Great video. It's encouraging to see that prices are falling so dramatically. However, that doesn't mean that we're off the hook. Time is the critical factor--once we pass certain tipping points, climate system feedback loops may kick in and lead to unstoppable changes. For example, melting glaciers mean that less sunlight is reflected back into space and thus more heat is absorbed, which leads to more melting. Note that once in progress, this effect does not depend on the future level of greenhouse gases.
The cost advantage of renewable energy sources will likely mean that China, India and less developed countries will turn to them for their future development, which is very good news indeed. But what about the huge world-wide existing infrastructure of fossil fuel based energy? Can we replace it in time? Where will the needed capital come from, especially in poorer countries? Cars and electricity production are responsible for only about half the greenhouse gas emissions in the world. What about home heating and livestock production?
@jpop: I completely agree that we must avoid sinking into despair. You are right that some solutions exist, but I believe we shouldn't let that lull us into complacency. The problem is too big and the time is too short to think that the market will just take care of everything. Some governments are taking action as are some states within the US. But I find it discouraging that climate change is only rarely mentioned in electoral politics when it is really the elephant in the room. We can and must do better.