Environment#3: Resource Limitations ~ Food

Photo by: Bern@t

For some background reading on related issues, try these articles first:

Environment#1: The Issue of Human Population Growth

Energy#1: What is Peak Oil

Environment#2: Resource Limitations~ Water

It’s time to start thinking about Food Security

When you think about the factors affecting food production (climate, water, arable land, fertiliser, energy) it’s easy to see how current trends in each of these areas should be making us feel a little nervous about our Food Security (or lack thereof).

Even more than other oil-driven sectors of the global economy, food production is showing signs of strain as it struggles to maintain productivity in the face of rising population, flattening oil production and the depletion of essential resources such as soil fertility and fresh water. According to figures compiled by the Earth Policy Institute, world grain consumption is starting to exceed global production. Global grain reserves have fallen to 57 days from a high of 130 days in 1986.

The production of an adequate food supply is directly dependent on ample fertile land, fresh water and energy. As the human population grows, the requirements for these resources also grow.

The Decline of Fertile Cropland

During the past 40 years nearly one-third of the world’s cropland (1.5 billion hectares) has been abandoned because of soil erosion and degradation. ~ Food, Land, Population and the U.S. Economy, Pimentel and Giampietro

At present, fertile cropland is being lost at an alarming rate. More and more of the world’s cropland has been abandoned because agricultural practices, overgrazing and deforestation have caused the land to become unproductive. This is a long term problem because it takes 500 years to form 25 mm of soil under agricultural conditions. Most replacement of eroded agricultural land is now coming from marginal and forest land.

World cropland per capita has been steadily declining and is now less than 0.23 ha per capita; and down to as little as 0.08 ha in China, the world’s most populous country. To enjoy a diverse diet similar to that of the U.S. and Europe, 0.5 ha per capita of cropland is required. With more of the world desirous of a western diet, it’s obvious that more pressure will be applied to the arable land that remains.

In addition to losses from erosion and other environmental impacts, cropland is also being converted to non-farm uses. This doesn’t just apply to developing nations. One only has to look at the housing developments here in Southern California to witness how much productive cropland is being lost to construction. The number of vehicles in the world also continues to grow, claiming even more cropland for roads, highways, and parking lots. China has recently overtaken the U.S. as the largest vehicle market in the world. If the Chinese market were to keep growing to an ownership rate of one car for every two people, the country would then have a fleet of 650 million motor vehicles, compared with only 35 million today. Since at least 0.4 hectares of land has to be paved for every 20 vehicles added to the fleet, this would require paving nearly 13.3 million hectares of land — an area equal to half the rice fields in China.

The shortage of productive cropland combined with decreasing land productivity is, in part, the cause of current food shortages and associated human malnutrition. When combined with other factors such as political unrest, economic insecurity, and unequal food distribution patterns food shortages are likely to become worse in the future.

Water shortages = Food shortages

Of all the environmental trends that are shrinking the world’s food supplies, the most immediate is water shortages. In a world where 70 percent of all water use is for irrigation, this is not a small issue.

The drilling of millions of irrigation wells has pushed water withdrawal in many countries beyond recharge rates from rainfall, leading to groundwater mining. As a result, water tables are now falling in countries that contain half the world’s people, including the big three grain producers — China, India, and the United States. ~Spiegal Online International

Fossil aquifers which are being use more and more for agricultural irrigation, are not replenishable. When they reach depletion in more arid regions, such as southwestern United States or the Middle East, it can mean the end of agriculture altogether.

In China, the water table under the North China Plain, an area that produces over half of the country’s wheat and a third of its corn, is falling fast. Overpumping has led to the drilling of the region’s non-replenishable deep aquifer, which is dropping at a rate of nearly three meters per year. A World Bank report predicted “catastrophic consequences for future generations” unless water use and supply can quickly be brought back into balance. As water tables fall and irrigation wells go dry, China may soon be importing massive quantities of grain in addition to the soybean imports which now account for nearly 70% of the country’s consumption.

The progressive worldwide depletion of aquifers is making further expansion of food production more difficult. After nearly doubling from 139 million hectares in 1961 to 276 million hectares in 2002, the world’s irrigated area abruptly stopped growing. It seems peak water has arrived.


Industrialized Agriculture relies on Nitrogen-based Fertilisers

Nitrogen-based fertilisers enabled the ‘Green Revolution’ that boosted global food production in the last century, but that benefit came at a cost which we are now going to pay for.

Fossil fuels are needed for the continued production of fertilisers. As those fossil fuels become more expensive or harder-to-obtain, the ready availability of fertilisers is likely to be affected.

Natural gas is a key feedstock (up to 90 percent of the total costs) in the manufacturing of nitrogen fertilizer for which there is no practical substitute… Nitrogen fertilizer prices tend to increase when gas prices increase. ~US GAO report: “Natural Gas: Domestic Nitrogen Fertilizer Production Depends on Natural Gas Availability and Prices”

Between 1950 and 1990, the world’s farmers raised grain yield per hectare by more than two percent a year, exceeding the growth of population. Since then, yield growth has slowed such that the demand from a growing population is rapidly converging with the available food supply.


Expensive Energy = Expensive Food

Here we are, supposedly recovering from the worst economic downturn since the Great Depression, and oil is still trading at more than $80 a barrel. If and when a true recovery gets under way, that price is likely to rise even more, as I discussed in last week’s post on The Economy and Oil. This issue is critical, because our industrialised agricultural system is so reliant on cheap oil for harvesting, processing and transporting food vast distances to the store shelves.

10 kcalories of exosomatic energy are spent in the U.S. food system per calorie of food eaten by the consumer. Put another way, the (US) food system consumes ten times more energy than it provides to society in food energy. ~The Tightening Conflict: Population, Energy Use, and the Ecology of Agriculture”

Oil is a finite, natural resource and we are fast approaching the end of cheap oil. When oil is more expensive, food is more expensive too.


Climate Change

Whether you believe in human-caused climate change or not, it’s clear to most people that something is up with the weather. Many agricultural regions around the world are experiencing stronger heat waves, more drought or more extreme rainfall. It’s starting to affect the harvests we are relying on to keep us all fed. Droughts aren’t good for crops, but neither are record wet spells. Extremely wet conditions in the U.S. Midwest last fall delayed harvests to the point that some 30 per cent of North Dakota’s corn remained in the fields by the time a Christmas blizzard put an end to harvest time completely.

Agriculture as it exists today was shaped by a climate system that has remained remarkably stable over farming’s 11,000-year history. Since crops were developed to maximize yields in this long-standing climate regime, climate change means agriculture will be increasingly out of sync with its natural environment.

Population Growth and Food Scarcity

And finally there’s still population growth to consider.

World food production must increase by 70 percent by 2050, to nourish a human population then likely to be 9.1 billion ~UN Food and Agriculture Organisation

It appears that crop yields are moving closer to the inherent limits of the Earth. This limit establishes the upper bounds of the earth’s human carrying capacity. The question is not whether the world grain harvest will continue to expand, but will it expand fast enough to keep pace with rapidly growing demand? If we continue down the current path it is not likely to do so, which means that food supplies will tighten further. There is a real risk that we could soon face civilization-threatening food shortages.

Geo-Political issues

It’s easy to dismiss this issue as something that will only affect poor nations, but we now live in a truly global world. There are many ways that food scarcity can become very political and start impacting our lives in ways we never imagined. Since that’s a huge topic in its own right, I might leave that topic to another week.

This post is part of my World-Changing Wednesday series. Tune in each Wednesday to read my thoughts on an issue which I think will have a huge impact on how we live our lives in the years to come.


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