of Independent Registered Public Accounting Firm
consent to the incorporation by reference in the Registration Statement of Carbon Natural Gas Company on Form S-8 (files No. 333-179184)
of our report dated March 31, 2016 relating to the audit of the consolidated financial statements for the years ending December
31, 2015 and 2014, appearing in the Annual Report on Form 10-K of Carbon Natural Gas Company for the year ended December 31, 2015.