evidence: The recently published Intergovernmental Panel for Climate Change (IPCC) Synthesis Report, says "it is unequivocal that human influence has warmed the atmosphere, ocean and land", and warns that the Paris Agreement goals of 1.5°C and 2°C above pre-industrial levels will be exceeded during this century without dramatic emissions reductions. In reaching this conclusion, it is important to distinguish between changes caused by human activities altering the atmosphere’s chemistry, and climate variability caused by natural factors. [...] Current rates of global warming are unprecedented in more than 2,000 years and temperatures now exceed the warmest (multi-century) period in more than 100,000 years. Global average surface temperature for the decade from 2011-20 was about 1.1°C higher than in 1850-1900. Each of the past four decades has been warmer than any preceding decade since 1850, when reliable weather observations began.