Plastic vs Cardboard Packaging: A Complex Choice

The world would be much better off if we replaced all of our plastic packaging with cardboard – wouldn’t it? The plastic vs cardboard packaging debate is more complex than you would think.

We recently highlighted the key issues in the debate between Plastic vs Compostable Packaging which is a complex enough and generated some solid discussion. Plastic vs Cardboard takes this complexity a step further!

Cardboard comes from trees that can be replanted, it’s easy to recycle, and it naturally decomposes. Plastic, on the other hand, is made from oil, it’s hard to recycle, and it never, ever breaks down. But when we compare plastic vs cardboard packaging head-to-head – some of the results might surprise you.

To help us make an educated choice between the two, we need to understand their impact on natural resources, the energy and water required for production and recycling – and the long-term environmental impacts.

So, let’s take a deeper look and find some answers.

Where It All Begins: The Raw Materials

To accurately compare plastic vs cardboard packaging, we need to understand more about how we source the raw materials that go into them – and what effect this has on the environment.

Plastic is made directly from fossil fuels, which generally takes the form of crude oil, and sometimes natural gas. Currently, plastic manufacturing consumes around 12% of the global oil supply – but this figure is expected to skyrocket to almost 50% by the year 2050. While the emergence of electric vehicles is beginning to reduce the need for petrol and diesel, our addiction to plastics looks like it will sustain the demand for crude oil.

Most plastic eCommerce packaging – like envelopes, protective coverings, and bubble wrap – is made from polyethylene, the most common plastic in the world. To make this material, oil or gas undergoes a series of industrial heating, cooling, chemical treatments, and moulding before eventually reaching its final form. And although making plastic seems like an expensive and complicated process, the scale of manufacturing produces tremendous volumes of low-cost material.

In the EU, around 90% of plastic is made from virgin fossil fuels, while only 9% is made from recycled materials.

Cardboard is made from paper, which comes directly from trees. While trees can re-grow and are therefore ‘renewable’ – it also depends on whether they’re sourced via deforestation or from sustainable wood that is grown specifically for manufacturing.

To make paper, trees are cut down and turned into wood chips, which are then either boiled in water or mixed with chemicals to create pulp. This pulp is then spread out and pressed on large flat screens that remove the water and produce paper. To turn this into cardboard, two flat layers of paper are glued on either side of a corrugated sheet to create additional strength. One fully-grown tree can produce enough paper to create around 150 large cardboard boxes.

Globally, around 55% of all cardboard is still made by cutting down trees, but the majority of logging is now performed in a controlled, renewable way. The Forest Stewardship Council  and the Program for the Endorsement of Forest Certification are two international organisations that certify sustainable forests – helping retailers and consumers to identify paper goods made to strict environmental standards.

In summary, both plastic vs cardboard packaging rely on natural resources, although trees are renewable while oil is not.

The paper industry is one of the more sustainable in the world, with a growing emphasis on responsible logging, waste reduction, and tree replanting.

Plastic, on the other hand, is still made primarily crude oil and natural gas, which is not only bad for the environment – it accelerates the depletion of a non-renewable resource.

The Carbon Footprint of Manufacturing

We also need to consider the carbon emissions created during the production of cardboard and plastic packaging. And this includes not just the manufacturing itself – but the greenhouse gasses released when sourcing raw materials and the emissions created when disposing of the end products.

The creation of plastic accounts for 3.8% of global greenhouse gas emissions – almost double that of the entire aviation industry. If plastic manufacturing were a country, it would be the 5^th largest greenhouse gas emitter in the world.

Paper and cardboard products also require a significant amount of energy to source and produce. However, the global carbon footprint of the industry is relatively low – only around 1% – due to manufacturers using renewable energy sources such as biomass, biogas, and hydroelectricity. In many cases, paper and cardboard factories use their waste products as a source of fuel.

The cardboard federation of France estimates that 1 ton of cardboard produces 538kg of CO2 during its lifecycle, which takes into account sourcing materials, transport, manufacturing, and disposal.

Plastic is made via a more efficient process that requires around 40% less energy than cardboard while also producing less waste. On face value, plastic vs cardboard packaging appears to have a lower carbon footprint – but we also need to look at what happens before and after the plastic is made.

