February 1, 2006 View all publications What the EU needs to do next to win the battle against global warming PDF 419.50k | Download Now The Kyoto Protocol, which entered into force on 16 February 2005, is the only legally binding international treaty to limit greenhouse gas emissions, mainly carbon dioxide (CO2). Over the past decade, governments met regularly to negotiate the detailed rules of the Kyoto Protocol that was agreed in the Japanese city in 1997.