Waste Sorting and Abstraction
Shanghai’s waste sorting was implemented on July 1st. I’ve been seeing various posts online — supportive, joking, complaining. Going from no sorting, to recommended sorting, to mandatory sorting will definitely require changing some ingrained habits. Short-term inconvenience is inevitable. I’m no waste-sorting expert, but I want to write about my own experiences with rubbish over the years, along with some personal thoughts.
First, waste sorting should be tailored to each country’s circumstances. What works in one country may not work in another. China has abundant human resources — many labour-intensive things can only be done well in China. For example, same-day delivery is probably impossible in sparsely populated New Zealand. So waste sorting should also be adapted to local conditions.
When I lived, studied, and worked in Shanghai for over a decade, rubbish was basically unsorted. Although there were “recyclable/non-recyclable” bins on the street, from my observation, what ended up in which bin was essentially random. I’d read reports that even when people sorted properly, the collection trucks would mix everything together. So it was largely performative. There were no enforcement measures, and education was lacking. Actually, I think China’s recycling is quite good — because many things can be sold, and some people make a living from recycling, forming an entire industry chain. Even if you don’t sort when throwing away, someone will manually sort out the valuable stuff. This might be an advantage of being a populous country. The cleaner in my old apartment complex had a grandson Qian’s age. They often played together, and I’d chat with the cleaner. They said they’d pick out valuable items from other people’s rubbish to sell — a nice side income.
Later, I studied in Hong Kong. Waste sorting there was better than on the mainland, but still just okay. In school dorms and rented apartments, rubbish was basically unsorted — you could just toss it. Some specific places had specific bins — for paper, bottles, etc. Maybe because they’re next to the mainland, processing is easier. It never felt like a major change or inconvenience in daily life. But it was the first time I learned that things you could sell for money on the mainland cost money to dispose of in Hong Kong — because there’s no scrap recycling industry. Old appliances, mattresses, and other bulky items — in China, you can sell them for cash. In Hong Kong, you have to pay someone to take them. Some appliance stores offer disposal discounts when you buy new items — buy a new TV, they’ll haul away the old one for free. That was an eye-opener for me.
Then I came to New Zealand. A Pacific island nation with nothing around it has to handle its own waste. So waste sorting education and management are much stricter than in Hong Kong or mainland China. I also found it inconvenient at first — even embarrassing at times. Interestingly, waste sorting rules aren’t even uniform across Auckland — some areas are piloting different systems. When we were renting, the area used paid garbage bags. You had to buy special bags; they wouldn’t take regular ones. Pay-per-bag — more rubbish, more cost. Our current area is more traditional — bins. Each household has two bins: one recycling, one landfill. Neither is free — it’s a line item in the council rates. Also, Auckland’s largest waste management company was bought by a Chinese company. I read a newspaper joke: “We must maintain good relations with China, or they won’t collect our rubbish, and it’ll pile up at home.”
Overall, New Zealand’s waste categories roughly correspond one-to-one with Shanghai’s new system. Names differ, and processing methods may vary. New Zealand tends to tell you directly how and where the waste goes, rather than using abstract names like “dry waste” and “wet waste” that confuse people on first hearing.
Recyclables are the same. In NZ, if it has a recycling symbol, it goes in the recycling bin — bottles, cans, etc. Recyclables are shipped to Asian countries for processing. Used to be China; now maybe Southeast Asian countries. New Zealand has no local recycling industry. A colleague once told me: China exports so much to the world but doesn’t import much. Shipping containers used to arrive full and return empty. Then someone had a bright idea — “We can fill them with waste on the way back.” Win-win: the NZ government pays them to take the recyclables away (they make money), and back in China, they sell the recyclables as scrap (making money again).
Shanghai’s wet waste is called food waste here — leftovers, etc. The government allows this to go in the landfill bin. But there are concerns about landfilling food waste, so they encourage people to process it themselves. I’d say it’s half encouragement, half coercion. For example, in areas using garbage bags, the bag is quite large. You’d fill it over about two weeks. But food waste would stink long before then, and you certainly can’t keep it in the house. So you’re forced to find a solution. The typical solution: composting — turning it into fertiliser for the garden. Most houses have a compost bin in the yard. There are several methods — one uses tiger worms (sounds fierce, looks like earthworms). Another uses chemical additives (learned from Japan). I researched it and found if you don’t have enough food scraps, the worms starve. So if someone in New Zealand asks for your leftovers, they’re probably not hungry — they’re afraid their worms will die. Also, keeping a bucket of worms at home — if they escape, it’s pretty horrifying. Chemical composting also requires accumulating enough material. Neither is easy. Our family of three doesn’t produce much food waste anyway. Eventually, we started collecting our daily food scraps in a large lunchbox. I take it to work every day — a long-distance commute with my food waste — because the school has a dedicated food waste bin. First thing at work: dump the food scraps.
Dry waste is called landfill waste here. China might incinerate, but New Zealand landfills. Hazardous waste and electronic waste must be paid for disposal. Occasionally, a colleague will group-email saying they have a TV or appliance they don’t want — who wants it? At first, I thought they were Good Samaritans. Later I realised they just want to save on disposal costs.
