FIGURE 63.8 Historic concentrations of CO2, methane, and nitrous oxide. Using samples from ice cores and modern measurements of the atmosphere, scientists have demonstrated that the concentrations of all three greenhouse gases have increased dramatically during the past 200 years.
(Data from IPCC, 2007: Summary for Policymakers. In Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, ed. S.D. Solomon, et al. Cambridge University Press.)