Last week the Defense Science Board released its study, "Trends and Implications of Climate Change for National and International Security" (175 pgs):
http://www.acq.osd.mil/dsb/reports/2...ate_Change.pdf

I have not finished reading the entire report, but it is clear from the outset that the DSB views CC as ongoing and serious, and that it accepts the "compelling evidence that climate impacts are observable, measurable, real, and having both near and long-term consequences" (p. vii).
The report has a particular focus on Africa, water and the potential for failed states.
The report also contains a detailed set of recommendations for various federal agencies (both civilian and military).