Growing Climate Solutions Act of 2021 This bill authorizes the Department of Agriculture (USDA) to establish a voluntary Greenhouse Gas Technical Assistance Provider and Third-Party Verifier Certification Program to help reduce entry barriers into voluntary environmental credit markets for farmers, ranchers, and private forest landowners. A voluntary environmental credit market is a market through which agriculture and forestry credits may be bought or sold. Entities eligible to participate in the program are (1) providers of technical assistance to farmers, ranchers, or private forest landowners in carrying out sustainable land use management practices that prevent, reduce, or mitigate greenhouse gas emissions, or sequester carbon; or (2) third-party verifiers that conduct the verification of the processes described in the protocols for voluntary environmental credit markets. Among other requirements, USDA must publish (1) a list of protocols and qualifications for eligible entities; (2) information describing how entities may self-certify under the program; (3) information describing how entities may obtain the expertise to meet the protocols and qualifications; and (4) instructions and suggestions to assist farmers, ranchers, and private forest landowners in facilitating the development of agriculture or forestry credits and accessing voluntary environmental credit markets. USDA must also establish an advisory council to make recommendations regarding the list of protocols and qualifications, best practices, and voluntary environmental credit markets. The bill also rescinds certain funds provided in the American Rescue Plan Act of 2021 and makes the funds available for the certification program.