evidence: Apart from the issue of how much greenhouse gases might increase, there is a great deal of uncertainty about much the planet will warm in response to a doubling of atmospheric carbon dioxide – referred to as ‘equilibrium climate sensitivity’ (ECS). The IPCC 5th Assessment Report (2013) provided a range between 1 and 6oC, with a ‘likely’ range between 1.5 and 4.5oC. [...] To further complicate climate model projections for the 21st century, the climate models focus only on manmade climate change – they make no attempt to predict natural climate variations from the sun’s output, volcanic eruptions and long-term variations in ocean circulation patterns. We have no idea how natural climate variability will play out in the 21st century, and whether or not natural variability will dominate over manmade warming. [...] We don’t know how the climate of the 21st century will evolve, and we will undoubtedly be surprised. Given this uncertainty, precise emissions targets and deadlines are scientifically meaningless. We can avoid much of the political gridlock by implementing common sense, no-regrets strategies that improve energy technologies, lift people out of poverty and make them more resilient to extreme weather events.