”There is compelling reason to presume that specific failures of adaptation [to climate change] will occur with consequences more severe than any yet experienced, severe enough to compel more extensive international engagement than has yet been anticipated or organized.”
The National Research Council is the principle operating arm of the National Academy of Sciences, the National Academy of Engineering and the Institute of Medicine. The entire summary of the study:
Core features of the climate change situation are known with confidence. The greenhouse effect associated with the carbon dioxide molecule has been measured, as has the dwell time of that molecule and its concentration in the atmosphere. We also know that the rate at which carbon dioxide is currently being added to the atmosphere substantially exceeds the natural rate that prevailed before the rise of human societies. That means that a large and unprecedentedly rapid thermal impulse is being imparted to the earth’s ecology that will have to be balanced in some fashion. We know beyond reasonable doubt that the consequences will be extensive. We do not, however, know the timing, magnitude, or character of those consequences with sufficient precision to make predictions that meet scientific standards of confidence.
In principle the thermal impulse could be mitigated to a degree that would presumably preserve the current operating conditions of human societies, but the global effort required to do that is not being undertaken and cannot be presumed. As a practical matter, that means that significant burdens of adaptation will be imposed on all societies and that unusually severe climate perturbations will encountered in some parts of the world over the next decade with an increasing frequency and severity thereafter. There is compelling reason to presume that specific failures of adaptation will occur with consequences more severe than any yet experienced, severe enough to compel more extensive international engagement than has yet been anticipated or organized.
This report has been prepared at the request of the U.S. intelligence community with these circumstances in mind. It summarizes what is currently known about the security effects of climate perturbations, admitting the inherent complexities and the very considerable uncertainties involved. But under the presumption that these effects will be of increasing significance, it outlines the monitoring activities that the intelligence community should be developing in support of improved anticipation, more effective prevention efforts, and more decisive emergency reaction when that becomes necessary.
Figure 1-1 illustrates the evolution of the distribution of the Northern Hemisphere land Temperature Anomaly for Jun-Aug.
The report makes some recommendations regarding monitoring:
As we have also noted, the connections between climate events and national security concerns are complex and contingent, with many plausible combinations of climatic events with social, economic, and political conditions that might create risks to U.S. national security. These risks are unlikely to be foreseen by looking only at climate trends and projections or by looking only at political and social trends and projections. To anticipate the risks, analysis needs to integrate three kinds and sources of knowledge: (1) knowledge of political and socioeconomic conditions in countries of interest, (2) knowledge from climate science about the potential exposure of these countries to climate events, and (3) knowledge from social science about the susceptibility of these countries to be harmed by those events and the likelihood of effective coping, response, and recovery at local to national levels. These sources of knowledge come from different communities of experts, which will need to communicate with each other. Making this happen will take time and continued effort.
And yet, we are currently on the wrong path, as the report’s lead author noted in a NYT article:
Yet Mr. Steinbruner said that as the need for more and better analysis is growing, government resources devoted to them are shrinking. Republicans in Congress objected to the C.I.A.’s creation of a climate change center and tried to deny money for it. The American weather satellite program is losing capability because of years of underfinancing and mismanagement, imperiling the ability to predict and monitor major storms.
For instance the last Republican House budget would have reduced funding for NOAA, which in turn operates the satellites that monitor weather. 
Source: N. Collins, “Hurricane Sandy: what is causing the ‘Frankenstorm’?” Telegraph, Nov 11, 2012.
For the few people who still think there is a lack of consensus on anthropogenic sources of global climate change (and probably still think the polls were biased against Mitt Romney, and that a shadowy conspiracy in the BLS rigged the September employment statistics), see here.