Industry supports the government in developing, deploying, and operating Earth observation systems used to ensure national security. These systems provide essential science data used in real-time detection of weather, forecasting of long-term climate change, and monitoring of hazards. Science communities for weather, climate and hazards have established target sets of essential observables. The results of an assessment of the capacity of current and planned systems to provide these essential variables is described. An approach for a future Earth observation system architecture that integrates data collected from geostationary and polar-orbiting satellites with Unmanned Aerial System (UAS) platforms is formulated. This approach includes configuring operational environmental monitoring satellites, NPOESS and GOES R, augmented by UAS vehicles such as the Global Hawk with complementary modeling and decision support system. The candidate architecture has the capacity to deliver innovative environmental data collection capabilities over a range of environmental conditions, including such severe hazards as hurricanes and extreme wildland fires. A set of metrics that includes sustainability, interoperability, and capacity to contribute to science data products are introduced to evaluate the approach. The performance of the current and planned systems configurations are evaluated against several factors that include long term capacity for measuring essential climate variables (ECVs), environmental data records (EDRs), and solid Earth hazard parameters. Seven dimensions of an Enterprise approach for a sustainable, global capacity are presented. Emphasis is given to achieving enhancements to capacity to measure global changes associated with climate, deliver well-calibrated and validated data for weather forecasting, and capacity to effectively deliver timely information associated with a range of hazards. An approach to formulating an enterprise architecture that brings together space and airborne systems with ground and ocean observing sensors as a vertically integrated global observing system for climate-related measurements and determination of uncertainties is described.