For years the pig bin was a part of every canteen and kitchen, but then it was banned. Now campaigners want to bring it back

Pigswill used to be big. Edd Colbert, campaign co-ordinator of the Pig Idea (more in a minute) has written a great piece on how we should be filling pig bellies not bins and points out most parents and grandparents remember the pig bin at school into which scraps were scraped and collected by local farmers.

Oh dear, I'm pretty sure I remember our leftover primary school dinners being shovelled in the pig bin, too. Nobody judged. It was part of the lunchtime cycle. Don't worry if you have similar food-waste reminiscences, they don't date you as much as you might think. Feeding pigs on leftovers from the catering industry was common practice up until the 1990s. Then it was banned.

In 1996, following the BSE crisis, the practice of feeding meat and bone meal, ie dead animals, to omnivores was outlawed. Good you might say.

Then another seismic health scare in February 2001 when the foot and mouth outbreak began at Burnside Farm, Heddon-on-the-wall where pigs were fed on swill (albeit swill that was later found to be illegally untreated). When 3m animals had to be slaughtered prematurely (Jonathan Freedland's piece from 2001, the writing was probably on the wall for the practice of keeping our waste food in the food cycle. In 2002 there was a blanket ban across the EU. The authorities were taking no chances. That's the history. The reason is harder. (Even at the time it wasn't clear cut as a contemporaneous piece from the Guardian makes clear, directly asking if pigswill really was to blame? And also makes the point that the waste at Burnside should've been treated.

I'm glad we're having this chat now, because there's a growing and vociferous band who think the law against pigswill stinks (including this heartfelt blog, Bring Back Pigswill). First, the blanket use of "catering waste" (defined somewhere in the appendix of an EU regulation as identified by this forthright blog on the subject) confuses everybody. In fact, we could be feeding our pigs spent hops from breweries, whey from dairies and surplus bread from bakeries, but apart from some committed pioneers few are prepared to take the risk (punishment for feeding your pigs food byproduct is severe).

For chapter and verse on the holes in the pigswill ban turn to Meat (Permanent Publications, 2010), and specifically the chapter, The Plight of the Pig in the Nanny State, by author and farmer Simon Fairlie. He makes the point that while the world mines phosphorus to exhaustion, slaughterhouse waste – rich in this crucial mineral – is incinerated. And he demonstrates that outlawing swill has created a protein gap, filled by cheap soy products. The true price is picked up by the planet as rainforest is felled and burned to make way for vast soy monocultures. As thepigidea.org puts it: "Almost all (97%) of global soy production is used for animal feed, and European imports of soymeal increased by almost 3m tonnes in the two years immediately following the pigswill ban."

Furthermore, the ecological idiocy of sending food waste to landfill and incineration (even anaerobic digestion often cast as a bright green saviour recoups only 0.5 to 1% of the energy value of food waste) verges on obscenity when you consider how much food we waste: according to Wrap (which promotes recycling), we still chuck away 4.4m tonnes of avoidable food waste a year. Over half of what's in the bin, has no business being in the bin.

Longtime waste campaigner Tristram Stuart and restaurateur Thomasina Miers have a clear plan: edible food should be used for humans as a priority, then pigs. Pigswill needs to make an urgent comeback (with centralised treatment controls. They aren't cavalier about microbiological risk) for the sake of the environment and for farmers (who they argue are being conned out of a cheap source of protein. There is more pro-farmer support for the idea from this piece from the Western Morning News which also makes the point that in Japan swill-fed pork is marketed at a premium as "eco-pork", in recognition of the waste and greenhouse gas emissions it avoids). You can sign up to their Pig Idea and take the Pig Pledge, support their rallying cry – "Filling pig bellies, not bins" –and become a Ham-bassador. Yes, I'm afraid the capacity for swine related puns is hard to exhaust, yet this is serious stuff.

Green crush

Act against the ugly side of the fashion industry, and make something beautiful. That's the ethos of the Craftivist Collective, a group of craft activists who excel at nonviolent protest acts. In the run-up to September's London fashion week, they're putting their spin on War on Want's Love Fashion Hate Sweatshops campaign, which has had a heightened resonance since the collapse of Rana Plaza in Bangladesh. The craftivists have developed a kit so protestors can cross-stitch their own mini protest banners.

Carbon click

The online equivalent of the carbon footprint. The annual carbon emissions created by the electricity used to power each Facebook user's account is the same as the energy needed to make 12 lattes.

If you have an ethical dilemma, send an email to Lucy at lucy.siegle@observer.co.uk or visit theguardian.com/profile/lucysiegle to read all her articles in one place