Just bury your trash

This piece is featured in Issue 25 of Works in Progress. Subscribe today to get an issue every two months delivered straight to your door.Alex Chalmers and Rob Wiblin explain why recycling isn’t quite what it seems.Every child is taught that landfill is the worst place our trash can end up. It is the sad consequence of a failure to recycle: a mountain of waste leaking chemicals and smells, blighting the land forever.What if that picture is wrong? What if landfill, properly done, is actually one of the cleanest, cheapest, and most environmentally sensible things we can do with our waste? It turns out that for much of what we throw away, the humble landfill beats the recycling bin.The case against landfill has two parts. The first part is that there are efficient, cheap, or environmentally friendly ways to practically reuse or recycle materials, rather than landfilling, meaning that there is a reasonable alternative. The second is that landfill itself is unsustainable, or environmentally unfriendly, meaning that we need an alternative. Both are false.It’s natural to assume that reusable always means better. But this intuition treats different materials as interchangeable and ignores the cost of making them in the first place. Once we account for energy, labor, and other inputs, reuse pays off only in selective cases.Producing tiny slivers of plastic uses almost no energy. Making the polyethylene resin for a single thin plastic bag, then blowing and sealing it, uses something like 0.6 megajoules, roughly the same energy as a kettle uses for forty seconds. By contrast, cotton is extremely energy intensive, partly because cotton bags need to be much thicker to work, and weigh around 200 grams as compared to eight grams for polyethylene. Instead of a simple blowing and sealing process, the cotton must be made into yarn, woven into fabric, prepared, dried, sized, dyed, and finished, which takes around 1,725 megajoules, around 3,050 times as much energy.In total, Britain’s Environment Agency calculated that a conventional cotton bag needed to be reused 173 times to beat plastic. Denmark’s equivalent public body estimated a similar ratio. Sufficiently well-worn cotton tote bags can beat plastic for environmental cost, but only for the most consistent among us.The same pattern shows up almost everywhere we have tried to replace disposable goods with durable ones. Steel is more energy intensive than plastic, and a steel straw requires 10 grams of steel, compared to just 0.2 grams of plastic for a plastic straw. So even if the steel is never washed (hot water is also energy intensive), it would take 150 reuses for a steel straw to use fewer resources than a plastic one. And who would go without washing it?A ceramic mug only beats a polystyrene cup on energy use after 1,000 uses, and even then only if your dishwasher is fairly efficient. Run a less efficient one and the disposable cup wins on energy forever. Cloth diapers feel greener than disposables, but once you account for the cotton, the laundering, the hot water, and the detergent, the UK Environment Agency found the two are roughly tied in overall demand on resources. A returnable milk bottle takes much more energy to produce and much more fuel to transport than a plastic carton, and has to make around ten or more trips to use less energy than a bottle made from polyethylene plastic.The case for recycling to avoid using virgin material is much stronger when it comes to metals. Recycling 1 kilogram of steel saves 1.4 kilograms of iron ore and uses 65 percent less energy. For aluminum, the energy savings from recycling can be as high as 95 percent. This is because making metal from scratch requires extremely energy-intensive chemical reduction of ores, while recycling primarily involves remelting metals already in their elemental form. Because recycling metals is cheaper than mining, refining, and smelting new ones, the world does an awful lot of it. About 30 percent of the metal used in steel production globally is now recycled scrap.The best case for recycling is where the materials themselves are scarce, and we can more cheaply reuse them than finding more of them. Batteries and electronics contain metals like copper, cobalt, lithium, and nickel. While we are not about to run out of any of these materials globally in a strict sense, their supplies are limited in practical terms. Plenty of copper ore remains in the ground, but it is getting harder and more expensive to extract as the highest quality and most accessible deposits have been depleted. In the case of cobalt, lithium, and nickel, production is geographically concentrated, meaning countries without natural supplies of their own have an interest in recycling in order to limit their dependence on imports. All of these, especially copper and nickel, are highly recyclable, with little loss of quality over multiple reuses. For these, recycling is sensible.By contrast, there is no danger of running