Zero-carbon plastics

Although natural plastics like rubber have been used by humans for thousands of years, it was not until the 1950s, when there were some significant advances in chemical engineering, that synthetic plastics came to the fore. There are now over two dozen types of plastics, which range from commonly used items such as polypropylene in yogurt containers to unexpected uses like acrylic in paint, floor polish, and laundry detergent, as well as micro-plastics in soap and shampoo, nylon in waterproof jackets, and polyester in clothing. Despite their many uses, all types of plastics have one thing in common: they contain carbon. Carbon is useful for creating different materials because it easily bonds with a wide variety of elements, usually hydrogen and oxygen in the case of plastics. Companies that make plastics generally get their carbon from refining oil, coal, or natural gas and then processing the refined products. Plastics are inexpensive because fossil fuels are cheap.

When cement or steel is made, carbon dioxide is released as a byproduct, but around half of the carbon used in making plastics stays in the plastic. Plastics can take hundreds of years to degrade, which is a major environmental problem since plastics dumped in landfills and oceans remain for a century or more, causing harm to marine life. However, in terms of emissions, the carbon in plastics is not a major contributor to climate change, as the carbon atoms that go into plastics are atoms that will not enter the atmosphere and drive up the temperature for a very long time.

Since we don't have a viable zero-carbon plastic, we need to calculate the green premium for plastic using carbon capture as an offset, making the net-zero carbon option for plastic 9-15 percent higher. This isn't astronomical, but people won't want to pay it if they don't have to.

Plastics could actually be a carbon sink in the future, where they remove carbon instead of emitting it, but first, a zero-carbon way to power the refining process is needed, such as clean electricity or hydrogen produced from clean electricity. Additionally, a way to obtain carbon for plastics without burning coal is needed, such as extracting carbon dioxide from the air or obtaining carbon from plants. A zero-carbon source of heat, such as clean electricity, hydrogen, or natural gas with a carbon capture device, is also necessary. If these pieces come together, it would be possible to make plastics with net negative emissions, effectively taking carbon out of the air and putting it into a plastic product, where it would remain for decades or centuries, with no additional emissions.

In addition to finding ways to make materials with zero emissions, we can reduce our use of plastics. While recycling more plastic will help, it is not sufficient to eliminate greenhouse gas emissions. However, it can aid in reducing energy needed to recycle materials. To further cut energy use, repurposed materials should be used, as reusing requires less energy than recycling.