National Intelligence Assessment on the National Security Implications of Global Climate Change to 2030
"... We judge global climate change will have wide-ranging implications for US national security interests over the next 20 years. Although the United States will be less affected and is better equipped than most nations to deal with climate
change, and may even see a benefit owing to increases in agriculture
productivity, infrastructure repair and replacement will be costly. We judge
that the most significant impact for the United States will be indirect and
result from climate-driven effects on many other countries and their
potential to seriously affect US national security interests..."