When it’s released directly into the atmosphere, hydrogen itself can interact with other gases and vapors in the air to produce powerful warming effects. Indeed, a new UK Government study has put these interactions under the microscope and determined that hydrogen’s Global Warming Potential (GWP) is about twice as bad as previously understood; over a 100-year time period, a tonne of hydrogen in the atmosphere will warm the Earth some 11 times more than a tonne of CO2, with an uncertainty of ± 5.