claim: The consequences of climate change become increasingly bad after each additional degree of warming, with the consequences of 2°C being quite damaging and the consequences of 4°C being potentially catastrophic.
evidence: For example, in 2007 the Intergovernmental Panel on Climate Change (IPCC) projected a high end estimate of 60 cm (2 ft) through 2099, but their 2014 report raised the high-end estimate to about 90 cm (3 ft).