Cork has a multitude of uses from wine stoppers to cork fabric or leather. The physical properties of cork make it a popular choice. It is lightweight, durable and waterproof. But can the cork oak trees keep up with the demand we place on them? Is cork sustainable? The way that it is harvested makes it one of the most sustainable natural materials out there. A tree does not need to be cut down for the cork to be harvested – it only needs stripped of its bark. And when renewing, it even contributes in the fight against climate change! Let’s delve deeper.
Where does cork come from?
Cork is made from the bark of the cork oak (Quercus suber) tree. These trees exist mainly in Europe and northwestern Africa – Portugal has the largest cork oak tree population and is the biggest producer of cork products.
Once the tree reaches at least a quarter of a century it is ready to be used to harvest cork. From there onwards the bark is stripped every nine (or so) years.
How is cork harvested?
Cork harvesting, done in the months of June and July every year, is very much a craft. It has remained largely unchanged since it began. Harvesting is done manually by a skilled worker using an axe used specifically for this purpose. Damage done to the inner layers could prevent regrowth so getting it right is hugely important.
So, is cork sustainable?
Unlike for wood products, cork oak trees do not need to be felled. After harvesting the bark even renews itself, making for one extremely sustainable resource! Its use will be available for future generations if it continues to be managed correctly.
But it gets better! Just by being, cork oak benefits the ecosystem. They are particularly efficient at absorbing carbon dioxide, a greenhouse gas which contributes to climate change. But after harvest, they absorb even more! It is estimated that they can sequester up to 5 times as much during regrowth. Whilst harvesting other types of trees would result in less carbon dioxide being sequestered, harvesting cork has the opposite effect. It contributes to the fight against climate change!
Cork oak forests also help sustain a wide variety of animal and plant species – some of which are endangered. These forests are some of the most biodiverse in the whole world. Per square kilometer they are estimated to contain 135 different plant species.
Is the cork tree endangered?
There is a common belief that the cork tree is actually endangered. However, this is not the case. Or not at least for the reason you may think. It is not down to our heavy use of cork. In fact, it is the opposite – cork would be endangered by a decline in use in some industries.
The wine industry used to use the majority of cork harvested. However, the industry is now producing more wines sealed with a screw-top rather than a cork. In an age where most businesses are veering towards a ‘greener’ approach, the wine industry has moved away from one of the most sustainable, ecofriendly materials available. Over 90% of New Zealand wines now use screw lids. Whatever the reason, this massively affected the demand for cork.
This drop in demand creates potential problems for the cork industry. With less demand comes the risk of cork oak forests being used for more lucrative ventures. This would prove catastrophic for both the livelihood of locals and the rich forest ecosystems.
In recent years, consumers have become much more aware of how their day-to-day lives impact the environment. And since cork is recognized for its ‘green’ credentials, it has been incorporated into many more products! Cork fabric, also known as cork leather, is a popular choice of vegan leather. The vegan leather market is particularly strong and growing – it is predicted to reach nearly $90 billion by 2025.Cork is well placed to capitalize. It is a particularly popular choice – not only is cruelty-free, it also does not harm the environment in the same way as plastic-based vegan leathers.
The bottom line
In terms of sustainability, it does not get much better than cork. Not only does a tree still remain after harvest, it can also be used time and time again. The fact that the cork oak tree absorbs even more carbon dioxide when it is renewing provides the icing on the cake. Using cork products will contribute to the long-term health of the cork industry. Not doing so is the biggest risk to cork oak trees. A sharp decline would result in livelihoods of locals being taken away and the land being utilized for another purpose. Every little helps, so when you can – go buy some cork!