Curbing Concrete
Concrete is popular for both its aesthetics and its practicality. Interior designers love it for that “industrial look” and industry loves it for the fact that it is robust, affordable and versatile. Everything, however, carries a price and the environmental cost of concrete is now becoming so high as to be, literally, unsustainable.
Understanding sand
In the Rhyme of the Ancient Mariner, a sailor looks out to sea and reflects, sadly, upon the fact that they are surrounded by water and yet have no water to drink. Companies producing concrete are faced with much the same problem. The world is full of sand, but most of that sand is located in deserts and beaches. Unfortunately, the sand in deserts and beaches is generally not suitable for use in concrete. Basically, that fine sand which is so prized by holidaymakers (and Instagrammers) is just too fine to be effective in concrete. The best concrete is made with grittier sand from riverbeds or less touristy beaches. This situation creates a direct clash between what is good (in the short term) for the construction industry and what is sustainable, over the long term, for the environment as a whole and, by extension, for the survival of humanity.
Understanding the role of sand in ecological systems
Whenever there is a threat of flooding, one of the standard responses is to put out sandbags. These serve the dual purpose of absorbing water and acting as a physical barrier to its progress. This is a reflection of the role sand plays in the natural world. It absorbs water and slows its flow. When humans collect sand for use in the making of concrete (or for any other purpose), it alters the ecological balance of the location from which it was collected. Slight alterations may be compensated for relatively quickly, but large alterations can build up very quickly to create major, and in some cases, dangerous changes.
Sand excavation from riverbeds
A shallow stream will flow much more slowly than a deep river and as such its ecological system will be very different. When humans remove excessive quantities of sand from riverbeds, they increase the flow of the water and thereby also make it move more quickly. This can not only significantly alter the ecological balance of the river, but also make it more prone to flooding with all the negative consequences that implies.
Sand excavation from beaches
Sand dunes are nature’s flood barriers. Take sand away from them and the seawater can come further and further inland, causing erosion as it does so. Erosion is a natural process, but the removal of the sand causes it to happen in a much faster timeframe, which can lead to damage to the environment.
Solving the problem
In the short term, in fact, very urgently, governments around the world need to clamp down on the illegal excavation of sand from river beds and beaches. Technology may be of huge assistance here, especially blockchain. Although blockchain was developed by and for Bitcoin, it has since developed a life of its own and is becoming increasingly used for tracing the provenance of sensitive goods, from designer handbags to environmentally-sensitive items, such as tropical wood. Over the longer term, however, humanity is going to need to find a way to balance development with sustainability and that is likely to mean a shift away from the use of concrete and/or a shift away from the use of sand in the manufacture of concrete. There are already moves to make this second option a reality. Specifically, research is being undertaken to see if at least some of the sand used in the manufacture of concrete with recycled plastic waste. If it succeeds, it will be two environmental wins at once.
