One of the most fascinating and affecting pieces of journalism I have ever read appeared in an edition of Rolling Stone magazine in early 2007. An investigation into pig farming, and more specifically the environmental impact of America's top pork producer, Smithfield Foods, it spoke of how "500,000 pigs at a single Smithfield subsidiary in Utah generate more faecal matter each year than the 1.5 million inhabitants of Manhattan" and estimated that this one company alone produced more than 26m tonnes of waste annually. "A lot of pig shit is one thing," the article's author, Jeff Tietz, remarked. "A lot of highly toxic pig shit is another."
It was Smithfield Foods I thought of this week, when I read of a report published in Environmental Research Letters, which advised that we reduce meat consumption by 50% over the next 40 years if we are to save ourselves from environmental catastrophe.
The author of the report, Eric Davidson of the Woods Hole Research Centre in Massachusetts, advised that with great urgency we must cut back on both portion size and the quantity of meat we eat in an effort to reduce the amount of fertiliser we currently use – particularly in the west, but also in developing nations, where increasing prosperity has also brought a rise in meat consumption.
Fertilisers of course release nitrous oxide, one of the gases that cause climate change, and crops grown to feed animals produce more greenhouse gases than those used to feed humans. And this is before we have even addressed the gases released by animal manure – a highly toxic combination of fertilised feed, and all the antibiotics, vaccines and insecticides used to keep factory farmed animals "healthy".
Consider, too, the recent studies that have linked our use of pesticideswith the devastation to the bee population, and just how bleak a future without bees looks: a world in which we must hand-pollinate our crops, and where – as already happens in the US – bees are driven around, farm to farm, to pick up the work of their obliterated wild cousins.
And lastly, think of the size of the average burger. In 1955, when McDonald's first introduced its hamburger, that burger weighed 1.6 ounces. Today, its largest hamburger weighs eight ounces. And in the highly competitive fast food industry, comparatively speaking, the Big Mac isn't even really that big any more.
All of this has repercussions – not only for our waistbands, or even the fact that producing clothes to fit those expanding waistbands requires the production of more fabric; and not even just for our own health, the strain on our hearts and lungs, the drain on our health services, the vast sums we spew on diet products and gym membership, the cost of building bigger aeroplane seats, cars and coffins to accommodate our growing bodies. No, our slavering greed, our lust for enormous portions, affects how much meat our farming industry is expected to produce – and not only produce, but produce quickly and cheaply; demands that increase the need for fertilisers, insecticides, antibiotics.
That we could protect our own futures and those of subsequent generations by maybe holding off on the ham sandwiches seems not the greatest of sacrifices. But the problem is that nobody – least of all privileged and still-prosperous westerners, likes to be told what they should or should not eat. We are spoiled rotten; an indignant gang of Veruca Salts and Augustus Gloops, determined that we should have as much belly pork or beef bourguignon as we want or crave, whenever we want or crave it.
But if we have learned anything from the current economic crisis, it should surely be that we cannot expect to have jam today and jam tomorrow. In environmental terms, we have bought on credit, we have maxed out our cards and gone way, way over our overdrafts.
And maybe what will save us is a great scientific bailout: a grand solution of artificially created meat, or a new generation of fertilisers, or robot bees, or whatever. Or maybe, just maybe, it's time for us to exercise a little self-restraint.