Toronto Sun: Growing concerns about climate change and peak oil have car manufacturers scrambling to find greener and more sustainable ways to fuel the world`s estimated 750 million automobiles. If trends continue, that number is expected to double in the next 30 years. Hydrogen was once considered to be the forerunner to replace gasoline as a primary fuel, but most auto manufacturers have dropped plans to develop a hydrogen vehicle because the costs are simply too high. General Motors CEO …