microplastics or being entangled in larger pieces) and chemical risks (e.g. the leaching of toxic additives like plasticisers and flame retardants) to wildlife from the breakdown of plastic into microplastics and nano-plastics. Not only does the breakdown of plastics directly leach toxic elements but they can also act as a magnet for other environmentally harmful pollutants.
To make matters worse, leaked plastic waste has also been found to be directly connected to climate change. Researchers at the Ocean University of China found that microplastics reduced the growth of microalgae and the efficiency of photosynthesis, in turn degrading plankton’s ability to remove carbon dioxide from the atmosphere . The knock-on effect is that the ocean itself cannot capture carbon as efficiently; an essential resource in our fight against climate change, given that it sequesters 30-50% of total CO2 emissions from human activity.
Compostable plastics and leaked waste
The longer a plastic takes to break down, the more likely it will be ingested or cause entanglement. Put another way, the risk of adverse effects increases the longer a plastic persists. To account for this, we assessed each material for its degradation time in freshwater, marine, and soil environments, and used that data to identify a leaked waste impact rating for each material.
Our study found that whilst compostable plastics do reduce the risk of some adverse effects (less risk of entanglement and a shorter period of microplastics), they are not a cure-all for plastic pollution. Compostable plastics can persist in the natural environment for over half a century, which puts into question the popular claim that these plastics are the next green solution. This matches up with the conclusions that Narancic et al. made in their study . Here’s an overview of degradation times for fossil plastics and common compostable plastics:
- Fossil plastics take around 4-5,500 years to degrade in soil (with some studies suggesting this is even higher, at around 10,000 years); the worst and longest degradation time amongst all plastics. This is made worse by the common use of harmful additives .
- Compostable plastics like PLA take on average 1-63 years in soil to degrade completely. In water, PLA does not degrade at all.
- Other compostable plastics like TPS and PHB take on average 4-6 months to degrade completely.
So compostable plastics do have a tighter degradation window than fossil plastics, and they also typically contain fewer toxic additives (such as flame retardants and stabilisers). But they still can have a significant degradation window, especially and unfortunately PLA, one of the most common materials used in compostable packaging (including coffee lids and bags).
Admittedly, it is still hard to know the exact time it takes for a plastic to decay; the field of estimating polymer lifetimes is still relatively new. But we do have enough comparative data to give us an indicative hierarchy of materials that we can use to assess performance and inform decisions.
Compostable plastics do slightly reduce the risk of microplastics because of their shorter degradation times. But our larger study showed that compostable bags emit 1.5-2x more greenhouse gas emissions over their full life cycle than virgin fossil plastics. In addition, given they are still relatively new, there are uncertainties about the unintended consequences that could come from their use. ****This begs the question: are the reduced risks from leaked waste enough to offset the increase in carbon footprint? For now, we don’t think so.
What does this mean for my packaging?
It’s clear that we need to move away from fossil plastics. And in their current state, compostable plastics are not the next green solution. So, what’s the answer?
First, brands should follow the waste hierarchy. Can this packaging component be removed? Can we use less materials without compromising function? How can I design this product so it’s easy to recycle?
Second, brands should prioritise responsibly sourced paper if possible, which typically has the lowest impact of any material. Its full life cycle emissions are low, and there’s no risk of microplastics if leaked. That’s not to say it’s perfect; forests are often mismanaged and producing and recycling paper still generates emissions, uses large amounts of water and potentially also harmful chemicals. This is why certifications like the Forest Stewardship Council (FSC) and Programme for the Endorsement of Forest Certification (PEFC) are so important.
Paper isn’t also appropriate for every use-case and product, like liquids. This is why we stress prioritising paper if possible. Packaging should always be carefully matched with the product, and blanket rules rarely result in success.
For more information about this study, email firstname.lastname@example.org
Thanks to Dr. Guilhem de Hoe and Dr. Chloe Loveless from the University of Manchester for leading the collaboration.
Our study focused on the typical compostable plastics currently seen on the market (PLA, PBAT, PHA and TPS). Our study did not include a nascent group of materials classed as unmodified natural polymers, which we’re interested in exploring in the future.
- MarketsandMarkets. (2021). Biodegradable Plastics Market - Global Forecast to 2026.
