The veggies have an ideological objection to rearing or killing animals for human food and jump on any argument – welfare, environmental, health – to advance their viewpoint. So they are absolutely loving climate change and the global population boom because they can vary their “meat is murder” chant with “go veggie and save the planet”.

The carnivore lobby, usually fronted by the National Farmers’ Union (NFU) but with legions of apathetic meat-eaters subliminally cheering it on, tries to get off the back foot. It questions the extent to which methane from livestock fuels global warming – not always terribly convincingly, but then complex climate-change science isn’t exactly a core competence of the farming community.

The meat lobby is speaking to its strengths, though, when it tries to make theoretical veggies face up to the realities of food production. The NFU points out that more than half of the UK is utterly unsuitable for producing any human food other than meat. Veggies want to dig up any land that looks vaguely green and replant it with wall-to-wall lentils and aubergine. It’s a lovely idea, but it won’t work and the deer and rabbits will have a field day.

A coherent compromise emerged last week that can move this stagnant debate on. Eating The Planet?, a joint report from Compassion In World Farming, the impeccably well-informed and thoughtful animal welfare organisation, and Friends Of The Earth, our foremost environmental group, argues that we don’t need to go veggie to feed a booming world population and save the planet from climate change and forest destruction. It says that we can indeed produce enough food for everyone in the world, but only if we are prepared to ditch factory farming for more natural and humane farming methods.

This makes total sense. Only a half century ago, we never dreamed of eating the quantity of animal products, especially meat, that we do now. Most households ate a chicken only occasionally and made it last all week. An imperial pound of meat, along with some vegetables, was considered a sufficient quantity to make a stew that would serve eight people. Incredible though it may seem, the average European now eats 300 grams of meat and 100 millilitres of milk plus two slices of cheese each day.

This meat and dairy-centric diet has only been made possible by the rapid expansion of cruel and intensive factory farming. Industrial production now supplies at least 74% of poultry meat, 55% of pork production, 68% of eggs and 43% of the beef we consume globally. The UN’s Food And Agriculture Organisation reports that industrial animal production systems have been increasing at six times the rate of traditional mixed farming systems.

Eating The Planet? includes research demonstrating that if people in countries such as the UK were prepared to eat meat or fish just two or three times a week, along with small amounts of dairy products every day, the world’s food needs could be met by humane free-range farming methods.

In other words, we have a choice. We can continue to breed high-yielding, “efficient”, fast-maturing livestock and fatten them up in no time with profligate quantities of grain that would be better fed to humans – just to produce unprecedented volumes of low-grade industrial meat, while trashing the planet in the process – or we can return to rearing livestock on a much smaller scale, using a traditional, extensive farming approach.

The great thing about time-honoured farming methods is their in-built natural constraints. Keep chickens in proper free-range systems and they take around four months to reach maturity. Pack them into a shed and feed them on GM soya and you can give them the chop at four weeks. Native breeds, like our Belted Galloway or Highland cattle, will take as many as three years to reach their final weight if they are out on pasture. But take animals from a modern breed and stuff them full of barley in a shed, and they will be ready for market in 12 to 18 months.

Recalibrating our livestock production away from factory-style processes and back to humane and ecologically sustainable farming methods will reduce the quantity of animal foods we produce and make them more expensive. That is a good thing. Intensive farming has provided us with previously unheard of quantities of “cheap” protein, but it can only be considered so if you put no price on animal suffering and turn a blind eye to the environmental degradation it leaves in its wake.

The absurd last-century idea that eating limitless piles of cheap, low-grade meat and dairy was some sort of democratic entitlement needs to be looked upon as an aberration in world history. We have to reverse the meat-and-two veg expectations of the last half-century. A correction is long overdue. Eating lower down the food chain and making the bulk of our diets more herbivorous and plant-centric is definitely where it’s at.