Board of Directors

Maria Lettini, CEO

Maria Lettini is the Chief Executive Officer of US SIF: The Foum for Sustainable Investment. She joined US SIF in May of 2023 and is an innovative leader within the fields of sustainability and finance.  She is recognized for building meaningful partnerships across the capital markets value chain to address some of the world’s most critical, and financially material, environmental and social challenges.

For more information on Maria Lettini, click

Diederik Timmer, Chair

Diederik Timmer is the Managing Director of Corporate and Climate Solutions at Sustainalytics. Over the past decade, Diederik has helped build Sustainalytics into the largest independent provider of ESG research and analysis for the global investment community. He acts as an advisor to senior executives, portfolio managers, and risk professionals on developing and implementing ESG, SRI and Impact strategies. Diederik directly manages the Institutional Relations team, whose members earned the top three positions in the Independent Research in Responsible Investment (IRRI) Survey for Best SRI Client Services representatives in 2012. 

Prior to joining Sustainalytics, he managed research projects at Nyenrode University in The Netherlands, where he contributed to multiple academic publications. He's married to his long-term partner Sarah, has a 7-year-old son named Hugo and lives in Brooklyn, NY.

Iyassu Essayas, Vice-Chair

Iyassu Essayas is the founder of E&I Consulting Services and has spent over a decade in the responsible investing field. E&I Consulting Services partners with clients seeking to develop strategies incorporating sustainable, responsible and impact investing into their internal programs and policies.
Iyassu was previously the Director of ESG Research at Parnassus Investments. He was responsible for oversight of the development and implementation of Parnassus’s responsible investment policy as well as the integration of environmental, social, and governance research into the firm's investment process. He received his bachelor's degree in biology from the University of San Francisco.

Kimberly Gluck, Treasurer

Kim is a Managing Director and a member of the Boston Trust Walden Board of Directors and manages portfolios for institutional and individual clients. She is a member of the Securities Research, Corporate Governance, and ESG Research & Engagement Committees.

Prior to joining the firm in 2011, Kim was a Managing Director at Atlantic Trust and a Senior Relationship Manager and Portfolio Manager for six years, primarily serving high net worth clients. Previously, she worked with State Street Global Advisors as a Portfolio Manager and Product Engineer for over ten years and helped to establish their socially responsible investment (SRI) program.

Kim earned a BA in Economics from Middlebury College. She holds the Chartered Financial Analyst® designation and is a member of the CFA Society Boston and the CFA Institute. She currently serves on boards and committees for the United Methodist Foundation of New England, the Second Church of Newton, and The Boston Club. She is also a member of the Women Donors Network.

Stephanie Cohn Rupp, Secretary

Stephanie Cohn Rupp is a Partner and Chief Executive Officer of Veris Wealth Partners, a leading impact and ESG-only wealth management firm in the United States. She is an executive leader with more than 20 years of global impact investing experience. During her career, Stephanie has focused on building scalable, profitable, sustainable businesses. Based in San Francisco, she helps lead the firm’s impact wealth management growth strategies, financial performance and client experience.

Before joining Veris, Stephanie was Managing Director and Partner, Head of Impact Investing, at Tiedemann Advisors and Threshold Group, where she served clients as a wealth advisor and led the development of the impact investing platform and impact client experience. Prior to that, she was CEO of Toniic, a global community of impact investors which she grew tenfold. Previously, Stephanie held globally focused investment roles at Omidyar Network, PlaNet Finance, UBS, The World Bank and building greenfield micro-finance institutions financed by USAID.

Stephanie is a member of the ImpactAssets 50 Review Committee, Confluence membership committee and an advisory board member to Paris-based Investisseurs et Partenaires’ investment fund for education in Francophone Africa.
She earned a Master of Public Administration from the Harvard University Kennedy School of Government and a Master of Science from the London School of Economics and Political Science. She is a French and U.S. binational and co-authored The ImpactAssets Handbook with Jed Emerson.

Anthony Eames, At-Large Member

Anthony serves as Vice President and Director of Responsible Investment Strategy for Calvert Research and Management, an affiliate of Eaton Vance. For 25 years, his career has centered on providing education, insights and portfolio positioning to investment professionals and clients about the benefits of sustainable and responsible investing. 
Anthony led the business development and client service efforts of Calvert ahead of the 2016 acquisition of Calvert Investment Management’s assets by Eaton Vance. He developed the transition strategy to EV, carrying forward the history of Calvert’s responsible investment research and engagement process, building and integrating a new strategic vision, and developing and growing the specialist and product management team. He is responsible for client communications and insights on investment strategy and portfolio positioning. He is also a director of the Calvert Institute for Responsible Investing, Calvert Research and Management’s research and innovation arm, and is often called upon as a subject matter expert for stage and media appearances.
A graduate of Wittenberg University, Anthony is also an Accredited Investment Fiduciary (AIF), Accredited Asset Management Specialist (AAMS), and Global Financial Steward (GFS), and holds FINRA Series 7, 24, and 63 licenses.

