My wife and I wrap cheese when we put it into our lunchbags. I use plastic and she uses waxpaper. As the waxpaper is at least twice as thick as the low density polyethylene in my lunch bag, I initially create a smaller waste burden in our local landfill. Of course, over time, the waxpaper will decompose and leave room for future generations to contribute to the landfill. After 3 and a half years, the steadily accumulating plastic pile will catch up to the slightly decomposing waxpaper pile but neither will decrease as long as we are both disposing the same amount of waste each week. After 30 years of lunches it will take another 10 years of straight decomposition for the waxpaper pile to disappear, at which time the plastic will all still be there. The virtual indestructibility of plastic poses a problem for our environment. It strikes me, however, that in a world looking for carbon sinks to protect our atmosphere, it might just be an opportunity. Let’s look first at plastic as a problem.
A problem?
Recycling plastic is not working. Only 9% of the plastic ever made has been recycled and another 12% has been incinerated. Recycled plastic competes with virgin plastic based on oil prices and the market for plastic waste has recently been disrupted by China’s ban on imports. Most of the rest of our plastic ends up in landfills near urban centers but a worrying 10 m tons is sent out to sea every year. This latter problem is mostly an issue in developing countries, with 93% of the plastic entering the sea from 10 rivers in Africa and Asia. Because it is floating and indestructible, the plastic serves as buoys in a great experiment that leads to massive accumulation in gyres, the dead zones of oceanic currents. More needs to be done to understand how plastic, an inert substance, interacts with known pollutants to cause health and choking effects for ocean life. One study, the International pellet watch, demonstrates that persistent organic pollutants (like DDT) can be found in plastic pellets on beaches around the world. It is not clear, however, that plastics – by themselves – threaten our food supply or our ecosystems.
A solution?
Plastics are an unlikely hero in the fight against climate change. They are as energy intensive as steel, releasing 2-3 kg of carbon dioxide for every kg of plastic made. Still, there are 2.5 billion tons of plastic in use around the world, often as part of buildings or long term structures – a substantial carbon sink. Is there a way to use their indestructible nature as a means of reducing carbon dioxide in the atmosphere? An important part of any long-term climate strategy is negative emissions, literally removing carbon dioxide from the atmosphere. These are needed to offset any unavoidable emissions , such as those created by making concrete. Plastic films play an important role in several of these scrubbing tower designs, allowing water an extensive thin surface to dissolve the carbon dioxide in the air. The tricky part comes in storing the gas collected in such a manner. The usual answer is underground, which is where the carbon in fossil fuels came from in the first place. There will likely be few places where the geology permits secure storage of carbon dioxide and some carbon emissions involved in moving the gas there. Could plastic production on site be the solution? If so, the current energy intensive methods for producing plastics would have to be dramatically improved.
What can we do?
- In Canada, you can join the conversation about what to do with plastics
- Carbon taxes will be an important way to reveal the hidden costs of using plastics
- Environmental projects in Africa and Asia can help stem the tide of plastic in our oceans
- Start talking about negative emissions. The sooner we start planning on how to take carbon out of the atmosphere, the surer we will be that the climates we know and love won’t migrate somewhere else.