Sea ice and glaciers melt almost completely.
1. Unreflected solar rays heat the planet yet more. If its cold here, soon it's not. If it's temperate here, soon it's hot. If it's hot here, soon it's potentially life threatening. Human population has built up where it has because of several factors, the average temperature being one. Migration to the shifting temperate zone could be expected which will lead to later to be discussed factors. Additionally, the hotter air will play a part in changes in weather.
2. Sea levels rise significantly
The height of the rise will determine to what degree, but all coastal areas around the world and many inland areas that actually reside very close to or below sea level, but are separated by higher elevations of land will be lost. A significant amount of human population centers are located in these areas. Whatever could not be moved from these areas will be lost and need to be replaced. The residents of these areas will be displaced, either chronically in a steady organized movement over a few years or acutely in a disorganized evacuation during a serious event ala hurricane Katrina. Those people will have to go somewhere.
3. Sea salinity and temperature will be changed. This influx of large volumes of fresh water will change the very makeup of the water that sea life need to live and the soaking up of solar heat will raise the median temperature. This will reduce the amount of food that can be gleaned from a dying ocean which will definitely impact humans in the form of decreasing food supplies and higher prices for what is still available. Additionally, this change in salinity and temperature will influence ocean currents which plays into the next issue.
4. Weather becomes erratic. Of course you have the leading antagonists of hurricanes, blizzards, and tornadoes, but I think the chronic effects of serious changes to a locale's average weather is more important. Weather is arguably one of the most persuasive factor after economics for the location of human settlement. Certainly, there are people living in places with terrible weather, but there are the exception, not the rule. If precipitation changes to a great degree some areas can become increasingly more difficult to live in. We can, again, expect population movement. We can also expect local food production to change. Crops and wildlife don't like large veers from weather norms and there will be a constriction of food supplies in an affected area. Since we call it "global" warming, that means everywhere.
5. Now we have disease. Changing realities of average temperature, humidity and precipitation can be expected to allow disease that was previously unheard of in an area to take root. Malaria in Kansas? Maybe. Couple this with large groups of people on the move as a result of other factors of this phenomenon and you have the beginnings of waves of pandemic disease. This factor, bred through exodus will accelerate more as people who have thus far been able to avoid serious impact on their lives by other factors are now displaced by the fear of spreading disease. Inland cities, safe from rising water and able to offset food supply problems become increasingly dangerous due to disease spreading amongst people crammed together in a small space.
6. Civil unrest. Now the real panic starts. People have been displaced by all these factors. They are desperate, they are hungry, they are sick, they radiate out into the countryside and the ripples are felt at every corner of the world and somewhere, someone decides it's time to stop being nice and take what they want by force. While we live in a country where guns are readily available, I don't think that really has a bearing on the level of violence. Desperate people do desperate things and we have seen enough examples to suggest if they don't have a gun, they will use a knife, if they have no knife they will pick up a brick. The tools are immaterial here, the systemic breakdown of our modern society is. This is a really complex subject and could easily occupy a voluminous discussion of what this single factor would look like. Let's just paint it with a broad brush and say society is a lot more dangerous than it used to be.
Alright. All that was leading to this. Here you sit, wherever you are, August 2012 and you have decided that this scenario is going to play out. You don't know exactly how it will unfold or how quickly, but you are confident all these things are coming at whatever speed and style they choose and you want to position yourself for this future.
What do you do?
What is the likelihood friends and family will share your feelings and be willing participants in the evolution of your lifestyle?
What changes will you make immediately to establish the foundation for your long term plans?
What skills, tools or other things do you need to acquire to better prepare you?
If you have decided you must leave your current location, what is the influencing factor and where would you go?
Regardless of if you stay where you are or leave, how will you prepare your living spaces?
How would you evolve as conditions deteriorate? Do you take measured steps or take a dramatic move at a certain point? If the latter, what would trigger it and why?
Do you have more faith in pulling together as a community than going it alone? if so, why and what size of group do you think is best?
If you have more confidence as an individual, why?
Discuss
But I sure looked good while limping into the Doctors office 
. but I Learned my lesson and keep it at 6 careful workouts a week now.
