Mark Lemon

Mark Lemon

Senior Manager – ESG & Sustainability, Grant Thornton

Mark Lemon is a Senior Manager in Grant Thornton LLP’s ESG & Sustainability practice, leading the firm’s GHG inventory accounting and design services. Mark has over 13 years of experience in management consulting, leading engagements focusing on materiality assessment, ESG criteria inventory and reporting, GHG reporting, performance evaluation, compliance review, GHG assurance readiness and GHG assurance.

Mark also leads Grant Thornton’s internal GHG management program, including annual reporting to CDP, developing Science Based Targets in coordination with SBTi, and reaching GT’s commitment to achieve Net-Zero emissions by 2030.


He is a member of the AICPA Assurance Services Executive Committee Sustainability Task Force, served as the chair of the CAM-I Environmental Sustainability Interest Group and participates in the Indiana University Center for Environmental and Social Responsibility in Supply Chains. He is certified in GRI, GHG Protocol and CDP reporting standards.

Prior to joining Grant Thornton’s ESG & Sustainability practice, Mark was a Senior Manager in the firm’s Financial Transformation advisory practice, managing a host of engagements in data analysis, cost & performance management, and program/project management across private sector, federal government, and higher education industries.

Mark holds an MPA in Environmental Policy and Natural Resource Management from the Indiana University School of Public and Environmental Affairs.