Introduce the concept of modeling and simulation.
You have [The Forest] of 1 million trees and are concerned about the long term sustainability of the forest. The lumber company has ensured you that they will only cut 1,000 trees a year and they will faithfully plant a new tree for every tree they cut down. Under this agreement will [The Forest] be sustainable?
For the next 10 years things seem look fine though does that situation continue into the long term future?
When we run the model for 20 years there seems to be a trend in [Mature Trees] that warrants concern.
Looking at the situation over a longer period of time shows a boom and bust cycle that seems to occur on a 20 year cycle. What's up with this?
As the lumber company cuts trees and makes money the business becomes more and more attractive, so the lumber company develops its capacity to cut more trees. This results in the Attractiveness Reinforcing Loop (R1). While this is happening the [Attractiveness] decreases as the ratio of [New Trees] to [Mature Trees] increases.
The lumber company has agreed to plant [New Trees] for every one they are cut down creating a the Forest Maint Balancing Loop (B2). The problem is that the lumber company cuts down [Mature Trees] and the [New Trees] they plant take 20 years to mature. This means that if they cut down trees too rapidly the maturity of the forest can rapidly decline.
How did things get off track from the original agreement? As the logging company made more money they paid you more money, and convinced you things were fine. And the more money they paid you, the more you believed them. The number of trees cut on an annual basis simply continued to increase until the forest wasn't sustainable.
The question is, how do you alter the relations so [The Forest] is sustainable? We don't expect you can do this now though through the experience and skill you will develop from the interactive learning experience to follow, you will!
You can alter the sliders in the Configuration Panel and Run Simulation to get a better sense of the implications of the interactions.