Research on this topic is making waves. A 2011 report, in which Shepherd participated, found that new national security challenges will arise for the U.S. Navy, Marine Corps and Coast Guard if even moderate trends in climate change continue.
"Military, security, and intelligence analysts are now engaged with the issue, and there's a great deal of thought now being given to the long-term security implications of climate change," Homer-Dixon wrote in an email. "There's very little skepticism within these circles about the reality of climate change, nor about the potential risk climate change poses to national and international security."
The scientific community agrees that human activity -- namely burning coal, oil and natural gas -- has been driving a rapid rise of carbon dioxide levels in the atmosphere. This is analogous to turning the dial up on an electric blanket, says Jim Butler, a senior scientist at NOAA; it takes a little while to warm up, and even if we stop emitting carbon dioxide, temperatures would still rise for a decade or two.
Indirectly, analyses such as Hsiang's can influence discussions about climate policy in general.
"If the world that these studies project will arrive in mid-century looks pretty unpleasant, then one obvious response is to be more serious about reducing greenhouse gas emissions," Homer-Dixon said.
It remains to be seen whether this research will indeed get policy makers hot and bothered enough to enact change.