In the Guardian, John Abraham describes a new paper (.pdf) he co-authored that takes skeptic scientists Spencer and Braswell to task for having "made a number of basic math and physics errors" in an already weak study.
Spencer and Braswell created a model claiming it shows how standard climate models overestimate the amount of warming carbon dioxide causes. While the standard models do their best to capture all the nuances of the Earth's complex systems, Spencer and Braswell took the opposite approach. They simplified the planet into one big ocean (as though land masses didn't exist) and then simplified the oceans (failing to capture how water flows within the ocean.)
But even with all this (over)simplification, they couldn't get the math right! Abraham's post gets into the details, which are technical but by no means arcane or minor, and goes on to describe the situation as "the sort of thing that could have been avoided by consulting any elementary textbook on heat transfer."
That Spencer has produced yet another shoddy study shouldn't be that surprising. This is because he is notorious for being half the duo that had to correct their satellite temperature measurements repeatedly through the '90s and '00s, mostly as a result of others calling out their errors.
But in their defense, at least this paper wasn't so bad the journal's editor resigned,as was the case with a previous Spencer and Braswell study.