The article provides an in-depth analysis of the development and utilization of hydrogen energy in the context of climate change and green energy transformation. It reviews green hydrogen policies in the United States, the European Union, Japan, and China, emphasizing the importance of renewable energy electrolysis in hydrogen production. The focus is on storing intermittent renewable energy and supplying green fuel across various sectors. The article discusses the technological progress of hydrogen production from wind and photovoltaic power generation. It highlights the environmental, social, and economic benefits of different hydrogen production routes, categorizing hydrogen into grey, blue, and green based on carbon emission intensity. The shift towards green hydrogen, produced from renewable energy sources, is seen as a positive trend for reducing carbon emissions. The article also outlines the predominant global methods of hydrogen production, with a significant portion coming from fossil fuels, especially in China where coal-based hydrogen production is prominent. Policy advances in developed countries and regions are examined, showcasing their early adoption of hydrogen energy. The potential of green hydrogen to create jobs, reduce carbon dioxide emissions, and contribute to the global energy supply is highlighted. The article concludes with a prospective analysis of the impact of renewable energy electrolysis on the global energy landscape and identifies key areas for future research and development in the field.