Conclusion
Several thermochemical and kinetic factors make hydrogen attractive as the next industrial and transportation fuel. The wide flammability limits allow lower or comparable pollution emissions to carbon based fuels (methane). The additional problems of organic pollutants such as carbon monoxide, formaldehyde, sulfur (acid rain), and lead are eliminated with a H2-air combustion system. If the hydrogen is derived from a solar-hydrogen array, then problems of erosion and mining could be eliminated from coal production. In the era of the environment, where pollution and greenhouse gases are devaluing the quality of life for many on the earth, hydrogen poses a possible solution to our thirst for chemical fuels for transportation and goods.

Will the solar-hydrogen economy ever become a reality? The 400 billion dollars in equity in petroleum and gas exploration along with the coal industry signals that the transition will take a long time, as not to shock the present carbon-combustion economy. If the world starts today to take a pledge for change, as did several scientists and engineers in the Energy-Environment Resolution, when the supply or fossil fuels is still in full swing, the change over will be smoother, and we could all breath a little better.