You're right, fossil fuels are too cheap and viable alternatives will not be implemented until they are cost effective compared to fossil fuels. One of the reasons why fossil fuels are comparatively inexpensive is that, unlike nuclear energy for example, the "clean up" costs are not factored in.
This is correct and universally applicable. Cradle-to-grave analyses of energy technologies is often avoided by proponents because it brings unwelcome information to the fore. Fermentation ethanol, bio-diesel, hybrid vehicles, the so-called hydrogen economy, nuclear power, undersea CO2 sequestration as hydrates, and other such "solutions" have problems and unintended consequences of their own. Each tribe will select what they perceive to be the least of the evils and push to convince the other tribes that they have the solution. Failures are inevitable and some tribes rejoice when another tribe's pet solution fails or has a setback.
As to fossil fuels, at present, the world is too dependent on them and has an infrastructure designed for their use in place, so the ability to change is limited and the cost of change is too high to absorb in a short time frame. This conversion will require sequential steps to make the transition, smoothly and with minimal disruption. The pathway here is to use less, of course, through efficiency improvements in energy production and use. The stick is a carbon tax, an artificial price increase that works to drive technology to use less or find alternatives. The consumer will pay and this will move markets toward more efficient alternatives. The carrot is a subsidy, such as those for fermentation ethanol, that will allow an industry to build to a critical mass so as to become competitive...or not. Call it government directed capitalism. In my opinion, this works better than a "five year plan" or some such, as dictated by an undefined political structure that some on this board propose.