Agriculture – Part 6: The Impact of Human Population Growth on Food Production in the 21st Century

How much of the world’s land surface do we use today for planting crops? If I said 20% would you think that is too low. Well it’s not. There are conflicting numbers on just how much of the planet is under cultivation. Here are  interesting numbers from one source:

  • 81.98% of the land surface of our planet is of no value for growing crops (think the permafrost regions of Siberia,  Canada, and Alaska, the glaciated landmasses of Greenland, Iceland and Antarctica, the mountainous areas of the planet and the deserts)
  • 13.31% is considered arable
  • 40%  of that area is rated seriously degraded from over planting, erosion, salinization and desertification
  • 4.71% of the land surface of our planet is cultivated to produce food

Another source quotes the numbers as follows:

  • 11% of the land surface is cropland
  • 27% is pastureland
  • 32% is forested
  • 9% is urban
  • 21% is unsuitable for crops, pasture or forest

Why the discrepancy? It’s all about definitions. But the most telling statistic is the small percentage in either source devoted to agricultural production – between 4.71 and 11%. On that small amount of land we feed all of humanity and all of our domestic livestock.

Welcome to the Anthropocene

From 1 billion people in 1800, 1.6 billion in 1900, 6.5 billion in 2000, over 7 billion in 2011, and 9.5 billion projected by 2050, human population growth and our exploitation of the planet has led geologists to classify a new period of time called the Anthropocene. The Anthropocene depicts a stage in the planet’s geological evolution where human activity has started to alter the geomorphological features of the planet surface, the plant life, and ocean and atmospheric chemistry. No greater impactor exists than human population growth, outpacing mining and fossil fuel extraction, deforestation, damming of rivers, water and air pollution, and hyper-urban development.

Humanity has impacted Geology with the dawn of the Anthropocene

To feed our growing population we have reinvented agriculture turning us from gatherers of wild plants into  industrial agrarians. What Thomas Malthus theorized in 1798, that population growth would surpass food supply, has yet to come true because of agricultural intensification allowing humanity to feed its growing brood.

With human population growth continuing and finite land resources for creating food, what is the outlook for the 21st century? Will technology make it possible to continue sustaining people in the Developed World while solving the nutritional needs of those in the Developing World? Or will we reach a limit and witness conflicts for food and land based on the basic need to survive?

The following two scenarios paint very different pictures of our near future.

The Positive View – We Have the Capacity to Meet the Need

In the UN Food and Agriculture Organization report, “World Agriculture 2030,” Malthusian predictions are not anticipated. With a projected world population of 8.3 billion, the report describes a rosy picture of an increasingly well-fed population with 3,050 kilo-calories on average per day available to all people compared to 2,360 in 1960. Even in the Developing World the report forecasts an average of 3,000 kcal in consumption, well above the minimum daily requirement to sustain human life. The report forecasts that the number of hungry people will decline from 777 million today to 440 million by 2030.

Some highlights of the UN FAO report follow:

  • Meat consumption is rising in the Developing World from 10 kg per person annually in the mid 1960s to 26 kg in 1999.
  • Meat consumption is expected to rise to 37 kg per person annually by 2030
  • Milk and dairy has seen a similar rise from 28 kg in the mid 1960s to 45 kg in 1999
  • Milk and dairy is expected to rise to 68 kg by 2030
  • An extra 1 billion tons of cereal crops will be needed to feed the world population by 2030
  • Much of that increase will go to the Developing World which will increasingly rely on imported food to meet its population growth
  • Argentina, Australia, Canada, the European Union and the United States will remain the  largest exporters of food products
  • 70% of the food production increase will come from higher yields
  • 20% of it will come from increasing the amount of land devoted to agricultural production
  • 10% of it will come from multi-crop plantings and shorter fallowing
  • Expansion of farmland will increase by 120 million hectares (close to 300 million acres)
  • Most of this expansion will come from deforestation in the Developing World
  • Irrigation will expand in the Developing World from 202 million hectares (495 million acres) in 1999 to 242 million (close to 600 million acres) by 2030
  • This means a 14% increase in agricultural freshwater usage in the Developing World
  • 1 in 5 countries will suffer from a lack of adequate freshwater capacity
  • Genetically modified and bio-engineered plants and animals will play a significant role in ensuring food production increases
  • Modifications to crops will allow farmers to plant in marginal and degraded land areas currently considered unsuitable for food production
  • Water and soil conservation techniques in the Developing World will dramatically improve
  • Bio-engineering of crops will limit the impact on yields from  insect pests and weeds who will also under genetic manipulation
  • Free-range dairy and livestock herds will increasingly be replaced by industrial animal husbandry processes in the Developing World
  • Aquaculture will become a much more significant source of fish globally with most wild marine stocks depleted to unsustainable levels.

