Climate change will pose a serious and intractable threat to the health of populations. The ability of the public health system to address this problem and to preserve and protect the health of the public depends on a robust surveillance system. While public health has a long history of surveillance, the current system is not prepared to respond to the health effects of climate change. In order to develop a robust surveillance system, the public health infrastructure must address several issues, including coordination problems, conflicting legal authorities, jurisdictional issues, an overemphasis on preparedness, and complex issues of management and long-term planning.