out of paper. We can always grow more trees, and that is in fact a decent way of removing carbon from the atmosphere. The silicon used to make glass is one of the most abundant elements on Earth.American plastic comes from ethane, extracted from natural gas. The alternative to making plastic with it is to leave it in the gas stream, slightly increasing the heat it generates. One kilogram of ethane, left in the stream and made into electricity, could power a typical US house for a few hours, or it could be made into 100 shopping bags. The US has proven reserves of shale gas that could last for nearly a century at current rates, and this could increase further with the discovery of new deposits.ShareThe rest of the world makes plastics from propane, butane, and naphtha, meaning from crude oil. We will eventually exhaust this source, but not anytime soon. What’s more, plastics use very little, which is why carrier bags are still so cheap. One 13-kilogram propane cylinder, the kind a family might use to power their gas grill, could instead be made into about 1,600 typical eight-gram plastic carrier bags, three years of a family’s ten-shopping-bag weekly shops.Recycling is a straightforward process conceptually: collect waste, reprocess it, and turn it back into useful material. That picture breaks down once you look at what happens to waste after collection. Much of what is sent for recycling is never recycled. About 25 percent of items placed in American recycling bins are contaminants: for example, lids on containers, food, or damp paper. The number may be even higher, as the vast majority of US states do not consistently track contamination data. This can make the process energy or labor intensive and therefore expensive.Reducing the contamination rate is challenging. Education programs have proven largely ineffective. The best single method for discouraging recycling contamination is cart tagging, where waste collection crews check the contents of a recycling bin and leave it unemptied if contaminated, affixing a tag explaining what was wrong. Despite being the single most forceful and labor-intensive curbside method, a cart-tagging program in Oregon succeeded in reducing contamination by only 29 percent over five rounds.The imperfect recycling process means that putting low-value plastics (such as plastic film, black plastic food trays, or small items like bottle caps and straws) into the recycling bin can sometimes be actively harmful. Since these items are hard to recycle and are often screened out and sent to landfill, they may actually add to the contamination rate (as well as the time and labor needed for processing) without ever becoming useful recycled material.Many mid-value plastics, like the polypropylene used in plastic bottles or butter tubs, require intensive washing. This removes contaminants but also detaches potentially recyclable plastic fragments, meaning the resulting mulch must be filtered. After the washing, the plastic is melted and filtered for contaminants a second time before being turned into pellets. Yield losses can be as high as 45 percent.While the environmental case can hold up for things like plastic soda bottles, where minimal processing is needed, it quickly drops off as you go down the quality scale. For mid-quality plastics like butter and margarine tubs, recycling one ton of plastic prevents the emission of 0.43 tons of carbon dioxide compared with using virgin material. At the same time, recycled tub-grade plastic typically costs hundreds of dollars more per ton than virgin plastic. This means that consumers are effectively paying over a thousand dollars to save one ton of carbon dioxide. By contrast, direct air capture, which removes carbon dioxide from the atmosphere, currently costs an average of $490 per ton, and area specialists hope to lower the cost to $100 per ton in the coming decades. Recycling has its virtues, but recycling plastic to save energy just doesn’t add up.Pro-recycling campaigns portray a world where unrecycled plastic bags, straws, and toothbrushes choke the world’s oceans. This worry has led governments to restrict or disincentivize single-use plastics. But much of this is environmental theater.Richer countries have near-universal refuse collection and almost none of their waste winds up in the ocean. In low-income countries, however, over 90 percent of waste is improperly managed, and typically ends up dumped, burned, or escaping into waterways. Plastic flows into the ocean overwhelmingly come from a small handful of rapidly growing Asian economies. Approximately a hundred rivers, mostly in South and South-East Asia, account for half of ocean plastic. And a substantial share of plastic in the ocean isn’t domestic waste at all, but rather discarded fishing gear.Ocean litter is a huge environmental problem, and solving it means building cheap, effective, and safe waste management in those countries where it originates (plus perhaps cleaning the oceans