Environment impact of hydrogen - a renewable source of energy

Environmentally harmless energy sources, like hydrogen, will become important in a future sustainable system based on renewable energy. Hydrogen is an important, though little studied, trace component of the atmosphere. It is present at the mixing ratio of about 510 ppb. Hydrogen is therefore an indirect greenhouse gas with a global warming potential GWP of 5.8 over a 100-year time horizon. A future hydrogen economy would therefore have greenhouse consequences and would not be free from climate perturbations. Our study focuses on the environmental impact of using hydrogen as a energy source. If a global hydrogen economy replaced the current fossil fuel-based energy system and exhibited a leakage rate of 1%, then it would produce a climate impact of 0.6% of the current fossil fuel based system.