In recent statements , three top environmental experts -- Fred Krupp , the executive director of Environmental Defense , and Jonathan Lash , the president of the World Resources Institute and James Gustave Speth , the dean of Yale 's School of Forestry and Environmental Studies -- have stopped well short of embracing nuclear power , but they have emphasized that it is worth trying to find solutions to the economic , safety and security , waste storage and proliferation issues rather than rejecting the whole technology .