As CEO of EcoAct North America, William Theisen oversees the growth of the EcoAct North America team while ensuring we continue to raise the bar in terms of quality and drive innovation in our Business Advisory and Nature & Technology Based Solutions so that our North American clients can achieve their net-zero ambition in line with best practice. William has over 15 years of experience working with private and public sectors to develop and implement comprehensive net-zero strategies. William joined EcoAct in 2015 in the Paris office and then launched EcoAct’s North America operations in 2017. A graduate from Boston University with an MBA from HEC Paris, William began working in sustainability at the Gold Standard Foundation, a certification body headquartered in Geneva that evaluates carbon reduction and sustainable impacts using results-based methodologies. Following this role, he worked with NGOs Nexus for Development and the Group for the Environment, Renewable Energy and Solidarity (GERES) to scale-up more than a dozen carbon reduction projects in Asia and Africa by leveraging innovative market mechanisms.