New Zealand also has two categories China doesn’t. One is green waste — a New Zealand specialty. Every house has gardens front and back. When plants grow wild — weeding, pruning — you get green waste. You can landfill it, but the government says small amounts in the landfill bin are fine; if the proportion is too high, they can refuse collection. I’ve seen bins tagged with “contaminated — not collected.” Green waste can also be composted. If you don’t want to do it yourself, you pay a specialised company. The other is bulky waste — old furniture, appliances, etc. If you don’t want to pay extra for disposal, the government will collect it once a year (not free — it’s a separate line item in council rates). You have to book online, then haul it to the kerb on collection day.
When I first arrived, waste sorting felt very “inconvenient.” Old rechargeable batteries — you pay someone to take them. Time and money. A friend asked if I wanted anything brought from China before she returned. I said, “Take my broken mouse back to China and throw it away for me.” But the upside: I now think about disposal before buying anything. That’s a form of conservation.
Also, you can’t throw away unlimited amounts. One bin per week at most. Excess has to wait until next week. There’s a silver fern — New Zealand’s national tree — next to my house. The fern leaves are huge. One fallen leaf can practically fill a bin after breaking it up. Two leaves, and you’re out of bin space for that week. Every time there’s a strong wind, I silently pray for those fern leaves to hold on.
Some Thoughts
Naming these waste categories is a skill — like learning object-oriented design. You can’t be too specific — “waste for tiger worms” or “waste shipped to China for paper reprocessing.” You need some level of abstraction. But how abstract is the tricky part. The much-criticised “dry waste” and “wet waste” categories are abstract, but not well-abstracted. Why? In AI terms, the feature extraction isn’t clear. “Dry” and “wet” are characteristics of waste. If you name categories by a single feature, the human classifier will naturally sort by that feature. If it’s wet, it’s wet waste — like “wet wipes.” If it’s dry, it’s dry waste — like “raisins.” But raisins are wet waste, and wet wipes are dry waste. That’s what everyone’s complaining about. If you name waste by its features, you should find the most representative feature. For instance, instead of “dry” and “wet,” call it “can be pulverised by the AT123 shredder” or “cannot be pulverised by the AT123 shredder.”
In object-oriented terms, this is “separation of concerns.” Why are pork bones dry waste but chicken bones wet waste? Because it’s tied to the specific implementation of the processing equipment. The current shredder can handle chicken bones but not pork bones. Similarly, reed leaves are dry waste because the current shredder gets tangled by them. So the dry/wet distinction isn’t based on whether something is actually dry or wet, or even whether it can be composted. The precise classification algorithm is: “can it be shredded by the currently used shredder?” If the shredder is upgraded someday — no longer tangled by reed leaves, no longer jammed by pork bones — then pork bones and reed leaves could be reclassified as wet waste. This kind of “can it be shredded by Model X” decision shouldn’t be left to ordinary citizens.
Second, classification should allow some margin of error. I read that the NZ government spends significant resources every year handling mis-sorted waste. You can’t expect zero mistakes from the public, especially when it involves specialised knowledge. In NZ, we don’t really know if tiger worms can chew through large bones. We throw all food scraps into the compost bin. If the worm really can’t handle a bone, it’ll still be there after composting, and someone will pick it out for landfill — they won’t use it as fertiliser. Similarly with landfill: green waste should be composted, but the government allows small amounts in the landfill bin. Direct burial won’t cause major problems.
I also saw netizens complaining about the multi-step process for disposing of bubble tea. I think that doesn’t require professional knowledge — citizens should gradually learn. New Zealand is the same. McDonald’s drinks: the lid is usually recyclable, but the cup can only go to landfill (because of the waterproof plastic coating). Many condiment bottles require the lid and body to be separated. You’re also supposed to rinse the bottles before disposal. Some ketchup bottles are sticky, and I don’t want to wash them either, but you learn. Also, manufacturers could provide better labelling on which parts are recyclable. In NZ, if you see a recycling symbol, toss it in recycling — that works. But sometimes we buy imported oil, salt, and sauces from Chinese supermarkets, and we don’t know how to dispose of the containers — most don’t say whether they’re recyclable. And we’re afraid of making Chinese people look bad, since the labels are in Chinese.
There’s also criticism about scheduled collection times. New Zealand also has scheduled collection. Different national conditions, so direct comparison may not be fair. Each household has two bins: landfill collected weekly, recycling every two weeks. During holidays, collection doesn’t happen. You have to check the council website for the next collection day. Miss it, and you wait until next time — unless you can’t stand it and drive the rubbish to the transfer station yourself (for a fee).
Overall, I support waste sorting. China is gradually becoming a developed country, and the responsibilities of being a citizen of a major country should gradually align with those of developed countries. Of course, some early-stage hiccups are understandable. I hope things improve over time. Otherwise, the next time I go back to China, I’ll have to do what netizens suggest to avoid fines for wrong sorting: pack my rubbish and ship it abroad to throw away…