Plastic comes primarily from crude oil, which carries a significant carbon footprint due to its extraction, refinement, and transportation demands. In addition, the majority of plastic is not recycled and ends up in landfill or waterways, or in many cases – industrial incinerators.

“Westminster council sent 82% of all household waste – including that put in recycling bins – for incineration in 2017/18.”

Source: The Guardian Newspaper

Some discarded plastic is used in ‘waste to heat’ plants that turn it into a source of fuel, but a high percentage of plastic waste is simply incinerated and released into the atmosphere as a toxic gas.

With all of this factored in, plastic can actually have a CO2 footprint as high as 6kg for every 1kg of plastic created – around 12 times higher than cardboard.

In summary, plastic is actually more efficient to manufacture than cardboard and produces less waste during the process. However, much of plastic’s carbon footprint comes from the extraction and transport of raw materials – namely oil and gas – and it produces significantly higher emissions when incinerated – which is common.

Cardboard manufacturing uses a high percentage of recycled materials, and the process is often powered via renewable energy. Combine these factors with a high end-of-use recycling rate, and cardboard maintains a substantially lower carbon footprint.

Plastic vs Cardboard Packaging: Weight and Its Impact on Transport

When we compare the eco-credentials of different retail packaging, one factor we rarely talk about is weight – and the impact this has on transport and fuel emissions.

Plastic is popular not only because it’s strong, flexible, and cheap to make – it’s also very lightweight. By contrast, cardboard is considerably heavier and bulkier – presenting challenges when it comes to transport and storage.

If you’re an eCommerce store that sells clothing, for example, you may have a choice between shipping items in small corrugated boxes or thin plastic mailers.

In terms of weight, a small cardboard box can weigh 80 – 100 grams – whereas the equivalent plastic mailer can weigh as little as two grams. For packaging distributors, this means that 10,000 cardboard boxes can weigh up to 1,000kg, but the same number of plastic mailers can be as light as 20kg.

This weight difference has a large bearing on transport costs and fuel consumption, and ultimately – CO2 emissions.

“Reducing the weight and thickness of packaging is the best way to both minimise impact on the environment and keep costs down.”

Source: Carlsberg Group Sustainability Report

In summary, in the plastic vs cardboard packaging debate, plastic has a clear advantage over cardboard when it comes to transport, due to its incredibly low weight-to-strength ratio.

With the rise of electric vehicles, this will help to reduce the CO2 emissions of transport across the board, particularly when shipping heavy paper and cardboard products.

The key takeaway for eCommerce companies is that whether using cardboard or plastic, reducing the thickness and weight of packaging plays a vital role in reducing greenhouse gas emissions.

The Benefits of Recycling: More Than Meets the Eye

We all know that recycling is inherently good, and it reduces the demand for limited natural resources by reusing existing materials.

But there are other advantages to recycling that aren’t as obvious – such as the significant savings of energy and water.

Paper and cardboard recycling has been commonplace for decades, and many consumers have come to expect packaging to be made from a high percentage of recycled materials – if not completely.

Recycling 1 ton of cardboard requires around 25% less energy than making it from new materials, and up to 50% less water.

Plastic recycling is even more beneficial, with 1 ton of plastic requiring 65% to 88% less energy than making it from new materials. Exact figures about water consumption are scarce, although a significant amount of water is used to clean plastics in preparation for recycling, and then also used as a coolant during the recycling process. Some companies have created plastic recycling methods that don’t use any water – although they don’t appear to have been adopted in the mainstream.

In Australia – a country with relatively high recycling rates – almost three-quarters of paper and cardboard waste is recycled – but less than a third of plastic. The remaining two-thirds ends up in landfill and waterways, is shipped overseas, or is incinerated.

Of all the plastic ever created, 91% has not been recycled.

Source – National Geographic

Producing new products from recycled feedstock is more energy efficient because it eliminates many of the steps required to source and prepare the raw materials – particularly in plastics. With the benefits of plastic recycling becoming more apparent, it’s little wonder there’s a growing industry of companies sourcing ocean plastics and turning them back into raw materials for manufacturers.

