Science Source

Record Hot Year, 2015

Estimates the 2015 global temperature anomaly to be 1.05ºC (1.89ºF) above the 1850–1900 average that the IPCC takes to be “pre-industrial"
Determines the year 2015 is therefore likely to be remembered as the first year that two symbolic thresholds were set: the 1ºC (1.8ºF) temperature anomaly threshold and the 400 parts per million (ppm) CO2 threshold
Determines that of the 1.05ºC temperature departure from pre-industrial, roughly 1.0ºC is due to the anthropogenic forcing, about 0.05ºC (0.09ºF) to 0.1ºC (0.18ºF) is due to El Niño and about 0.02ºC (0.04ºF) is due to higher solar activity
Bases analysis on well-established techniques from the peer-reviewed literature (Foster and Rahmstorf, 2011; Suckling et al, 2015)