The use of hydrogen as an alternative energy source is very promising mainly because it is considered a fully environmentally-friendly alternative fuel. Although no CO2 is produced by its usage, hydrogen production does emit greenhouse gases and use substantial amounts of energy. On the other hand, there are significant losses during production, distribution and utilization of hydrogen, that result in the release of considerable amounts of hydrogen in the environment. This study focuses on the environmental aspects of the entire hydrogen chain to investigate the overall effects of a global hydrogen economy on the environment. Since hydrogen should be preferably produced from a non-carbon source (no greenhouse gas emissions), the use of renewable energy sources instead of conventional fuels is proposed.