The summary report concludes that climate change may alter these projections hitting the Developing World harder. It states that small-scale farmers are most likely to feel the impact from prolonged drought, increased flooding and extreme weather events, salt water intrusions into groundwater sources and rising sea levels.

The Negative View – We are Heading for a Malthusian Meltdown

To counter the eternal optimism of the UN FAO, there is considerable evidence to suggest an alternate scenario. Worldwatch, an organization dedicated to creating an environmentally sustainable planet has its own set of facts. It reports some of the statistics that don’t appear in the UN FAO’s glowing predictions about the future:

  • The UN FAO’s own statistics show a decline in cereal food production per capita since 1984 even though yields per hectare have increased in both the Developed and Developing World
  • Rates of grain yield increases of 3% between 1950 and 1980 have declined to 1% since 1980
  • The World Health Organization estimates more than 3 billion people today suffer from malnutrition
  • In 1960 there was 0.5 hectares (approximately 1.2 acres) of arable land for every human being
  • Today there is about 0.23 hectares ( approximately 0.75 acres) per human
  • In the United States over the last 30 years, arable land  per capita has shrunk to 0.5 hectares (1.2 acres)
  • In the last 25 years arable land per capita in China has declined from 0.11 hectares (approximately .25 acres)  to 0.08 hectares (0.2 acres)
  • Per capita cropland decline is exacerbated globally  by the abandonment of 10 million hectares (24 million acres)  each year because of soil degradation and erosion
  • Add to that 10 million more hectares (24 million) lost annually from salt buildup in soils because of poor irrigation and drainage techniques
  • 60% of deforestation annually can be attributed to human efforts to replace lost cropland
  • Cropland soil erosion rates range from 10 metric tons per hectare per year in the United States to 40 tons per hectare in China
  • In the past 30 years soil loss in Africa has increased by a factor of 20
  • In the past 30 years irrigation has contributed to dropping groundwater levels of  25-30 meters (80-100 feet) in Southern India
  • In Beijing, China, irrigation and urban usage is causing groundwater levels to drop at a rate of 1 meter (3.25 feet) per year; In Tianjin, China, that rate is 4.4 meters (close to 15 feet)  per year
  • The United States is pumping irrigation water out of the Ogallala Aquifer, the groundwater repository under the Great Plains, at a rate three times faster than it naturally can be replaced

Conclusion – The Outcome is Doubtful Based on the Way We Practice Agriculture Today

So is everything going to be OK as the UN FAO forecasts? Or are we facing an unsustainable future of  doom and gloom as Worldwatch would suggest? How much can our technological inventiveness overcome the challenges of finite land, finite freshwater, rising human population, and rising consumption?

There is an interesting website called World Population Awareness. It features a counter displaying running totals for a range of statistics:

  • The number of people born since coming to the website (2.8 people per second)
  • The number of people who died from hunger (.2778 people per second)
  • The number of acres of wild lands lost (1.6 acres/0.65 hectares per second)
  • The amount of CO2 emitted (708 metric tons per second)
  • The amount of topsoil eroded from farmland (747.5 metric tons per second)

These are disturbing numbers because they just continue to mount up the longer you are on the site.

The word sustainability has become part of our lexicon these days. Everything good is green and sustainable. We talk about a sustainable economy, sustainable job creation, environmental sustainability. Sustainability requires investment and the investment is not just money. It also involves an investment of commitment on the part of the global community.

In the story “The Lady or the Tiger” the dilemma for a condemned man was to make a choice of opening one of two doors. Behind one lurked a tiger that would surely devour him. Behind the other was a lady who he would wed. He had no way of knowing ahead of time which outcome he would face.

We do and we have the means to change the outcome. But more on that in a future blog.


Len Rosen lives in Toronto, Ontario, Canada. He is a researcher and writer who has a fascination with science and technology. He is married with a daughter who works in radio, and a miniature red poodle who is his daily companion on walks of discovery. More...