Food production, Population growth and GMOs
Grade level(s):High School (9-12), Grade 9, Grade 10, Grade 11, Grade 12
Topic:Intro lesson to genetically modified organisms and their uses
The human population is reaching 7 billion in 2011 and possibly 9 billion by 2050. The poor management of natural resources is creating a global food crisis. One of the many possible solutions to the current food crisis is the controversial use of genetically modified organisms (GMOs) in agriculture.
food chain, energy pyramid, population growth rate, limiting factors, natural resources, deoxyribonucleic acid (DNA), central dogma, climate change
What you need:
Internet connection to stream National Geographic "World Food Crisis" video (see lesson for link).
Print out all data sets.
Post its or notebooks - for students to write down and organize their thoughts in each page of data
Slides provided - link data analyzed to previously learned standards.
Small groups of three for data analysis. We would NOT recommend larger groups as this will not allow enough time for each student to contribute with ideas for their group. If necessary it can be groups of two as there will be another group looking the same data set and between the two groups most points would be brought up.
When going through each data set make sure to engage the rest of the class by asking questions to the whole class about the data and what was presented by other groups.
Lesson 1 - Regular classroom
Lesson 1 - 1 1/2 hours
This interactive lesson is part of a lesson series (3 total) that focuses on topic of genetically modified organisms (GMOs). The first lesson focuses on agriculture, food production, natural resources and population growth. The second lesson focuses on GMOs and their possible uses in agriculture as a way to fight world hunger and diminishing resources (this could be a very controversial issue and a great way to get students engaged in their learning). For the final lesson students are asked to (a) research the pros and cons of the use of GMOs in agriculture (b) propose other possible sustainable solutions to the current food crisis (c) propose individual behavioral changes in our daily lives or community solutions to protect our natural resources and avoid a more catastrophic food crisis.
The goal of the first lesson is to get students engaged in current global issues while learning and brainstorming about possible solutions. In this lesson the students are asked to look at data sets from multiple sources and summarize the main points by presenting them to the rest of the class. Student presentations promote discussion between students and help to integrate previously learned concepts such as the food chain, energy pyramid, water cycle, water footprint, flowering plants and agriculture. Additionally, students are introduced to new concepts such as population growth and limited natural resources.
Throughout the presentations the teacher guides the students to draw conclusions and helps them make connections with current world issues. After going through the data, there is a brief presentation on the historical timeline of the development of agriculture. The presentation also introduces the industrial revolution and agriculture's green revolution and their effects on human population growth. Overall, this lesson plan is an introduction to the use of GMOs in agriculture as one of the possible solutions to the current food crisis.
Before beginning this lesson plan students should have a general knowledge of the following concepts:
- Central dogma of biology
- Population growth rate and limiting factors
- Food chain and energy pyramid
- Climate change
- Understand the impact of poorly managed natural resources
- Analyze sets of data (population growth and use of natural resources) and draw conclusions from these data sets
- Identify possible solutions for the current food crisis
As a background for this set of lessons (especially lesson 1) we propose the following articles:
- National Geographic, 7 billion: http://ngm.nationalgeographic.com/2011/01/seven-billion/kunzig-text
- The Economist, The 9 billion people question (special report on feeding the world): http://www.economist.com/node/18200618
- National Geographic, Water Special Issue: http://environment.nationalgeographic.com/environment/freshwater
- National Geographic, Our Good Earth (Issue on soils): http://ngm.nationalgeographic.com/2008/09/soil/mann-text
- Print out all data sets and laminate them so you can use them again later.
- The National Geographic "World Food Crisis" video should be buffered completely before showing it if your internet connection at school is too slow or if internet access is lacking in your classroom.
Lesson Implementation / Outline
Introduce the current world population numbers and show the National Geographic video on world food crisis. Also show students newspaper clippings with local news that talk about the increase in food prices to make a connection to the local impact of these issues. See attached slides ("lesson_1_no_data.ppt").
ASK: What comes to mind when you think of "world population"? What comes to mind when you think of "Natural resources"? Write down student responses on the board.
