Bathtub Model

The bathtub model can be used to explain the climate and different futures. I personally like this model because it is easy to understand and the concept allows you to play with different situations in order to determine the outcome. For example, the first tub that was shown was a tub at an equilibrium state. In this state the amount of water being put in the tub is the same amount that is leaving the tub. This allows the water in the tub to stay at a constant level. Comparing this to the environment, if humans were not on this planet, the atmosphere would be at an equilibrium due to the natural processes on Earth. Another situation that can occur for Earth is that more carbon dioxide being put into the atmosphere than it is being taken out. This would mean turning up the faucet on the bathtub. This would cause the tub to over fill. This simulates when humans began using machines and producing carbon dioxide, putting more in than the natural amount. The opposite could also occur, where more carbon dioxide is being taken out than is being put in. The additional amount of carbon dioxide being added by humans can also be shown in this model by adding a second faucet. This would show that carbon dioxide is being put into the atmosphere by multiple sources. Some plants and oceans are partially absorbing some of the extra CO2, which can be represented by more holes on the bottom or  larger hole. Additional bath tubs can be added to the circuit in order to represent other parts of the carbon cycle. You can then change the input and output of the water in the tub in order to coordinate it with the emissions. This is a nice representation of the Earth's atmosphere and the multiple influences that cause it to warm up or cool down. This can be used to predict or visualize the future outcomes if we lower our emissions, keep them the same or even make them greater.