This research service focuses on the United States (US) Department of Defense (DoD) environmental activities. The base year is FY 2021, and it provides examples of fiscal year (FY) 2023 program spending requests, and representative contracts awarded during calendar year (CY) 2022. The study outlines DoD's efforts to address pollution at bases, improve energy efficiency, implement alternative power sources, and plan for a more environmentally sustainable future. The research includes budgets requests and contracts for research, procurement, and services while indicating major funding priorities. In addition, the study highlights examples of contracts and key market participants while also outlining DoD environmental activity spending drivers, restraints, and technology interests, as demand for innovative green and clean products and services increases. Additionally, the study emphasizes the interdisciplinary nature of energy and environment sustainability requirements for cross-industry input. The DoD Environmental Activities market is mature and stable, and this study outlines and provides commentary on budget trends. The goal is to understand the current state of DoD's budget request, operational trends driving the DoD Environmental Activities, and the future objectives for DoD spending. Author: Brad Curran