Sam Whittemore

Sam is a partner in Bridgespan’s New York office and leads Bridgespan’s Climate and Environment practice. Since joining Bridgespan in 2015, he has advised philanthropists, impact investors and nonprofit organizations on strategy, organizational development, and the design of large-scale philanthropic initiatives. Sam has worked extensively with climate and environmental organizations including the Pew Charitable Trusts, Global Methane Hub, Outlier Projects, Clean Air Fund, and Conservation International.

A significant portion of Sam’s work focuses on helping funders build ambitious, new initiatives that can deploy capital at scale. He has supported the creation and launch of several major philanthropic initiatives, including multi-donor efforts focused on accelerating carbon dioxide removal solutions, advancing safer chemicals policy and practice, strengthening election administration infrastructure, and combating contemporary antisemitism in the United States. His work often involves helping funders develop investment strategies, governance structures, measurement approaches, and operating models for complex initiatives and pooled funds.

Alongside his climate and environmental work, Sam increasingly advises philanthropists and nonprofit leaders on questions related to democratic resilience, pluralism, and the future of civil society. He recently co-authored an article exploring how civil society organizations can adapt to a period of declining institutional trust, political polarization, and rapid technological change, “The Changing Role of Civil Society in the United States: Reflections for Nonprofit and Philanthropic Leaders” (Bridgespan.org, 2026).

Sam also advises impact investing organizations on impact measurement and diligence methodologies, particularly in climate-related sectors. With Texas Pacific Group’s (TPG) Rise Fund, Sam and a Bridgespan team helped develop and implement a rigorous quantitative approach to impact underwriting, as detailed in Harvard Business Review’s “Calculating the Value of Impact Investing” (2019) and HBR’s case study “The Rise Fund: TPG Bets Big on Impact” (2018).*

Prior to joining Bridgespan, Sam was a member of the founding team of Precision Agriculture for Development, a startup focused on transforming the way farmers receive agricultural extension services. While in graduate school, he worked with the United States Agency for International Development for the Development Innovation Ventures group evaluating early-stage enterprises in sub-Saharan Africa and Southeast Asia. Sam also worked for the Analysis Group as an economic consultant supporting companies involved with complex corporate litigation, and with BRAC in West Africa evaluating effectiveness of new microfinance lending programs.

Sam holds an MBA from the Kellogg School of Management, where he was an FC Austin Scholar, and an MPA from the Harvard Kennedy School. He graduated magna cum laude from Carleton College.

* Services to the impact investing industry are provided by Bridgespan Social Impact, Inc., a wholly owned subsidiary of The Bridgespan Group.