Tristram Stuart

Seasonally ploughing and harvesting crops will mash up a few moles, slice through a burrow of field mice and crush any ground-nesting bird chicks. Far more significant, however, is the creation of the field in the first place: an act that replaces entire ecosystems, along with all their animal inhabitants.

In the United States, under 3 percent of municipal food waste - so that's the food scraps that goes into people's garbage cans - actually gets recycled. If you go to a place like South Korea, the exact reverse is the case. It's about 3 percent that doesn't get recycled.

In Kenya, where there isn't the luxury of feeding grains to animals, livestock yield more calories than they consume because they are fattened on grass and agricultural by-products inedible to humans.

We domesticated pigs to turn food waste back into food. And yet, in Europe, that practice has become illegal since 2001 as a result of the foot-and-mouth outbreak. It's unscientific. It's unnecessary. If you cook food for pigs, just as if you cook food for humans, it is rendered safe. It's also a massive saving of resources.

Once food gets into our fridges, larders and kitchens, ensuring that it gets used up before going off seems like an obvious thing to do - but it's alarming how many millions of tonnes are simply chucked because we don't keep track of the food we've spent our money on.

Food redistribution is one of the best win-win solutions for food waste avoidance. Food companies can often save money by donating food rather than paying the £80 or so per tonne in landfill tax and disposal costs.

Supermarkets didn't even want to talk to me about how much food they were wasting. I'd been round the back. I'd seen bins full of food being locked and then trucked off to landfill sites, and I thought, surely there is something more sensible to do with food than waste it.

The purpose of farming is to deprive other species of the land and sequester it for our own use. But by perfecting the art of monoculture, it has become too easy for us to exterminate everything else, leaving no wild plants, no food for insects, and a barren land for birds.

The job of uncovering the global food waste scandal started for me when I was 15 years old. I bought some pigs. I was living in Sussex. And I started to feed them in the most traditional and environmentally friendly way. I went to my school kitchen, and I said, 'Give me the scraps that my school friends have turned their noses up at.'

The Feeding the 5000 campaign is inviting food businesses to sign up to the principles of the Food Waste Pyramid tool, which illustrates a simple set of steps that any food business can take to avoid and reduce food waste.

A hunk of beef raised on Scottish moorland has a very different ecological footprint from one created in an intensive feedlot using concentrated cereal feed, and a wild venison or rabbit casserole is arguably greener than a vegetable curry.

Liver, lungs, heads, tails, kidneys, testicles, all of these things which are traditional, delicious and nutritious parts of our gastronomy go to waste.