One of the papers cited in support of this is the analysis of weather balloon data by [Gaffen et al, 2000], which covers the period 1960 to 1997. (realclimate.org)
So a peek at the satellite (and weather balloon data from the same layer) will show 1) just how much of 2015's warmth is because of El Niño, and 2) just how bad the match is between what we're observing and the temperatures predicted by the current (failing) family of global climate models. (cato.org)