Kimberly Griego-Kiel, At-Large Member

Kim is the CEO of Horizons Sustainable Financial Services, Inc., a majority woman owned RIA firm in Santa Fe, NM. She has been working directly with clients for over 20 years in the Impact Investing space, which includes; individuals, small businesses, and local non-profits.

In her capacity as the majority owner and CEO, she not only work with clients directly, but is the Chief Compliance Officer, overseeing a small but mighty team of Advisors from around the country. She has a twice-monthly Podcast, Deep Impact Investing, as well as the occasional contribution into the asset management of client accounts. She speaks on a variety of topics at both in-person and now virtual events across the country. She has a great team and they have managed to grow the firm’s assets by nearly 500% since 2008. She is strongly committed to the goals of impact investing in all client portfolios.

Linda-Eling Lee, At-Large Member

Linda-Eling Lee is the Global Head of ESG and Climate Research at MSCI. MSCI ESG Research is the largest provider of ESG and Climate analytics to global institutional investors. Linda oversees all ESG- and Climate-related content and methodology, leading one of the largest global teams of analysts in this field. The team has been widely recognized as the best SRI/ESG researchers by market surveys and awards.
Linda joined MSCI in 2010 following the acquisition of RiskMetrics, where she led ESG ratings research and was head of consumer sector analysis. Linda joined RiskMetrics Group in 2009 through the acquisition of Innovest. Previously, Linda was the Research Director at the Center for Research on Corporate Performance, developing academic research at Harvard Business School into management tools to drive long-term corporate performance. She started her professional career as a strategy consultant with Monitor Group in London, then Hong Kong, Athens and Frankfurt, serving Fortune 500 clients in industries ranging from beverages to telecommunications.
Linda’s research has been published in both investment practitioner as well as top academic peer-reviewed journals. She is a frequent media commentator in outlets including the Financial Times, Wall Street Journal, Bloomberg, Forbes and The New York Times. Linda has been honored to receive a number of industry accolades over the years, including a Top 100 Women in Finance by Barron’s in 2019 and 2021, and voted #1 for an Individual Making the Most Positive Overall Contribution to Sustainable Investment / Corporate Governance in 2018 and 2019 by Extel/IRRI.
Linda was born in Taiwan and moved to Seattle at a young age. She is based in New York City where she has been raising three children over the past two decades. Linda received an AB from Harvard, MSt from Oxford, and PhD in Organizational Behavior from Harvard University.

Jonas Kron, At-Large Member

Jonas Kron is Trillium Asset Management’s Chief Advocacy Officer. With almost 20 years of experience in shareholder advocacy, Jonas is responsible for leading and coordinating Trillium’s extensive advocacy program, which works to engage companies on their environmental and social performance. His advocacy work includes direct communications with company leadership, investor education and awareness, filing shareholder proposals, and public policy advocacy at the municipal, state and federal levels. As a recognized legal expert in the field and a leader in shareholder advocacy, Jonas regularly represents Trillium in the media, at public events, and with clients.

Prior to joining Trillium, Jonas was an environmental attorney and public defender as well as outside counsel to many socially responsible investment organizations. Jonas holds J.D. and masters degrees from Vermont Law School.

Mamadou-Abou Sarr, At-Large Member

Mamadou is the founder and President of V-Square Quantitative Management, a subsidiary of Valor Equity Partners. Mamadou founded V-Square Quantitative Management in 2020 after an accomplished career in asset management whilst working for global financial services company across the U.S., Europe, Middle East, and Africa. His investment firm specializes in financial engineering, development and management of quantitative portfolios and processing of sustainability big data.
An industry leader in the field of sustainable investing and financial innovation, Mamadou’s previous role was global head of product development and sustainable investing at Northern Trust Asset Management in Chicago, where he was responsible for driving innovation and product development across asset classes. Mamadou spearheaded, developed, and led one of the largest sustainable investing platforms in the industry.
He has published many articles and papers in professional and academic journals including Pensions & Investments, European Pensions, Environmental Finance, and the Journal of Portfolio Management. Mamadou has also spoken at more than 150 conferences in North America, Europe, Asia, Middle East and Australia and is an Adjunct Faculty member for ESG Investing at the Baumhart Center MBA, and a guest lecturer on sustainability at University of Chicago, Wharton and ESCP Business School.
Mamadou is actively involved in philanthropic and civic activities. He is a board member of the Nature Conservancy Illinois Chapter, a member Rush Health Equity Advisory Council (Rush Hospital) and a member of the committee on Photography at the Art Institute of Chicago. He also serves at the ESCP business school Research Center for Energy Management (Member of the Advisory Board); French American Cultural Exchange (FACE -Founding member of FACE in Chicago) and a member of various committees of the Principles for Responsible Investment (PRI).
In 2014 he was named in the Financial News “Top 40 under 40 Rising Stars in Asset Management” in Europe, Middle East, and Africa. In 2017, Mamadou was named a “40 under 40” by Crain’s Chicago Business. In 2017 he was also recognized in Top 50 Individuals who contribute the most sustainable & responsible investment industry in the world (IRRI). He is a fellow of Leadership Greater Chicago since 2019, a member of the Economic Club of Chicago and an Executive Fellow of the Baumhart Center.
Mamadou is a French Foreign Trade Advisor, appointed by decree of the Prime Minister of France.

