I believe that alternative fuel solutions will be widely used in the future because the resources we use now (coal, oil, natural gas) are all finite resources that the human race will completely use up. People seem to think these resources will be around forever and that is far from the truth.
Alternative fuel solutions are being used widely right now. More than ever before at any point in the history of the motor, in fact. We have so many new electric cars, hybrids, and vehicles that run on methane or other natural gases now. This is just the start, and more are on the way.
I don't think the world will adopt alternative energy sources until survival depends on it. There will come a day when society does depend on it, a day when mining fossil fuels is no longer cost effective. When that day comes we will be eager to exploit the possibilities of wind and solar and whatever other alternative energies are available.
I think that alternative fuel solutions are going to be widely used in the near future. I think that it is only logical to think that when a fuel alternative is found, a lot of countries are going to want to use once fuel resources are scarce. I think that alternative fuel solutions are the future.