This lab uses a robust model of the carbon cycle to give you an intuitive sense for how carbon circulates through the atmosphere, biosphere, oceans, and crust. This model is similar to ones presented by the Intergovernmental Panel on Climate Change. It allows you to experiment with how human input to the cycle might change global outcomes to the year 2100 and beyond. One particularly relevant human impact is the increase in atmospheric CO2 levels. Between the years 1850 and 2006, atmospheric concentrations have risen from 290 parts per million (ppm) to over 380 ppm - a level higher than any known on Earth in more than 30 million years (see Unit 12 to find out how scientists measure ancient atmospheric carbon levels). Using the simulator, you will experiment with the human factors that contribute to this rise and explore how different inputs to the carbon cycle might affect the concentrations of the greenhouse gas CO2.