Models of global warming can be used to predict how much the Earth will warm under different greenhouse gas emission scenarios. For this assignment, you will read some background material and operate a Greenhouse Gas Emissions Simulator written by a research group at MIT. First, read the recent New York Times piece by Andrew Revkin at http://dotearth.blogs.nytimes.com/2009/01/28/the-greenhouse-effect-and-the-bathtub-effect/?_r=0
You do not need to follow the links or watch the video unless you are interested and want more information.
After reading the New York Times piece, you can watch the global warming bathtub effect in action by going to the Greenhouse Gas Emissions simulator at http://scripts.mit.edu/~jsterman/Management_Flight_Simulators_(MFS).html
Go to the link for Greenhouse Gas Emissions Simulator (New). Read the text that accompanies the simulator and then try some of the simulator scenarios. As you go through the different challenges and experiments, answer the following questions:
Challenge 1:
You do not need to do this part so skip to Experiment 1 at the bottom of the page.
Experiment 1:
Try to find a value of emissions that brings the CO2 level close to the target level by 2100. Do this for the three outflow scenarios and observe how the outflow changes for each. What value of input brings CO2 close to the goal in 2100 when the outflow scenario is positive feedback?
What value must emissions be kept at to keep the green curve (net removal) from dropping over time under the positive feedback outflow scenario?
Experiment 2:
You can see that as population growth and improved standard of living are factored in, things become even more complicated. Explore various scenarios and see if you can find settings that keep the Earth from rising above the goal CO2 concentration of 500 ppm.
Please write down the inputs you found for one scenario that keeps CO2 at or below 500 ppm.As you do all of these exercises, recall that 500 ppm is thought to be a maximum concentration of CO2 that will keep the Earth approximately as we know it today. Higher values could have unforeseen consequences. Note also that the current global emissions of carbon dioxide are about 6.2 gigatons/year (4.1 GT/Y if it assumes that the ocean, soils, etc. will continue absorbing some of the excess). Keep these numbers in mind as you try to meet the target levels in the exercises and think about how your numbers compare with those needed to keep the world from overheating.