Low carbon economy is causing the implementation and development of carbon markets that affect an increasing organizations number. These markets entail new challenges to accounting practitioners. The aim of this paper is, on the one hand, to know how the financial statements are being affected by the obligations of companies to control and compensate their carbon emissions, by analyzing the different positions adopted by both regulatory organizations and companies in the practice; and, on the other hand, to analyze the content and specific problematic of accounting statements that report on emissions in physical terms. This paper considers the accounting treatment of new carbon assets and liabilities which external information is not sufficiently regulated. Also, the paper analyzes the new contractual relationships that are being developed such as complex derivative structures, purchasing carbon units through ERPAs (Emissions Reduction Purchase Agreements), carbon monetization, carbon collateralization and carbon funds. Finally, new report requirements to companies that are arising, like Carbon Accounting or risks and strategies regard to climate change (Carbon Reporting), are also analyzed.