A changing climate means more work for humanitarian organizations. Vulnerable people served by the Red Cross/Red Crescent Movement are likely to experience new patterns of disasters. In the face of these rising dangers, science-based information about likely threats can be used to reduce risk and improve resource allocation. Examples such as the 2008 emergency appeal for flood preparedness in West Africa illustrate the benefits of turning early warnings into early actions at community, national, and regional levels, at timescales ranging from hours to decades ahead of a looming threat. By making better use of a wide range of new information, humanitarian organizations can enhance their work even in the face of the rising risks of climate change.