Populations

Food production must keep up with demand and changing tastes. As global populations increase and economics change, the need for higher protein sources becomes critical. This unit discusses population demographics and the effects on global food production.

Unit level:

High school

Phenomenon

Students begin to develop a sense for the Earth’s carrying capacity and how humans have impacted it.

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Population growth

How quickly has population increased over human history? What might help slow the rate of increase?

What do students do? Students analyze and interpret data to see how quickly population increases.

What do students figure out? Resource availability does not seem to limit the growth of human populations in the same way as other organisms.

HS-LS2-1

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Population age structures

What is an age structure diagram? How does age structure affect population growth? Why is this important in food production?

What do students do? Students analyze age structure diagrams from various countries.

What do students figure out? Population grows fastest in areas of the world that have the fewest resources or infrastructure.

HS-LS2-2

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Demographic transition

What demographics change as economies develop? How does demographic transition affect the kinds of foods and resources demanded?

What do students do? Students research land and water use as well as other factors to create a spreadsheet that illustrates the relationships between human populations and the sustainability of human populations.

What do students figure out? Countries change over time through economic development. Those changes have an effect on how people work, live, and eat.

HS-ESS3-3

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Exponential versus linear growth

How fast has the human population grown compared to corn/soybean yield? How might we map these rates into a mathematical model or equation?

What do students do? Students use data sets to compare crop yield to human population growth.

What do students figure out? Technological advances and events may impact the growth of yield and population growth.

HS-LS2-2

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Farming for the future

How many people farm in the world? What are the practices that the majority of global farmers use?

What do students do? Students engage in a subsistence farming simulation. Upon completion of the simulation, students evaluate and refine solutions for addressing problems encountered using these methods.

What do students figure out? People who rely on subsistence farming are taking chances on weather, the types of crops to plant, and the limits of yield. Education, infrastructure, and health care may be lacking in many of these countries.

HS-LS2-7

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Teacher background

According to most estimates, there will be over nine billion people on the planet in 2050. Many experts suggest that growers will have to produce more food in the next 50 years than has been grown in the past 10,000, which is doubling current production on the same amount of land. Yield increases have begun to slow for both corn and soybeans (see USDA graphs: corn and soybean.) Therefore, this demand will require the development of new technologies, new techniques, and new environmental practices.

What are the limits to food production possibilities? The amount of arable land may decrease if climates continue to change. Water is limited around the world and the places that are most productive are not necessarily in the areas where food is most needed. Fossil fuels, even with the addition of ethanol, are necessary to run tractors, while fertilizers and pesticides are also energy intensive to create. Therefore, food production is closely tied to fuel costs and availability. Another concern is the infrastructure that is necessary to get food to markets before it spoils. In many less economically-developed countries, there is no system to get the food to market and storing it is not a viable option due to fungus and pests destroying it. Soil is also vulnerable to erosion, desertification (once fertile land becomes arid), salinization (build-up of salts in the soil from over-irrigation), and water-logging (saturation of soil by groundwater).

One of the largest problems in the developed world is food waste. Some of the crop is lost in the field to pests (about 30%), some is left during the harvest (10–20%), and in the U.S., it is estimated that consumers throw away as much as 40% of their food. Population pressures are driving today’s food production demand. While the need to feed a growing population will continue, factors such as decreasing infant mortality rates, a reduced need for children to work, increased educational opportunities for women, and access to family planning will improve the standard of living in countries worldwide and increase the demand for food. With 9+ billion eaters, the agriculture industry, made up of large-scale farmers, local food producers, entrepreneurs, ag scientists, and engineers will all become allies in meeting future food demands.