He was one of the 35 Nobel laureates who signed a letter urging President Obama to provide a stable $15 billion per year support for clean energy research, technology and demonstration.
他还曾与另外34位诺贝尔奖得主签署一封信，敦促奥巴马总统提供一个150亿美元的稳定预算，支持清洁能源的研究、技术和示范。