23 January Researchers demonstrate a prototype 3D printer that can print fully functional human skin.[29] Scientists at the Scripps Research Institute create the first stable semisynthetic organism. This can hold two synthetic bases, called X and Y, in its genetic code indefinitely. The team says it could lead to entirely new life forms using synthetic DNA, with many potential uses in medicine.[30][31] 26 January Researchers at the Salk Institute create the first human-pig hybrid embryo, containing genetic information from both species.[32][33][34] Scientists at Harvard report creating a small amount of metallic hydrogen for the first time, a century after it was theorised.[35][36] The claim is disputed.[37] 27 January – A report from the EU's Joint Research Centre concludes that if global temperatures rise by 4°C, the flood risk in countries representing more than 70% of the global population and of the global GDP will increase by more than 500%.[38] 30 January – News reports that a new safe battery has been invented.