Before implementing a global carbon tax maybe the IPCC predictions should be looked at more closely, no?
The IPCC first assessment report(still available on their site) had temperature projections that we can compare today to see how they match reality nearly 25 years later. Take a look for yourself, and they clearly predict a warming of 0.5C from 1990 temperatures by 2014 IF CO2 emissions remained frozen at 1990 levels. So, sort of their best case scenario. In reality, CO2 emissions have steadily climbed much, much higher than 1990 levels. Today's temperatures though sit at a warming of 0.4C higher than 1990 levels.
The IPCC more recent third assessment from 2001 has much improved projections, and we can again compare them to reality 15 years out. The 2001 assessment has error bars included and a decade more research and refining behind it. If you compare it as well, you see today's temperatures DO fit within the error bars projected 15 years ago by the IPCC, albeit barely. Of course, they are way, way down on the lowest end of the error bars.
What the above tells me is that reality has shown the IPCC has consistently been overestimating the amount of warming to be expected. In other words, the science says don't panic just yet.
Switching to electric cars and nuclear power are a good idea regardless of CO2 emissions, so we should push forwards with them. If for no other reason than they are simply better and cheaper if we invest in them properly. A massive reduction in CO2 emissions that comes with it is entirely secondary as a side benefit. Really, less coal smoke and exhaust fumes are probably the bigger win. Particularly in places like China were even seeing the sun is become rare indeed.