The IPCC report is very conservative as far as main stream climate science goes. So if you are not convinced by the UN estimates, you must either have a pretty strong counter argument, or you aren't going to be convinced by chunk of glacial ice hitting you in the head.
In terms of looking at the world's energy future, and the decisions that we have to make as a global society, I thought that Nate Lewis' presentation at the symposium presented a pretty good picture of the reality that we are facing. If we wish to create a world that is able to meet the global energy demand without emitting enough carbon gases to raise the atmospheric CO2 concentrations above 350 ppm, and I hope that we are, we have to look at the entirety of the problem. We have to look at the total world demand for energy, and look for solutions, maybe a whole group of solutions, that can address the entire problem. I suggest that anyone that has any interest in the topic of the energy supply to check out Nate Lewis' presentations. The first link is to a video of his presentation last February at the University of Michigan. The second is a presentation that he gave at Cal Tech a couple of years ago. It's basically the same presentation, though the Cal Tech version is longer, and the Cal Tech version offers more information about Lewis's own research into photovoltaic energy production:
U of M symposium
Cal Tech Link
Let me point out that any of the possible solutions to creating a sustainable energy economy include a heavy emphasis on energy conservation. This is a problem that can be solved by technology, but technology alone is not enough without the will.