Julie Gorte, At-Large Member

Julie Gorte is Senior Vice President for Sustainable Investing at Impax Asset Management. Julie works with the Sustainability team and is responsible for maintaining Impax’s thought leadership. Julie maintains an extensive database of financial and academic papers that link sustainability, and all its aspects, to financial and economic outcomes, and provides regular updates on changes in and emerging themes in sustainable investing, focusing on value drivers in the transition to a sustainable economy. Julie also engages with companies to urge them to be more sustainable, and to learn about the headwinds and tailwinds involved in the sustainability transition. Lately, Julie has led major engagements with multiple companies on the physical risks associated with climate change, and building resilience as we experience more storms, floods, droughts, wildfires and sea level rise. Prior to joining Impax, Julie was a Vice President at Calvert, doing many of the same things she does at Impax, and overseeing the sustainability research team. In my pre-financial industry life, Julie has worked as a senior analyst for both executive and legislative agencies in the Federal government, specializing in climate and environment, the trajectories of technology, and labor rights and transitions.

Dan Hanson, At-Large Member

Dan Hanson is the Managing Director and joined Neuberger Berman in January 2022, as the Senior Portfolio Manager and Head of the U.S. Sustainable Equity team. Dan brings a 25+ year history of managing US and global equity institutional portfolios and have maintained a top quartile ESG track record dating back to 2006. Dan has been an advocate for sustainable investing for over 15 years.

Dan joined Neuberger Berman from Waddell & Reed and Ivy Investments, where he was Chief Investment Officer, responsible for leading an $80B AUM franchise. Previously, Dan served as Head of Impact Investing for JANA Partners. Prior to that role, Dan was Partner and Head of U.S. Equities, and Co-Chair of the Investment Strategy Committee with Jarislowsky Fraser Global Investment Management ($30B AUM). Previously, Dan spent 10 years at BlackRock where in 2006 he launched and managed the firm’s first fundamental, active ESG strategy, and served as a voting member of the firm’s proxy committee. Dan is an active shareholder advocate, and have been involved in a number of initiatives in the area of governance, corporate reporting, and sustainable investing.

Dan was a founding member of the board of directors of the Sustainable Accounting Standards Board (“SASB") from 2011-2016, and created the SICS® classification system in 2012 (SASB Materiality Map®). Advisory and board roles have included UC Berkeley Law, Journal of Impact & ESG Investing, Canadian Coalition for Good Governance (CCGG), International Integrated Reporting Council (IIRC), Global Initiative for Sustainability Ratings (World Business Council for Sustainable Development), and the IFRS International Sustainability Standards Board (ISSB) Investor Advisory Group (IAG). Dan served on the professional faculty of the University of California-Berkeley Haas School of Business, where he taught sustainable investing from 2016-2019. In that role, Dan was a judge for the Moskowitz Research Prize, which recognizes outstanding quantitative research in sustainable and responsible investing. Dan has been a member of the Northwestern Kellogg Impact & Sustainable Finance Faculty Consortium since its founding in 2018. Dan is an author and contributor to various articles including "ESG Investing in Graham & Doddsville" in the Journal of Applied Corporate Finance, "The 21st Century Investor: Ceres Blueprint for Sustainable Investing", and the "Impact Investing" chapter in Responsible Investing (Routledge, 2018). My article "The ‘Science’ and ‘Art’ of High Quality Investing" was winner of the IRRC Institute 2016 Practitioner Research Award presented at Columbia University's Millstein Governance Forum. Dan received his Bachelor’s Degree in Economics and French from Middlebury College, and earned an MBA, Accounting and Analytic Finance, from The University of Chicago. Dan is a CFA charter holder.