claim: the temperature increase in the second half of the 20th century could have taken place in steps driven by major ENSO events ( Jens Raunsø Jensen )
evidence: The average global temperature on Earth has increased by about 0.8° Celsius ( 1.4° Fahrenheit ) since 1880; Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20 °C per decade.