Scientists are interested in the rate of change, in other words, how fast the carbon dioxide (ppm) is increasing as the years go by.  In 1971, the globally averaged CO2 concentration was approximately 330 ppm. If the CO2 concentration in 2000 was about 384 ppm, calculate the average rate of increase per year.

Consider the following planned experiment. factor experimental group control group light exposure tots of sun tots of sun amount of water weekly weekly type of soil nutrient rich nutrient rich size of pot large which variable is being tested in this experiment? small a. size of pot b. type of soil c. light exposure d. amount of water