Jonathan is one of the nation’s leading clean economy investors and advisors. Currently a Senior Advisor at Guggenheim Partners, a $300 billion global investment and advisory financial services firm, Jonathan works with cleantech and climate-tech companies globally. He is a member of the boards of National Grid (NYSE: NGG), the British utility and a FTSE 15 company and Plug Power (PLUG: NASDAQ), the country’s leading manufacturer of hydrogen fuel cells. He is also on the board of several privately held, clean economy companies. Until recently, Jonathan was also Managing Partner of Tax Equity Advisors LLC, a major investor in solar power projects.

Named one of the country’s top ten, green-tech “influencers”, he led both the U.S. government’s $40 billion clean energy investment fund and its’ $20 billion advanced automotive technology fund during the Obama Administration. These were, and remain, the largest clean energy funds in the world. He and his team underwrote financing for some of the largest, most innovative and most complex energy projects in the country, including a wide range of solar, wind, geothermal, biofuels, fossil, nuclear and advanced automotive technology projects. His transactions were twice named "Deal of the Year", and one was nominated for "Deal of the Decade" by leading investment publications.

Earlier, Jonathan served as a senior advisor to NextEra, one of the world’s largest utilities and the nation’s largest clean energy investor and operator, ICF, the nation’s largest energy and environment-focused consulting firm and Marathon Capital, the largest power industry-focused investment bank.

Jonathan is on the board of Resources for the Future, the leading economic research firm for energy, environment and natural resource issues and previously served as Chairman of the board of American Forests, the nation’s oldest forest conservation group.

He was the co-founder of venture capital firm Core Capital Partners and Chief Operating Officer of Tiger Management, one of the country's largest and most successful hedge funds. He began his career at McKinsey and Company, the global consulting firm.

Jonathan has served as a senior official in three U.S. Cabinets: Energy, Commerce, Interior and as a senior advisor to the Secretary of the Treasury. He is an expert on how public policy affects investment in energy, sustainability and climate change, has testified frequently on Capitol Hill, been quoted in numerous publications and is a frequent speaker at energy conferences.

Jonathan has served on the boards of the Federation of American Scientists, the Federal City Council, the Community Foundation of the National Capitol Region, WETA (public television), Arena Stage and served as special advisor to the Chancellor of the DC public schools. He is also a Life Member of the Council on Foreign Relations.

For several years, he taught the MBA course on entrepreneurship at Georgetown University.

An honors graduate of Harvard University, Jonathan did graduate work at the Institute of Political Studies in Paris and the Graduate Institute of International Studies in
Geneva while on Fulbright and Rotary Graduate Fellowships. He speaks French and Spanish and lives with his wife and two children in Washington, DC.