IANAClimatologist. This[1] chart is not subject to the "missing data" problem; as cited by wikipedia it is composed from freely available data. In addition by including satellite data that is free of an entire class of measurement artifacts it substantially limits the plausible error alleged by the article. The
best interpretation of the article is that it is an astonishingly narrow picture of a small slice of an enormous field.
[1]http://en.wikipedia.org/wiki/File:Satellite_Temperatures.png