Enhanced Greenhouse Effect.
Experiment to demonstrate the Greenhouse Effect
Beginning with a short introduction / recap of the greenhouse effect, this simple experiment illustrates the principles of the greenhouse effect. Heating beakers of gases using sunlight or even bright lamps shows the different properties of the gases. Students can obtain surprisingly good results on a sunny day. There is also a set of sample results, just in case it rains, and the lesson could be a data analysis opportunity.
Which gases are greenhouse gases?
What type of radiation do they absorb?
Is it possible to see this effect in the lab?
Activity 1 Introduction to the Greenhouse Effect
What is the greenhouse effect and how is it warming the earth?
Activity 2: Experiment to demonstrate the greenhouse effect in the lab
Carry out the experiment on the Greenhouse Effect Experiment worksheet below.
Does the data you collect support the idea of the greenhouse effect?
Activity 3: Extend the experiment
If you have time try repeating the experiment using methane gas from the gas taps or exhaled air. Both of these are rich in greenhouse gases. (Beware: evaporation and condensation of water vapour in exhaled air cause temp. changes too.)
There are a few alternative ways to do this experiment.
Here are a few suggestions:
- Use data logging probes which work well if you can take them into the sunshine.
- Use large conical flasks and bungs with thermometers fitted. This keeps the gases in place much better than beakers. Turning the conical flasks upside down would make it possible to balance the petri-dish of water on top, to absorb infra red radiation from the lamp or the sun. Retort stands could be used to hold the conical flasks in place.
- When trying exhaled air the results don't work very well on a cold day. I think this may be to do with faster heat loss, or else energy changes caused by water vapour condensing and then evaporating again.
*** This lesson should also have mention of the shortwavea and longwave radiation and ho greenhouse gases absorb and release it. ***
Follow the four exercises on this great animation from the Norwegian Centre for Science Education. Simple introductory animation about the greenhouse effect