It is helpful to update and evaluate temperature data occasionally.  Accordingly, I have done so in the chart below, using data maintained by the Goddard Institute of Space Studies (part of NASA).  The data are actually collected by National Oceanic and Atmospheric Administration (NOAA).  This collection of data extends from 1880 and is typically cited as providing the most reliable surface temperature anomalies available and is available here.  While it has serious flaws, it is the best available and has been cited by NASA and quoted in the Washington Post as demonstrating 2016 to be the warmest year on record, with each of the first six months setting new records (see red below).  But notice that the heating had begun in late 2015, a period that coincided with one of the strongest El Niños on record, and arguably explains the spike in temperatures in early 2016.  By 2017, temperature anomalies had dropped significantly, with the first five months being about average over the last six years.  In total, temperature anomalies were below year-previous levels for a total of 20 consecutive months, from October 2016 through May of 2018.

Those who failed to emphasize the importance of El Niño in heat spikes were guilty of serious malfeasance.  But that has been the story of climate "science" at least since Michael Mann and others spliced several sets of data together, much of it "proxy" data – tree rings, ice samples, etc. – in order to get a long time series that would show a "hockey stick" effect in recent years.  Climategate demonstrated the full depth of corruption, with emails revealing collusion among many involved.

A 123-page paper by Christopher Booker, published by the Global Warming Policy Foundation (GWPF), explains how a few strong personalities formulated and perpetuated what amounts to a hoax.  The first of these was a Swedish meteorologist, Professor Bert Bolin (1925-2007).  Bolin presented his views in 1979 at a first-ever meeting of the "World Climate Conference," sponsored by the World Meteorological Organization (WMO), a 191-member-country agency of the U.N. headquartered in Geneva, Switzerland.  Six years later, Bolin presented a longer paper for a 1985 conference in Villach, Austria, in which he concluded that "human-induced climate change" called for urgent action at the "highest level." 

An attendee who became convinced was Dr. John Houghton, a former professor of atmospheric physics at Oxford, who had been head of the U.K. MET since 1983 and was founder of the Hadley Center in 1990.  He would be the lead editor of the first three reports (1990, 1996, and 2001) of the Intergovernmental Panel on Climate Change (IPCC).  The IPCC was established in 1988 by two U.N. agencies, the WMO and the UNEP (United Nations Environment Program).  The UNEP was founded in 1972 by Maurice Strong as a result of the U.N. Conference on the Human Environment held in June 1972. 

Strong was a Canadian self-made billionaire in the energy and carbon trading business, having founded the Chicago Carbon Exchange, among other endeavors, who once self-identified as a "socialist in ideology, a capitalist in methodology."  He became greatly involved in U.N. activities and influenced the Stockholm Conference through a 1971 report he commissioned on "the state of the planet," a summary of findings of 152 "leading experts from 58 countries."  A December 2015 Breitbart article described Strong as a "totalitarian control freak" for his expressed desire to deny national sovereignty to achieve "global environmental co-operation" through the transformation of the U.N. into a world government.

So one is left with the impression the whole scam was concocted by a small number of "one-world government" types, socialists, and crooked scientists, with the aim of transferring trillions of dollars out of industrial countries.