evidence: In the years since the 5th Assessment Report, the uncertainty has grown. The latest climate model results – prepared for the forthcoming IPCC 6th Assessment Report – shows that a majority of the climate models are producing values of ECS exceeding 5oC. The addition of poorly understood additional processes into the models has increased confusion and uncertainty. At the same time, refined efforts to determine values of the equilibrium climate sensitivity from the historical data record obtain values of ECS about 1.6oC, with a range from 1.05 to 2.7oC. [...] 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.