On the temperature graph in the SN article, there appears to be a dip in global temperatures starting about 1940 and bottoming out about 1960, after which the warming trend beginning around the turn of the century seems to resume. Temps do not rise to pre-war levels until around 1980. The data represented here is too coarse and too noisy to draw definite conclusions, but at first glance, it does suggest a response to the activities of WWII.

The blip right at 1960 could be due to the era of nuclear testing, but most of those tests were conducted underground or at sea, or in desert areas, and relatively few particulates and soot were projected into the atmosphere. Unless there was a major volcanic event at that time, my guess is it's just noise. Still, that post-war dip does stand out, even to the unaided eye.