starving for gas

Online Opinion | Nowadays not many people seem aware that nearly everything they eat and most of what they drink is produced using nitrogen fertilisers. And nitrogen fertilisers are almost entirely made from natural gas.

Indeed half the world's people would not be here today were it not for the tripling in global food production achieved largely through the use of this invaluable petrochemical byproduct. Admirers of Brillat-Savarin might plausibly contend the present human race is mostly made of gas.

Today’s high-yielding food crops, to a very great degree, depend on high levels of applied nitrogen: without it, yields collapse. Since the Green Revolution the entire world food supply has become more and more critically reliant on this input.

However, worldwide, natural gas reserves are running out just as quickly as oil which, presumably, is why China wishes to secure such a long term contract for gas from Australia and no doubt many other suppliers.

Earlier this month the International Energy Agency's chief economist Dr Fatih Birol told Britain’s The Independent newspaper that world oil production will peak within 10 years. The average rate of decline in the world’s 800 major oilfields is now 6.7 per cent a year - almost double what it was two years ago. "One day we will run out of oil. It will not be today or tomorrow, but one day we will run out of oil and we have to leave oil before oil leaves us. We have to prepare ourselves for that day," he said.

The same story, though far less well advertised, applies to natural gas which, within a few years of oil, will also reach its peak and start to decline. According to the International Fertilizer Industry Association, natural gas currently furnishes the feedstock for 97 per cent of the world’s nitrogen fertilisers. As gas output dwindles these will become increasingly scarce and unaffordable to most farmers, Australia’s included.

Unless a replacement source of ammonia for making fertiliser is found, then quite simply, global food output will - probably quite quickly - revert towards what it was in the 1960s, around a third of what we enjoy today. Those who are tempted to deride this statement can easily test the proposition in the privacy of their own backyard or balcony by growing one lettuce or tomato plant in plain sand with a standard N fertiliser, and one without.

In the 1960s we only had three billion mouths to feed (one billion of them actually starving). By the time the gas runs low and global food supplies start their downward plummet, there will be eight billion humans on the planet. According to UN population forecasts this number will be reached in 2025.

Furthermore about five billion of these people will live in cities. Unlike the 1960s, most will have not the slightest capacity or knowledge of how to produce their own food.