system and the national capability to provide nature climate projections represent a climate service to the nation (NRC 1998b, 2001b; USGCRP 2000).
Climate information is increasingly important to the decision-making needs of a wide variety of users. The range of applications is enormous and indicates the impact of climate services. Applications include such diverse entities as water set-asides for instream flows to protect ecosystems, state and national water compacts, building codes, insurance premiums, irrigation and power production decisions, beverage consumption rates, retail clothing volumes, and construction schedules. The applications are also growing with the increased understanding of how climate influences human endeavors. That a weather derivatives industry, designed to manage risk associated with climate variability, is growing rapidly and expanding to include diverse elements of commerce and industry is indicative of the importance of climate services to the nation. The extension of climate capabilities from a relatively straightforward, statistical analysis of historical observations to seasonal and interannual forecasts and to century-scale projections has enabled a broader set of applications, including enhancing productivity in weather-sensitive industries, managing weather risk, protecting life and property, and negotiating international treaties.
Public, private, and academic sectors have all played important roles in the extension. Much of the innovation for individual industry and economic sector use has been developed in the private sector. The academic community continues to improve understanding of climate variability and predictability through its research. The public sector has improved the accessibility of its data and information, including the output from the extensive forecast models now being run. Further, the scientific and user communities are increasingly articulating the improvements required in climate services to enable improvements in decision making.