Ours is the first generation than can largely take plentiful, cheap food for granted. Now, report after report is suggesting it may also be the last.

Two days ago, a Ministry of Defence study of “global strategic trends” raised the spectre of global demand outstripping supply over the next 30 years. And two days earlier, a Commons committee warned that Britain’s own food security is imperilled.

Prices have been rising twice as fast as general inflation and appear to be accelerating. The MoD report suggests that they could eventually settle at twice their present level.

And a groundbreaking government “foresight” study concluded in 2011 that they’re likely to become more “volatile”, making abrupt “spikes” – such as the one that doubled wheat and maize prices in just 12 months in 2007-8, increasing world hunger and provoking widespread riots – “inevitable”.

That report blamed an “unprecedented confluence of pressures” over coming decades, as world population soars and a rapidly growing Asian middle class increases consumption, while “competition for land, water and energy” intensifies and “the effects of climate change become increasingly apparent”.

Demand is projected to double, Prof Tim Benton of Leeds University told the environment, food and rural affairs committee, but “under some scenarios of change… it might be difficult even to produce the same number of calories as we do at the moment”.

As the report shows, Britain’s own production has been declining, even as world supplies get scarcer. Twenty years ago, we produced 87 per cent of our food; now it’s just 68 per cent.

The country may still enjoy “a high level of food security”, it said, but this “will not last” unless ministers quickly change course. Instead, it added, they risk complacency.

You can say that again. Environment minister George Eustice told the MPs he was “content” with the situation. His department does not intend to re-examine it until the end of the decade. The official line is that we will always be able to buy what we need on world markets. But that is to be indifferent to price, at a time when more than four million Britons already suffer “food poverty”.

Of course, we should not aim for complete self-sufficiency. That would put us at risk of bad weather or disease at home; besides, we can’t grow bananas in Bedfordshire, or coffee in Kent. But, with little new land available, we need to grow more on what we have got.

Traditionally, that’s been done by dousing crops with increasing amounts of fertilisers and pesticides, a practice long reinforced by the Common Agricultural Policy. But returns are diminishing: wheat yields have stagnated over the past 20 years after almost trebling in the previous 50. Indeed, the overuse of such chemicals exhausts soil and devastates ecosystems on which long-term healthy agriculture depends.

The latest panacea – much touted by the Government – is GM crops. But, as even Mr Eustice admitted, they “have not generally led to higher yields”. More conventional breeding, using uncontroversial biotechnology, as he added, works “far more quickly”. In some cases, it has quadrupled production.

New farming techniques also offer much promise. New computerised systems can identify 26 species of weeds, enabling tiny “micro-droplets” of herbicides to be placed on each one, cutting chemical use by 99 per cent. And GPS can direct machinery along a few tramlines in each field, minimising crop damage and ground compaction, and thus increase yields by up to 18 per cent.

But the greatest need of all is perhaps the most neglected: conserving and improving the all-important soil, thus reversing the erosion and loss of organic matter that costs the country more than £120 million a year. Yet ministers appear to have no plans even to survey England’s soils.

Applying manure and compost, minimising tilling, and growing cover crops to plough in, provides the ground with nutrients, enables it to retain more water (thus replenishing groundwater supplies and reducing flooding), and absorbs carbon to combat climate change. And, of course, safeguarding soil is yet another reason to concentrate development on brownfield land.

Eating less red meat, also good for health, would also help. It takes over 10 kilos of grain – and 20,000 litres of water – to produce a single kilo of factory-farmed beef: ending the practice worldwide would release enough cereals to feed another three billion people. And it’s important to cut the food waste that ensures that a third of what is grown is never eaten.

It’s all doable. Britain can continue to enjoy food security, and it can be spread even to a much bigger global population. But we urgently need to stop losing ground.