Thursday, 29 January 2015

Why the world isn't going to run out of food.

Various publications have leapt on some research looking at 'peak-rate years of global resource use' to scare us with a new thing called 'peak food':

Researchers from Yale University, Michigan State University and the Helmholtz Centre for Environmental Research in Germany claim what makes their study alarming is how many staple foods have peaked in a short space of time, and as global population levels are expected to reach nine billion by 2050.

So reports the Independent - indeed they have a suitably alarmist quotation from one of the researchers. The problem is that what the researchers are measuring for renewable resources like food isn't total resource use but the rate of increase. So the rate in the expansion of agricultural land started to decline around 1950 ('peak land' if you want to use alarmist speak) and, the authors point out, "recently stabilized at the highest recorded levels, about 1.8 x 106 ha (Ramankutty and Foley 1999)."

The result of this is:

Since the Green Revolution in the early 1960s, the world's cereal (grain) production has increased by 136 percent - from 877 million metric tons per year to 2068 million in 20031 (Figure 1). Grain yields increased by 129 percent over the same period, from 1.4 to 3.1 metric tons per hectare. Total grain production in the United States (U.S.) also doubled - from 164 million metric tons in 1961 up to 349 million in 2003, accounting for 17 percent of the total global grain production. At the same time, overall U.S. grain crop yields doubled from 2.5 to 5.9 metric tons per hectare, an increase of 136 percent and almost double the global average. Europe experienced similar gains.

So the calories available per capita for the world's population now stand at around 2800 calories per day (and yes, I know that this is pretty unevenly distributed). Given that the NHS recommends an intake of 2500 per day for men and 2000 per day for women all this suggests that there is plenty of scope for us to feed a larger population (about 300 million or so larger).

There's no doubt that we face a challenge to meet the calorie requirements for a growing world population. But this rather questions the typical green left response to this problem (their preference for eugenics aside) - talking about local sustainability, resiliance and self-sufficiency. The authors of this study also report on 'peak energy':

The available data suggest that peak-rate years for several nonrenewable resources, i.e., coal, gas, oil, and phosphorus, have not yet occurred.

This suggests that there is plenty of scope to meet energy needs without taking up valuable agricultural land to do so. About 10% of agricultural land is given over to 'biofuels' and other forms of non-food crop - that land would provide enough food (depending on whose calculation you use) for around 250 million people.

The other consideration is crop yields. The 2013 yield per acre for the USA is 7340 kg/ha which compares to a world average of around 3500 kg/ha (it was 3563.54 kg/ha in 2010). If all yields rose to the level in the USA world food production would more than double. If yields reached the levels of Belgium (9213 kg/ha) then world production would be 2.6 times higher - enough to feed a world population of 23 billion much more than even the most dire predictions of the population doomsters.

Finally there are prices. If we were seeing real pressure on supply we would expect to see food prices rising. Here's the FAO Food Price Index since 1960 - it doesn't suggest that there's much of a problem:

This 'peak food' thing makes for a nice story (and I guess we need to be challenged) but the data really doesn't suggest that the world is running out of food or indeed anywhere close to running out of food. And I know one thing for sure - autarky, self-sufficiency, community resilience, agricultural protectionism and anthropomorphic attitudes to animal welfare will make things worse. The very greeny-greeny left that gets all agitated by things like 'peak food' are the very people who always propose solutions that would merely make matters worse.


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