The Carbon Cycle uses an equilibration model to show how once fossil carbon is released into the air, it migrates into various carbon sinks - atmosphere, terrestrial plants, soil, ocean surface, and deep ocean. Explores changes in fossil fuel usage, net deforestation, and melting tundra.
Demographics explores population growth pyramids, much like my earlier Human Demographics simulator, where you can change birth and death rate schedules. In this rendition, the user can set vital rates to match those of a different country. (E.g., how would India's population develop under US birthrates.) Countries: USA, China, Egypt, India, Italy, Mexico, and Nigeria.
Disease demonstrates contagious disease spread through a population. Three diseases (Kold, Impfluenza, and Red Death) are supplied, and the user can create variations with different incubation, deathrate, etc. parameters. Explores the effects of population density, population mixing, vaccination strategies, and pitting one virus against another.