Reducing waste and investing in circular economies must happen to make the materials we use less problematic to get rid of
By 2050, global cities could produce 3.88 billion tonnes of waste every single year. Plastic is a significant contributor to this number. Humanity produces around 460 million tonnes of plastic every year, a figure that is forecast to triple by 2060. Just under half goes to landfill, 17% is incinerated and 15% is collected for recycling, although less than 9% is actually recycled. The remaining 22% ends up in the environment, much of it in the ocean. It’s a problem that can only hinder the global transition towards net zero – unless we do something about it.
As an idea, the circular economy is rapidly gaining traction. Whether at company, city or national level, there is a growing recognition that resources are finite, waste is costly and to deposit ever greater quantities of stuff in the ground is unsustainable. While plastic is an extremely useful invention that has played a large role in human advancement, the dark side of this invention is disposability. The convenience of single-use plastic needs to be rethought to ensure it has a longer, more useful lifespan.
Eliminating single-use plastics – such as disposable straws, utensils, beverage and food packaging, plastic bags, disposable pens and even wet wipes – is a good place to start reducing waste. Reducing the use of single-use plastic requires a shift towards a more circular and sustainable economy, starting in our homes. We all know the three Rs – reduce, reuse, recycle – and this is still the most accessible way for us as individuals and households to combat plastic waste. We can maintain our awareness of how single-use plastic impacts on the environment. We can refuse to use single-use plastics in our homes and offices wherever possible by choosing products that don’t have plastic packaging or, if this isn’t possible, choosing reusable plastics or bulk items instead of single servings and avoiding products with non-recyclable content. We can seek out recycled and reusable alternatives and separate plastics from our waste for recycling.
Large-scale impact, however, demands that governments implement policies that support a circular economy and that organizations throughout the production value chain move away from the traditional, linear process of resource extraction, manufacture, use and disposal towards an approach in which things are instead reused or recycled repeatedly to maximize the lifespan of materials almost indefinitely. This could apply to anything from plastic bags to clothes to entire buildings. To make this more achievable, clearer labeling of plastics to make it easier to sort in the recycling sphere is necessary, as is avoiding composite plastics and plastics that are mixed with other components (such as those used to package potato chips), as these types of plastics are less recyclable.
Building better
Engineering, sustainability and environmental professionals are needed in every industry to monitor initiatives that are designed with circularity in mind and determine their viability for local application.
In infrastructure construction, South African engineers can lead the way, where local engineers have developed customized road design and construction technologies that are viewed as innovative globally. Recycling existing road materials and the use of so-called deeply balanced pavement structures have contributed to the development of an extensive road network at a fraction of what it would cost in most developed countries. Currently, the asphalt used for the surfacing of roads locally comprises 20-25% recycled materials. But more can be done. Innovative materials can replace traditional carbon-intense materials. Asphalt can often be replaced with recycled plastics or rubber from recycled tyres. Replacing carbon-intensive construction materials in buildings with low-carbon alternatives can also play a key role in reducing the construction industry’s overall carbon emissions and waste contributions. Steel can be replaced with fibre-reinforced plastic or polymers or even carbon fibre and graphene under the right circumstances. But not all plastic is equally easy to recycle and converting it for reuse in a more sustainable form isn’t an all-encompassing solution.
Hot topic
There is another way of dealing with plastic: burning it. In Scandinavia, waste-to-energy (WtE) plants incinerate high-energy residual waste, including non-recyclable plastic along with other high-energy wastes such as timber and wood products. The heat is used to generate electricity and to warm water for local district heating systems, reducing the need to burn virgin fossil fuel for power and preventing a wide range of plastics from going to landfills. They do not end up in the environment and the volume of waste is vastly reduced. The exhaust from these plants is well treated, so most of what exits the chimney is water vapour. The residual slag is nasty stuff, though, and the waste from the scrubbing also contains high concentrations of hazardous substances. Unpleasant though these residues are, they are at least relatively small in volume and there is some value in concentrating them so that they can be disposed of appropriately in specialized landfills. New technologies are also putting some of these wastes to use, for example, in new types of concrete where the toxic chemicals can be fixed and rendered harmless.
Could WtE be considered as part of the solution to meet South Africa’s energy requirements as it moves away from coal-fired power stations? According to the latest available statistics, South Africa generates approximately 122 million tonnes of waste per year, of which only 10% is recycled or recovered for other uses. This leaves at least 90% of the country’s waste entering landfills or worse – being dumped illegally.
Text | Alison Groves and John Rammutla
Photography | Kanittha Boon
Alison Groves is Director: Discipline Lead: Built Ecology and John Rammutla is Principal Associate: Highways at WSP in Africa. For more information, go to wsp.com.
