FAP, June 12 / PRNewswire-FirstCall-Asianet /-- an international research team led by scientists from the International Centre for Climate and Environmental Research (CICERO) in Oslo, Norway, published a paper in the June 7 issue of Communications Earth and the Environment, saying that the leaked hydrogen has almost 12 times the impact of carbon dioxide (CO_2) on global warming. This is the most comprehensive assessment of the climate impact of hydrogen to date, filling in the gaps in relevant knowledge. Research leader Maria Sander, a senior scientist at CICERO, pointed out that unlike burning coal and gases containing CO_2, burning hydrogen only emits water vapor and oxygen. Hydrogen is not a greenhouse gas, but its chemical reactions in the atmosphere affect greenhouse gases such as methane, ozone and stratospheric water vapor, so hydrogen leaked from production, transportation and use can contribute to global warming.