FSC-Certified Hardwood Sleepers vs Plastic Sleepers

It has been reported that Network Rail will be switching from timber sleepers to composite sleepers made of recycled plastics for their railway tracks, starting from June of this year. They cited sustainability concerns around timber as their reason for doing this, stating that they will save 30,000 tonnes of CO₂ in carbon emissions by making the switch. At EcoChoice, we have been promoting timber as an eco-friendly and low-carbon solution for decades, so we wanted to take a closer look at the facts behind the statement.

How do timber sleepers really compare to plastic sleepers? Is Network Rail making the more eco-friendly choice for Britain’s railways? Let’s take a look.

Timber vs Plastic – CO₂ emissions

Timber CO₂ Emissions

Timber is well-known for its carbon sequestering properties, absorbing CO₂ as the trees grow and then storing it safely in the wood for decades to come. In fact, around 50% of the dry weight of timber is made up of stored carbon, keeping it out of our atmosphere. In fact, the UK Government’s published NetZero strategy plans to “increase the use of timber in construction to help reduce the embodied carbon in the built environment”.

In simple terms, timber is carbon-negative; it absorbs more carbon dioxide than it creates – that is why planting trees is the key component to virtually all carbon credits.

Of course, carbon emissions can then be added during the processing and transportation of the timber, but these should not differ from alternative materials which do NOT start life as carbon-negative!

Recycled Plastic CO₂ Emissions

Unlike timber, recycled plastic is not carbon sequestering. Before it is recycled, virgin plastic is a heavy pollutant from the petrochemical industry, requiring on average 3.5kg of CO₂

emissions for every kg of plastic produced.

On top of that, the process needed to recycle plastic products into the sleepers will require more transport and manufacturing energy and the consequent release of further CO₂ into the atmosphere, with every kilogram of recycled plastic emitting another 1.6 kg of CO₂ on average (just from processing the waste plastic into a recycled, usable plastic). There will also be additional emissions from turning recycled plastic into sleepers.

Even if the plastic is coming from post-consumer sources, it is merely addressing the problem of landfill, not that of carbon emissions.

Looking at these figures, it is tricky to see how recycled plastic sleepers will cut emissions by 30,000 tonnes. Timber is naturally sequestering, while recycled plastic creates CO₂ emissions so it is hard to understand the environmental calculation used to justify the transition from sustainable timber to polluting plastic.

Timber and Deforestation

The report also cites deforestation of tropical rainforests as a reason for switching to recycled plastic. We would like to challenge that blanket notion.

Here’s why: the FSC. Over 30 years ago, the FSC was created to solve the problem of deforestation, setting standards for sustainable forestry and creating a traceable chain of custody system for the timber coming from forests which followed their sustainable forestry standards. Since then, it has become the leading and most trusted international system which provides third-party assurances that FSC-certified timber is not only protecting forests against deforestation, but is also actively helping to support valuable complex biomes such as tropical forests as well the people who depend on them.

Considering how readily available independently certified timber which can be traced back to deforestation-free sources is, Network Rail should reconsider its shift towards non-renewable plastic. Instead, it should support the FSC system, aligning itself with numerous public and private organisations globally that are committed to reducing carbon emissions while actively safeguarding vital forest ecosystems.

On the FSC site, they describe how their certified trees are felled “responsibly to prevent deforestation and forest degradation”. They also make it clear that any old-growth forests are identified and maintained, preventing those century-old trees from being cut down.

At Ecochoice, we support independent sustainable traceability labels such as the FSC and PEFC since they not only prevent deforestation, but also foster sustainable practices such as the preservation of their high-conservation areas as well as the communities which depend on them. When you look at these in conjunction with the amazing carbon benefits of timber, it is hard to find a better alternative. Even politically correct recycled plastic cannot offer as many benefits, especially when you consider the emissions mitigation hierarchy which states that we should focus first on the reduction of carbon intensive products such as plastic, before considering the stage of recycling. We therefore need less plastic and more timber to safeguard our future.

This report from Network Rail has mistakenly tarred the entire timber industry with the same brush, when that really is not the case in point. When procuring timber sleepers and beams, they do not have to be complicit in deforestation. By purchasing fully FSC Certified timber they would actually be giving sustainably managed forests a viable business and vastly reduce the risk of them being deforested to make way for other uses such as livestock, soy or palm oil plantations.

Problems With Recycled Plastic

While using recycled plastic in place of raw plastic for applications where there are no better alternatives is a more eco-friendly choice, recycled plastic does come with environmental concerns.

The report states that the transition helps to create a circular economy, but Greenpeace thinks otherwise. The leading environmental group has said that recycled plastic is not circular at all and that, because plastics will never biodegrade and are so damaging to the planet, they should never be labelled as circular.

It has also been found that the process of recycling plastics releases vast amounts of microplastics into the environment, which can leach toxic chemicals into soil and water and even inside all of us. Moreover, recycled plastic may contain more toxic chemicals than raw plastic, and it may not be safe for recycling workers and the end consumer.

While there is definitely a place in our society for recycled plastics, it should not become an easy way to label a project as ‘green’ when it is still so problematic. With a transition which is being marketed as specifically for sustainability, a move from timber to recycled plastic does not align with the goals set out. In fact, the emissions mitigation hierarchy points out that the most important step would be to reduce the use of plastics. This would then make landfills less of a problem and therefore recycled plastic less of an attractive diversion from the real problem – our over-consumption and reliance on plastic.

If National Rail finds becoming circular important, they could instead invest in sustainably sourced and where possible even recycled timber products. Timber is:

• A tried and tested solution
• A vital carbon store for our planet.
• Both biodegradable and renewable.
• Durable.
• Cost-effective.
• Has negative or very low carbon emissions.

It is the obvious choice for an industry wanting to reduce its emissions.

The Bottom Line

The negative stigma about using tropical timbers being bad needs to be challenged, It is not the material or the country it grows in that is the issue, it is about how that forest is managed, if purchased from fully FSC Certified sustainably managed forests, you are not only protecting forests, rivers and biodiversity against deforestation but also ensuring the well being of the local wildlife and indigenous people. If there is no market for these sustainably managed timber products, the risk of those forests being bulldozed and re-purposed for holding livestock, growing soy or palm oil increases dramatically!  We need to stop making excuses and finding ways to use harmful plastics – just stop producing them!

If you agree and you would like to source sustainable timber for your next project, do get in touch with our team today. As you can see, we are quite passionate about eco-friendly construction! We are also experts in the timber industry and will be happy to help you find the greenest choice for your project.