CO2 Regulatory Certainty Act This bill amends the Internal Revenue Code to revise requirements for the secure geological storage of carbon dioxide for the purpose of the tax credit for carbon dioxide sequestration. The bill establishes a December 31, 2018, deadline and requirements for regulations that the Internal Revenue Service (IRS) is required, under current law, to establish for determining adequate security measures for the geological storage of the carbon dioxide such that carbon dioxide does not escape into the atmosphere. The IRS regulations must consider the carbon dioxide to be disposed of in secure geological storage if it is stored in compliance with specified rules promulgated by the Environmental Protection Agency under the Clean Air Act and the Safe Drinking Water Act for the geologic sequestration of carbon dioxide, the injection of carbon dioxide, and the criteria and standards for underground injection control programs that are applicable to Class II wells. The bill also revises the definition of "qualified enhanced oil or natural gas recovery project" to exclude a requirement for the first injection of liquids, gases, or other matter to commence after December 31, 1990.