Interpreting Data: Atmospheric Concentrations of Greenhouse Gases 2 of 3 > I Review Use the graph to answer these questions about concentrations of three greenhouse gases Part A 400 2,000 Which gas is plotted using the y-axis on the right? 1.800 Carbon Dioxide (CO) Nitrous Oxide (NO) Methane (CH) 1,600 Carbon dioxide (CO2) 350 1,400 Methane (CH) CO, (ppm), No (parts per billion) Nitrous oxide (N2O) 300 1,200 1,000 3 The total of all three gases 800 Submit Request Answer 250 600 0 500 1000 1500 2000 Year Data from mate Change 2007: The physical science bases: Contribution of Working Group Part B la the urth portation Plan Change Which of these three gases is most abundant in the atmosphere? O Carbon dioxide (CO2) Nitrous oxide (N2O) Methane (CH4) ) The concentrations of the three gases are approximately equal.