Carbon dioxide emissions contribute to rising average surface temperatures and the melting of arctic sea ice as well as ocean acidification, threatening precious natural habitats like coral reefs. In 2014, the Intergovernmental Panel on Climate Change (IPCC) predicted with 'high confidence' in its fifth assessment report that, even in the case of moderate global warming, many regions in the world would experience more extreme weather events in the future. Moreover, a rise in the average global temperature of around three per cent would lead to 'extensive biodiversity loss' . 1 The report outlined two extreme scenarios: one, a 'low-emission mitigation scenario' , in which states worldwide reduce their emissions substantially and take coordinated systematic action to control their impact, limiting the rise in temperature to 2.6 degrees centigrade during the period from 2081 to 2100 (compared to the mean temperature between 1986 and 2005); and, two, a catastrophic 'high-emission scenario' with a temperature rise of 8.5 degrees centigrade in the same period. 2 The fifth IPCC assessment report resulted from a global effort since 2008 to collate and interpret scientific data on climate change. A total of 259 authors from thirty-nine countries debated the physical science base of climate change, receiving 54,677 comments in the process. A total of 309 authors from seventy countries analysed issues regarding the impact of climate change, adaptation to its consequences and the vulnerability of different human societies, considering 50,444 comments in the course of their work. Finally, 235 authors from 57 countries devoted themselves to identifying ways to mitigate climate change, incorporating 38,315 comments. 3