Transition to the hydrogen energy economy is justified from environmental and energetic viewpoints, its cost is estimated, and various means to finance it, including various synergies, are discussed. Planetary sources of renewable energy (wind, water, sun) are estimated and deemed sufficient to more than replace all fossil fuel. Cost and magnitude of required infrastructure then imply long construction times during which pollution and global warming may have time to become unacceptable. Advantages of energy as a transition facilitator which avoids them are examined, along with means to alleviate public anxieties about its use. The conclusions are that the main obstacles to a healthy hydrogen-based world are less scientific, technical or economic than due to inertia, ignorance, blindness, stupidity, fear and mistaken narrow interests, and that there will be enough time to overcome them if we attack the problems more energetically and each other less so.
