Usually, our roads and motorways are made of concrete. The mixture of sand, water and cement is cheap, stable and easy to form. But when it comes to the CO2 balance, the building material does not make a good impression at all.
According to the Intergovernmental Panel on Climate Change, three billion tonnes of CO2 are emitted annually in the production of cement. The amount of CO2 needed to produce just one cubic metre of reinforced concrete must be compensated by 4,000 trees for one day through photosynthesis. To put the whole thing into perspective: A new 3.2 km long construction section of the A100 motorway in Berlin required 500,000 m³ of concrete.
No wonder, then, that alternatives are being researched all over the world. Now a pilot project is being implemented on three motorway sections in northern Spain. Instead of concrete, a thick layer of burnt and pressed recycled paper is used as a binder. This can save up to 75% of CO2 emissions through the EU project "Paperchain" (https://www.paperchain.eu). Not only is the feasibility being tested, but also how long the paperchain can withstand heavy lorries and masses of cars.
Let's hope that the project is successful and that we will see the waste paper layer on many more roads in the future.