Climate change is an issue that is of concern to many emergency mangers.
It is, based on my limited understanding of the science, not "global warming" that we need to worry about per se. We need to be concerned about the risk of a major change in global weather patterns.
In my experience, many EM offices are adding this to the list of things to worry about (or HVA in most cases). I have seen it mentioned in several RFPs for instance.
If the predictions are correct and the trend continues, climate change will lead to an increase in weather related disasters. Weather patterns may shift to impact areas not typically prone to a particular weather hazard. As we already know, despite what mitigation is occurring (or not), weather-related disasters will continue to increase because of population growth in vulnerable areas - now our paradigm as to what is a vulnerable area, and what are the prevalent hazards, may need to shift (example, Atlanta went from drought to floods in this decade).
Climate change, as I understand it, can potentially have a pronounced effect on the evaporation rates and on the distribution of water vapor and clouds in the atmosphere and of ice at the polar caps. Whether it is greenhouse gases or a cycle of climate change, climate change will certainly increase the frequency and intensity of weather related disasters.
Emergency Managers should be reevaluating risk and vulnerability due to weather patterns changing, potentially in dramatic fashion. This will increase the need for better mitigation, preparedness, awareness, and education for many.
So, it will be necessary to evaluate the vulnerabilities of climate change and the short and long-term risks of potential disasters. The usually look at historical occurrences may become less meaningful. A sound assessment of risk will require some new thinking and better hazard modeling. Then we will need to do what we do: Mitigation, preparedness, response, and recovery.