In summary, recycling both paper and plastic has significant benefits to the environment, not just in reducing the demand for new trees and crude oil, but in reducing energy and water consumption during manufacturing.

Plastic recycling is especially beneficial to the environment, as the reuse of plastic waste removes it from landfills and waterways while also reducing the demand for oil and gas.

What Happens When We Throw It Away?

While the recycling rates of solid waste have been gradually increasing, a lot of the items we use and discard every day end up somewhere we might not expect – in an incinerator.

In the EU, for example, here are the breakdowns for the disposal of plastic vs cardboard waste:

Plastic: 40% is recycled, 30% is sent to landfill, and 30% is incinerated.

Cardboard: 86% is recycled, 10% is sent to landfill, and 7% is incinerated.

Cardboard decomposes much faster than plastic, and can completely break down in around two months under the right conditions. Plastic, by contrast, is estimated to last between 400-1000 years. The reason this is only an estimate is because the mass-production of plastic only started in the 1960s – we don’t know how long the waste materials will actually last.

Even though cardboard decomposes quickly, it releases methane into the atmosphere, which is one of the most prominent greenhouse gasses. Plastic breaks down at a rate so slow it’s barely measurable – so it’s gas release is virtually non-existent.

In summary, cardboard has a clear advantage over plastic when it comes to breaking down, although it does release greenhouse gasses in the process.

Plastic takes up to 1000 years or more to decompose – which is a massive problem – but the silver lining is that its solid form prevents more greenhouse gasses from entering the atmosphere.

Ultimately, the only solution is to recycle as much waste as possible – especially when it comes to plastics.

Cardboard vs Plastic Packaging Compared Head-to-Head

To make a useful final comparison between the two, let’s take a look at some of the key stats associated with creating 1kg of each material. These figures take into account not just the manufacturing process, but also the sourcing of raw materials.

1kg of new cardboard requires approximately:

• 3kg of wood
  • 350 litres of water
  • Between 7 and 14 kWh of electricity

When using recycled materials, water consumption can be reduced by 50%, and energy use by 25%.

In landfill, cardboard takes between 2 and 12 months to decompose.

1kg of new plastic requires approximately:

• 2kg of petroleum
  • 180 litres of water.
  • Between 17 and 32kWh of electricity

When using recycled materials, energy consumption can be reduced by up to 88%.

In landfill, plastic takes between 400 and 1000 years to decompose.

When it comes to transport, plastic has a much lower carbon footprint than paper and cardboard due to its smaller volume and weight. For eCommerce, plastic packaging can be up to 20 times lighter than the equivalent items made from cardboard.

In Conclusion – Plastic vs Cardboard Packaging, which should you use?

When we take everything into account, cardboard is preferable to plastic in most categories – but the difference isn’t always as big as people might think.

Although cardboard requires less energy to produce, it also uses more water and creates more solid waste in the process. Cardboard is also bulkier and heavier, meaning there are higher CO2 emissions associated with transport.

But cardboard is also made from a sustainable source, is more commonly manufactured with renewable energy, and is much easier to recycle at the end of its usable life.

The fact that plastic is still made primarily from oil is a giant red flag for many people, and it’s clear that our current method of creating and using plastic is unsustainable.

Although plastic recycling is starting to gain momentum, we still recycle cardboard at least three times more often, and new cardboard products are far more likely to be made with recycled feedstock.

“While recycling is great in a lot of ways, the ultimate goal is to get people to prevent waste in the first place.”

McKenzie Jones, Arizona Daily Sun

Perhaps the key takeaway from all of this is that regardless of whether we use cardboard or plastic – we need to reduce materials, reuse packaging, and recycle far more waste than we do today.

Although the term ‘single-use’ is quickly falling out of favour, eCommerce plays a significant role in the creation of packaging that is discarded after a single delivery – and this needs to change.

Whether you ship items in cardboard or plastic, you can make efforts to work with manufacturers and suppliers that use recycled materials, purchase carbon offsets, and work to reduce transport emissions.

And with so many companies now offering sustainable packaging, it’s easier than ever for eCommerce stores to make small changes that can have a big impact on the health of the planet.

Further Reading: Plastic vs Compostable Packaging: Which Is Better for the Environment? Read More