Global worming (the lesson)
Read the text ‘global worming’ and answer the questions. If possible do the experiment.
1. Why are people worried about the CO2 in the atmosphere
2. What are the causes of the rising of the CO2 in recent times? (give 3 causes)
3. Worms in the soil are good for soil quality. Give 3 reasons why.
4. Why did some farmers stop ploughing the fields before planting? (in other words: what is the sense of ploughing, and what is making it sometimes better not to do it?
5. In Northern America the earthworm went extinct during the last Ice Age, in Europe they survived. Only after immigrants from Europe brought planting material to America the earthworm returned, but it is spreading very slowly across the continent. Where this happened the fertility of the soil was improved, because worms convert a lot of organic matter. Forests can grow more new wood with enough worms underground. Which other changes in the ecosystem do you expect to occur after introduction of the worms?
6. People could conclude from this result that it is better to kill the worms. But the scientists do not want that. In fact it is even possible that in the end the production of CO2 is lower where the worms live because of more plant growth. Describe an experiment with which scientists can find out if this is the case.
7. You can also design an experiment with which you can measure this yourself. Make a working plan – and if possible do the experiment in your class