Make a "Know, Want to know, Learned chart" (KWL chart). Write on the K chart the words that students shared both for "Human population" and "natural resources" (This is a good way to see what they already know, what interests them and what misconceptions they might have).
ASK: What else do they Want to know about world population and natural resources. (Fill in the KWL chart)
DATA ANALYSIS ACTIVITY
Ask students to sit together in groups of three. Distribute sets of data to students. There are four different data sets. (See attachments for data set 1-4)
- There should be one data set per group.
- Each student should have their own copy of the data set.
- If possible there should be two groups of three students per data set.
Think-pair-share: Ask students to look at the data individually and write down interesting points they noticed in the data. After they should share it with their group and discuss which ones they think are the most important/interesting points to share with the rest of the class. Give the following instructions to the groups:
- THINK - (individually): use post-its to write down interesting/surprising things that you notice about each data (3 min)
- PAIR - (Group): Share what you find with your group (3 min = 1 min per student)
- SHARE - (Group): As a group discuss and write down 3 points of your data that you think are important to share with the rest of the class (3 mins)
Class share: Go through each data set separately. Starting with Data Set 1 ask the two different groups to explain to the class what their data shows and to tell the class three main points they noticed in the data. Write on the board what the students learned from their data set.
DATA SET 1 - ANALYSIS
(Crop yields, population growth, food prices and global food demand) - see attached PPT file "data_set_1.ppt"
- How have crop yields, food prices and diet been changing through the years? (Have groups to present the main points of the data to the rest of the class)
- Food prices were high in 2008 (when the video was made) and are peaking again in 2011.
- We are not producing food at the same rates we used to (maize, rice, wheat crop yields are decreasing) but demand for food keeps increasing (world population keeps growing; consumption of meat is increasing most rapidly).
- Crop yields are decreasing (Ask students: why do you think that is? Possibly due to bad management of resources such as soil; climate change – extreme periods of drought... etc.)
- More people are eating meat (Ask students: why is this? the middle class is expanding worldwide and cultures are changing their eating habits; ask students: how does more people eating meat impacts crop production? Link to food chain and energy pyramid – if more people eat meat there needs to be more crops produced to sustain the increase in meat consumption; More grain is needed to produce a meal with meat than a meal with grain products due the inefficient energy transfer in the food chain) – see slides
DATA SET 2 - ANALYSIS
(World’s fertile soil distribution, main crop producers by country, drought) - see attached PPT file "data_set_2.ppt"
- Fertile Soils Data: Do we have a lot of fertile soils? Where are they located?
- Crop Production and Drought Data: Where is it happening?
(Have groups to present the main points of the data to the rest of the class)
- Of all the land in the world, a very small percentage has highly fertile soil. The rest of the world needs to make due with soil that’s “just ok” for growing crops and thus doesn't produce high, consistent yields.
- Only a few countries are responsible for the majority of the world’s food (China, US, India). If something were to happen in these countries (drought, other catastrophe) it would have dire consequences for the rest of the world’s food access.
- The same regions (the US, China, Argentina) that had fertile soil and thus produce the majority of the world’s crops are also susceptible to drought.
- Climate change which results in the change of weather patterns will make crop yields even less reliable.
DATA SET 3 - ANALYSIS
(Human water footprint) - see attached PPT file "data_set_3.ppt"
- Water is an essential natural resource without which life would not occur.
- Water footprint is the water used for personal consumption and for the production of goods and services.
- Of all water on Earth what fraction is readily available for human use and consumption?
- Which countries have the highest water footprints?
- Which human activities consume more water?
(Have groups present the main points of the data to the rest of the class)
- Majority of the world’s water is inaccessible/not drinkable/unusable (only a very small percentage of the planet’s water is readily available for human consumption – the rest of the water is stored in icecaps or is in the form of seawater.
- 70% of all freshwater is used for agriculture only!!!
- The higher you go up the food chain and the more processed foods are, the more water is required to produce them.
- Americans are the highest consumers of water
Water is essential for our survival. Still due to poor management of our water resources and to pollution the levels of usable water are decreasing at a alarming rate.
