2 degrees Celsius? What is still achievable in climate protection? Book launch and discussion in Berlin. The Kyoto Protocol, one of the most important climate protection treaties, came into effect in 2005. However, its goal of reducing carbon dioxide emissions as the main cause of increased global warming continues to pose a challenge for international politics. In industrialised countries, CO2 emissions are still rising. The question of what can be demanded of developing and emerging economies is, as yet, unsettled.