"Lab-in the kitchen" exercise:
- Are gases soluble in water?
Find a flask, add some water, heat the water and observe.
Explain where the bubbles come from
Try to formulate a rule for what you see. e.g. can you draw some conclusion on the capability of water to retain a gas under varying temperatures?
How does this relate to the Greenhouse effect?
- Adjustment time
A big and complex system in balance can be destabilized by relatively small factors if these are accumulative and take place over time. Example: if there is a 4% annual accumulation, the original volume will have doubled in 16 years. With a 5% annual increase, the volume will have doubled in ten years.
Demonstrate this in a "lab-in-the-kitchen" exercise:
Put the plug upside down in the outlet of a washbasin.
Draw a short line on the side of the washbasin with a waterproof marker.
Open the cold-water tap and fill up to the mark.
Adjust the water-flow so the same amount of water runs in as runs out, keeping the water-level exactly on your line.
Let it run a minute or two to ensure that you have equilibrium.
You now have a system in balance.
This system can function as a dynamic picture of the CO2 in the atmosphere (the water in the basin), the flow of CO2 from nature to atmosphere (water from the tap) and the flow of CO2 from the atmosphere back to the ecosphere, ocean etc. (water going out the drain - the sink).
Take a big plastic bag.
Fill it with water; hold it over the basin while making a small hole with a knitting pin.
Even if the water coming from this plastic bag is relatively insignificant, you will probably notice that the water level increases.
This extra water symbolises the human-made emissions of greenhouse gases.
When you stop adding the extra water, the water level will gradually go down until it reaches its old mark - or the equilibrium.
The time needed to revert to the equilibrium is the adjustment time.
How long time the extra water molecule stays in the basin is of little interest.
The interesting question is the adjustment time.