In your letter dated September 12, 2008, to National Academy of Sciences President Ralph Cicerone, you requested that the National Research Council’s (NRC’s) Naval Studies Board (NSB) conduct a study to assess the implications of climate change for the U.S. Naval Services. Accordingly, in August 2009, the NRC, under the auspices of its NSB, established the Committee on National Security Implications of Climate Change for U.S. Naval Forces.

The study’s terms of reference, provided in Enclosure A of this letter report, were formulated by the Chief of Naval Operations (CNO) in consultation with the NSB chair and director. The terms of reference charge the committee to produce two reports over a 15-month period. The present report is the first of these, a letter report issued, as requested, following the third full committee meeting.

The terms of reference direct that this study be based on Intergovernmental Panel on Climate Change (IPCC) scenarios and other peer-reviewed assessments. Therefore, the committee did not address the science of climate change or challenge the scenarios on which the committee’s findings and recommendations are based. In short, this letter report summarizes the immediate challenges for U.S. naval forces in addressing each of the four areas listed below and recommends approaches for addressing these challenges. The terms of reference direct that the committee in its two reports do the following:

1. Examine the potential impact on U.S. future naval operations and capabilities as a result of climate change ….

2. Assess the robustness of the Department of Defense’s infrastructure for supporting U.S. future naval operations and capabilities in the context of potential climate change impacts ….