Mitigation of environmental impacts and challenges during hydrogen production

[Display omitted] •Environmental impacts and their mitigations for various H2 production techniques.•Prospects, government plans, and policies related to energy and H2 production.•Merits and demerits of different H2 production techniques.•Transition to biohydrogen production with the corresponding merits and challenges. This paper presents hydrogen production methodologies, their impacts on the environment, and mitigation. Three different types of production procedures, namely fossil fuel-based, renewable energy-based, and biological, are presented along with their key technological characteristics and environmental feasibility. The effects of greenhouse gas emissions from its production on different natural cycles are carried out to show the environmental impact. Different production methods, problem identification, and mitigation of environmental impacts are separately pointed out. Analyses are shown for available methods in terms of their production cost, efficiency, maturity level, advantages, problems, and solutions. A comparative analysis is carried out along with different existing methods to find a suitable H2 production method. Finally, the transition pathway from fossil fuel to biohydrogen production is intended to promote biohydrogen for transportation and industrial applications. It demonstrates the possibility and potentiality of biohydrogen production for a sustainable future.