Your Green House

Activity Flow

1. Cut a big, rectangular hole in the lid of the box. Leave enough margin so your greenhouse has some stability and there is space enough to fix the wrapping film.
2. Close the hole with wrapping film, glueing or sticking it to the lid of the box.
3. If you like, you can repeat the same procedure with the sides of the box.
4. Place one of the thermometers inside the box, so that you can see the temperature through the film.
5. Put the box into the sun. Try to have the temperature sensor of the thermometer is in the shadow (so it measures the air temperature and not the direct insolation).
6. After 1 or 2 hours, you can compare the temperatures inside the box and outside (with the second thermometer, also in the shadow)
7. If you have more time, you can also grow plants: one inside the greenhouse, one outside. After one week, what difference do you observe?
8. Answer to the following questions, according to your age group:

Level 1 (5-10 years):

• What do you observe?
• How do the plants grow?
• What difference can you observe between the temperature inside and outside the greenhouse?

Level 2 (11-14 years):

• Draw a picture of how a gardeners greenhouse (like the one you’ve built) works. Indicate the sunrays and the heat rays with arrows.
• Compare the greenhouse of a gardener with the ‘greenhouse’ of the earth. What is the earth’s ‘greenhouse’ made of?
• Why is this ‘greenhouse’ of the earth so important for us?

Level 3 (15 years and older):

• Discuss how the greenhouse effect of the earth’s atmosphere functions.
• Which are the greenhouse gases and how do they influence the greenhouse effect?

• Which factors are responsible for climate change? 

   

Theory

What we call global warming is a relatively recent phenomenon. Over the last few decades, the surface temperature of the earth has been rising year after year. This rise in temperature is directly connected to the fact that the greenhouse effect has become unbalanced.

Life on earth is only possible because of the earth’s atmosphere, a layered mix of gases that envelopes the planet. The rays of the sun easily penetrate the atmosphere. Sunlight is absorbed by the earth and transformed into heat. However, instead of escaping through the atmosphere, some of the heat radiating off the earth is trapped by greenhouse gases and reflected back to the surface. This feedback mechanism heats up the planet even more.

Without the atmosphere (and the “greenhouse” it creates), the average temperature on earth would be -18°C/-0.4°F (instead of ca. 14°C/57.2°F). The most important of the greenhouse gases is water vapour, the second most is CO2 (carbon dioxide). The latter’s high emissions mainly due to burning fossil fuels (for transport, heating, industry and power generation) changes the composition of the atmosphere, which leads to higher and higher temperatures on earth. 

Let’s get things clear: Not the greenhouse effect itself is a problem for mankind, but the fact that the effect's equilibrium is getting out of control. 

If you try out the growing of plants inside and outside the greenhouse, make sure that the plants get enough water.