A recent study led by Geoffrey Ellis from the US Geological Survey reveals the presence of trillions of tons of geologic hydrogen beneath Earth's surface, offering a promising renewable energy source. The research estimates around 6.2 trillion tons of hydrogen exist within rocks and reservoirs worldwide, with some existing in locations like Albania and Mali. Although the reserves could be substantial, many are located deep underground or offshore, making extraction challenging. However, this geologic hydrogen is seen as a low-carbon energy alternative, with potential to meet global demand for centuries if harnessed efficiently. The study highlights the vast energy content of this hydrogen compared to natural gas reserves, emphasizing its sustainability. While the results are optimistic, experts like Prof Bill McGuire caution that large-scale extraction would require a massive worldwide effort, which may pose a challenge in addressing climate emergency swiftly.