Carbon dioxide is the most abundant greenhouse gas in the atmosphere. Carbon dioxide levels in the atmosphere are largely determined by the release of carbon from the burning of fossil fuels and the uptake of carbon dioxide by vegetation (during photosynthesis). Carbon can also be stored in the soil and in the ocean (representing the largest pool of carbon on Earth). Although levels of carbon dioxide in the atmosphere have fluctuated throughout the history of the world, we are currently seeing the highest levels ever known.
Go to http://www.learner.org/courses/envsci/interactives/carbon/index.php and click on “open simulator” in the upper right corner. This will open a new window for the Carbon Cycle simulator that you will use in this activity.
In this simulation, you will experiment with how changes in fossil fuel consumption and rates of deforestation affect the concentration of atmospheric carbon dioxide, as measured in parts per million (ppm).
Using the simulator
The default settings for this simulator represent our current increase in fossil fuel use each year—2% (each year we use 2% more fossil fuels than the previous year) and our current annual deforestation rate—1 global ton (G.T.) per year. You can adjust these rates by moving the slider to the left or right. You can also click on “None!” to see what would happen if we stopped using fossil fuels altogether (-100%). Click “reset” to adjust the rates and then click on “run decade” to see how atmospheric carbon dioxide will increase each decade at the given rates. You can see exact numbers by hovering over the graph line.