Observations and monitoring systems have been major elements of the U.S. Global Change Research Program (USGCRP) sponsored scientific studies throughout the past thirteen years. Because additional space-based and in situ data are needed to significantly improve scientific analyses and 6  computer models, and because stable, long-term measurement records are essential to interpret Earth system variability and trend data, there is a critical need for a well-designed, comprehensive climate and ecosystem monitoring system. A comprehensive monitoring system necessarily will be global in scope, and the United States should continue to make leadership contributions to the global system design and implementation.

The United States is already contributing to the development and operation of several global observing systems, including support for a wide array of NASA and National Oceanic and Atmospheric Administration (NOAA) satellites, the Argo floats being deployed in the world's oceans, the Global Climate Observing System (GCOS) sponsored by the World Meteorological Organization, and the Global Ocean Observing System (GOOS) sponsored by the Intergovernmental Oceanographic Commission. In the past, resources required to operate these operational observing systems, as well as the operational data management and distribution systems, have not been a part of the USGCRP. The new integrated climate program organization is expected to include these programs and to consider the necessary improvements.

• Generation of "climate-quality" data, with stable measurement methods, consistent exposures, good intercomparison between data sets, and back- and forward- standardization of long-term data records.  
• Development of new observing capabilities to illuminate Earth system processes and increase spatial, temporal, or spectral resolution where needed to reduce key uncertainties in climate change and address emerging Earth science questions.  
• Provisions for high-quality data assimilation methods, combined with efficient archiving and retrieval methods, to facilitate research, analysis, and forecasting applications.  
• Creative capture of the relevant information from the myriad of special research projects conducted throughout the world during recent decades, to optimize the information available for scientific analysis and improve computer model evaluations of global change and climate change.  
•  Special emphasis on the complex observations and monitoring systems needed to analyze terrestrial and aquatic ecosystem variability.