Home

History and/of the environment

Categorie(s): Ecology, Human history and the environment, thematic lessons

Slash and burn agriculture in Amazonian rainforest

It belongs to our time in history to be worried about environment, climate change, ‘plastic islands’ in the oceans, extreme weather, etc. Of course, never before so many people lived on this planet, never before people used so much fossil fuels, partly to make synthetic materials that cannot be broken down in natural systems.

But it is not new that humans have impact on their environment and the climate. There were never so many people as today, but people have never been very careful with their environment. In many places people would burn down a piece of forest, to make place for their agriculture. After a few years the soil would be depleted, so they did the same with the next piece of forest. Deforestation is very old. That we  link human activity and climate change, desertification, extinction of species – thàt is new!

On this site you can find several examples of historical environmental problems caused by local people. When catastrophes happened as a result of their activities people probably saw them as a ‘punishment from the gods’. Now we can explain the real cause. It is good to realise that we are still doing much damage by our way of  living, – but now we know it, and we have the possibility to do better and prevent more catastrophes.

In this lesson we look at Maya cities in Central America, Angkor Wat in Cambodja, Easter Island in the Pacific Ocean,  the more general effect of agriculture nearly from the beginning, and the relation between population density of hunter-gatherers and the ecology. 

For this lesson you can best devide the class in (4 or 8) small groups. Each group works on one of the stories, studies the text, answers the questions, and prepares a presentation about the case. And don’t forget to make a connection with our time! What must be done to prevent the same mistakes as people made hundreds or thousands of years before our time?

Maya cities

Questions:

1. The Maya’s had a highly developed culture that survived for many centuries. Find information about when and where exactly this culture blossomed. And about the culture itself.

2. The Maya’s had big cities with great temples. The ruins have been found deep in the rainforest. Big cities need a highly developed agriculture. Which crops did the Maya’s cultivate? What do people in that region eat today?

3. How is it possible that the thick layer of plaster on houses and temples is the cause of erosion?

4. On the hillsides they used terraces (comparable with the wet ricefields in southeast Asia). How does construction of terraces make agriculture more sustainable?

5. The temple ruins were found back in the rainforest. Scientists who know these forests can see the difference between real pristine forest and forest still recovering even after several centuries. Explain why complicated ecosystems need much time to recover after disturbance or even annihilation.

6. People often do things not because it is useful, but ‘because it is possible’ . In out society we can see plenty examples of this behaviour. Why drive a big 4-wheeldrive in the city? Find and describe more examples of useless consumption – and discuss the question: “ why do people do it?”.

7. More important : “How can you convince people not to do it anymore?”.

Your presentation: Tell the story of the Maya’s, the causes of the collapse of their culture and the lesson for us.

Easter Island

This text contains questions that you can use to prepare your presentation.

Compare the situation of the islanders with the situation of mankind today, isolated in space, with no possibility to evacuate the population (even if some people think we could move to Mars. Explain why this is nonsense!)

Angkor Wat

Questions:

1. The locals knew about the ruins of Angkor Wat, but they were ‘discovered’ by Europeans in 1860. Why did these Europeans think that the locals never could have built something like that?.

2. How can growing rice cause deforestation, erosion and loss of fertile soil?

3. Scientists think the cultivated area had grown too big, causing the collapse of Cambodjan civilisation. How could that happen?

4. Nowadays we have big scale agriculture all over the world feeding bilions of people. Why is  modern agriculture  not (yet) collapsing? What do we do better?

5. People are worried that the old buildings could collapse because too much water is being pumped from underground. The problems 1000 years ago must have been different. What must have caused the collapse?

6. The highly developed culture of Angkor Wat disappeared because of ecological factors. This has happened more often in World history. Why is this a warning for us today? Hou can you make this clear to people?

7. What can each of us do personally to help prevent the collapse of our civilisation

Early farmers

In the other cases you look at local situations, where the local people probably had a bad time, maybe starvation, wars , etc. In this case we look at the effects of agricultural methods of thousands of years, with consequences worldwide.

Questions:

1. What is ‘slash-and-burn’ exactly?

2. Why was it possible to use this method for thousands of years?

3. In the Philippines they had  it  organised so that a piece of land could be used again only after 10 years. This worked well for hundreds of years. But when the population grew it was decided to use a plot already again after 3 years. After that the system did not work anymore. How can you explain that?

4. Look carefully at the 2 graphics. What changed when agriculture started?

5. And what changed when the wet rice culture started?

6. Why do wet rice fields produce much methane?

7. The farmers of the world have prevented a new Ice Age. We must thank them for that! But why are we no longer happy about the rising of CO2 and methane in the atmosphere?