These data are from NASA's Goddard Space Research Institute.
From 2016 to 2018, the two main stages of short-term cooling led to the change of global temperature. The period is from February 2016 to June, the largest decline in five months in history and another from February 2017 to June.
In 2013 and 2014, it is said that the earth is entering a global cooling down period. It is expected that this period will continue to the middle of this century.
A former space shuttle engineer and NASA advisor even published a book in 2014, predicting that the world will suffer 30 years of cold wave attacks.