Carbon Pollution Transparency Act This bill requires the heads of federal agencies, when making certain rulemaking or procurement decisions, to consider and document the cost of carbon dioxide, methane, and nitrous oxide emissions in accordance with a set of standardized amounts. The bill establishes the Interagency Working Group on the Costs of Greenhouse Gases to evaluate, at least once every five years, the method of calculating the cost of carbon dioxide, methane, and nitrous oxide. The bill also establishes the Costs of Greenhouse Gases Scientific Review Committee to make recommendations to the working group regarding revisions to the calculation method. The 10 members of the committee must be selected by the National Academies of Sciences, Engineering, and Medicine and represent relevant scientific fields.