- Zhang, C., Chen, X., Wang, J., & Tan, L. (2017). Toxic effects of microplastic on marine microalgae Skeletonema costatum: Interactions between microplastic and algae. Environmental Pollution, 220(B), 1282-1288. [Link] https://doi.org/10.1016/j.envpol.2016.11.005
- Narancic, T., Verstichel, S., Chaganti, S. R., Morales-Gamez, L., Kenny, S. T., De Wilde, B., Padamati, R. B., & O’Connor, K. E. (2018). Biodegradable Plastic Blends Create New Possibilities for End-of-Life Management of Plastics but They Are Not a Panacea for Plastic Pollution. Environmental Science & Technology, 52(18), 10441-10452. [Link] https://doi.org/10.1021/acs.est.8b02963
- Chamas, A., Moon, H., Zheng, J., Qiu, Y., Tabassum, T., Jang, J. H., Abu-Omar, M., Scott, S. L., & Suh, S. (2020). Degradation Rates of Plastics in the Environment. ACS Sustainable Chemistry & Engineering, 8(9), 3494-3511. [Link] https://doi.org/10.1021/acssuschemeng.9b06635
Right-sized packaging is the opposite of shipping small products in big boxes. It’s packaging that minimises the empty space around your product — whilst not comprising its safety or your branding. Or put another way, right-sized packaging is the most effective, and most efficient, size packaging for your product.
The benefits of right-sized packaging are many. As a business, you reduce your material usage, which means fewer costs across procurement and production. And smaller, lighter packaging also means fewer costs across transport and storage. All of this means a smaller carbon footprint, less waste and a better, less frustrating customer experience.
Whilst right-sized packaging seems a logical choice, businesses are notorious for using oversized packaging. According to DHL, the average box is 40% too big for its contents. In part, this is because businesses often buy large volumes of stock packaging to reduce unit costs. As a result, they have just a few packaging options for all their products. Products are then shipped in the nearest fitting packaging, regardless of their size. In practice, this means companies end up shipping the product and all of the air around it, which is expensive and wasteful. To put the scale of this waste into context, eliminating the 40% excess volume DHL cite would mean 24 million fewer truckloads annually — in the USA alone.
Another catalyst of oversized packaging is e-commerce. Unlike traditional retail, e-commerce is more complex and more people are involved across fulfilment, freight and last mile delivery — with up to four times as many touch-points. And with more touch-points, the risk of damage increases. According to one study, the average package is dropped 17 times in transit. Businesses use oversized packaging and void fill to minimise this risk and avoid breakage costs. Reducing breakage is important, but many companies don’t realise that with right-sized packaging they can both minimise risk and reduce costs, all whilst being more sustainable.
Let’s dive deeper into why your business needs right-sized packaging.
1. Slash costs across your business
Right-sized packaging is an ideal strategy to reduce costs for any business. In fact, choosing right-sized packaging can have a fortunate snowball effect across your business. Smaller packaging means fewer material costs, which then means fewer production costs and handling fees. And it means fewer transport costs as more packages can fit on a pallet. Or if you’re sending single products via a courier or Royal Mail, your package may fit into a cheaper parcel bracket. And finally, you can store more products for less, which also increases your buffer stock — a useful way to build a more resilient supply chain.
One famous example of right-sized packaging is IKEA’s Ektorp sofa. IKEA’s engineers worked out that instead of shipping the sofa as one piece, they could break it down and ship it as parts. This allowed them to eliminate the air they were shipping (and paying for) and reduce the packaging size by 50%. For IKEA, the result was an annual saving of €1.2 million and 7,477 fewer trucks on the road every year.
2. Reduce your carbon footprint
Whilst IKEA reduced their packaging costs, they also reduced their carbon footprint. Fewer materials meant fewer resources and less energy used to produce those materials. And it meant significantly fewer transport emissions as well as less waste. Although there are exceptions, the rule of thumb is when you use less, your carbon footprint falls, and right-sized packaging is an opportunity to use less. It’s important to remember that right-sized packaging is about removing redundant materials and keeping those that serve a purpose. This makes it a simple way to create more sustainable packaging without jeopardising your product.
3. Create frustration-free packaging and empower your customers
Consumers are tired of bad packaging, so much so that they’ve started Reddit threads to showcase the worst examples. Youtube too is full of consumers venting their anger about oversized packaging.
Their irritation is twofold. First, oversized packaging is often frustrating to open, with unnecessary materials creating a more complex, sometimes overwhelming experience. And second, oversized packaging is wasteful. At a time when research is showing that consumers want to be more sustainable, using excessive packaging hinders their efforts and doesn’t reflect their values. Right-sized packaging, however, addresses both parts of their annoyance. By keeping material usage down, it creates a frustration-free packaging experience and empowers your customers to play a part in reducing waste. A win-win for them and you.
Managing right-sized packaging is hard, but Sourceful can help
As great as right-sized packaging is, it isn’t perfect. Problems often arise because right-sized packaging is only right for one product, which means you may end up with a lot of packaging SKUs. Managing this can be tricky, but with the right tools, it doesn’t have to be. With Sourceful, you can use smart tools like Auto-Stock to manage, track and replenish your packaging in one place. You can also store everything in Sourceful’s warehouse. Fast-growing brands like Zoe and Floom already use Auto-Stock to easily manage their packaging, no matter how much they have. Want to learn more? Contact us.
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