- How do you think that could affect the production of food?
(Show news slide – groundwater depletion raises likelihood of global food crisis)
DATA SET 4 - ANALYSIS
(World population growth and consumption) - see attached PPT file "data_set_4.ppt"
World Population and Consumption:
- Which countries have the bigger populations?
- Which countries have grown more in the last decades?
- Which countries show higher levels of consumption?
- How has consumption grown in the last decades?
- How does population size relates to consumption?
(Have groups present the main points of the data to the rest of the class. Make sure they explain how the data is being represented.)
Population (when you compare this world map with a physical world map you will notice…)
- India, China, Japan are all huge population-wise, relative to their real physical size.
- Countries like India, China, Brazil, parts of sub-Saharan Africa are growing most rapidly (white dots: black dots)
- Some countries (like many in Europe) are not experiencing any population growth.
Consumption (when you compare this world map with a physical world map you will notice…)
- For its size/population, the United States is the biggest consumer.
- Europe also a huge consumer
- For so massive a continent, Africa consumes almost nothing
- Japan also a huge consumer.
- Note the rate of change in consumption since 1980s for countries like the US, China, India (white dots : black dots)
United States and Europe are the biggest consumers of resources. China and India are growing rapidly both in their population and in their consumption levels.
- The rapid population growth aligned with the global food crisis and the increased use and mismanagement of resources is leaving a huge strain in the planet that can lead to unpredictable consequences.
- But how did we get to where we are today?
- infertile soils, freshwater depletion, diminished food resources? Let’s take a look at history. (See slides for images and more background information)
(1) Explain to students how major historical developments such as domestication of plants and animals, agriculture-based societies and industrialization allowed for an exponential human population growth due to unlimited food resources.
(2) 1960s – Agriculture “green revolution” – irrigation, selective breeding of crops that produce more “fruit”, development and use of synthetic fertilizers and chemical pesticides. These short-term solutions were great to increase crop yields but in the long term it has lead to the infertile soils, loss of biodiversity, pollution, salinization of soils(**) and mismanagement of water.
(3) Due to the green revolution, grain production has easily kept with demand until recently. For the last decade global consumption has become higher than global grain production.
(4) How are we going to address this worldwide problem? Left with less productive land what are possible solutions to the current food crisis?
World leaders, farmers and scientists have proposed some possible solutions. Some of which include, sustainable farming, better irrigation, better land and water management and possibly genetically modified organisms.
(**) Salinization of soils happens often in dry lands. The removal or trees for agriculture and the use of excess water for watering crops leads to the accumulation of salts in the soil top layer. Water naturally has salts - even rain has salts. In a soil planted with deep-rooted tress when it rains the water gets fully absorbed by the trees and other deep rooted vegetation. In the process of agriculture trees are cut down and substituted by annual crops that have shallow roots. This disrupts the water cycle. When it rains not all water gets absorbed by the plants and leaks to the water table. When you add excessive irrigation to this equation you can imagine that the water table levels rise due to the massive addition of water by irrigation and the absence of deep rooted plants to absorb it. Once the water table rises it brings more salts close to the surface which by capillary action will deposit in the top soil making the soil too salty and diminishing plant grow - this promotes desertification where the soils due to their high salt concentration are not permissive of plant growth.
In the next lesson (lesson 2) students are going to learn about genetically modified organisms (GMOs) and their potential applications in helping solve the current food crisis. Students are also going to look at different foods for the presence of GMOs using DNA extraction, PCR and gel electrophoresis.
In this first lesson, Think-Pair-Share and KWL charts are used to assess student's previous knowledge and to get them engaged in the topic being covered (see attached PPT slides). Students will present a summary of the information in their data sets to the class.
At the end of the lesson ask students to reflect on today's topic and to write down in an index card three things they learned in this lecture. Ask the students to get together in groups of two and share their reflections of what they have learned. Finally one of the students from each group share their reflections with the rest of the classroom. You can have the student which birthday is next to share from each group. Use these reflections to finish the KWL chart.