Norman and Taylor, in "The Great Domaines of Burgundy" (3rd ed 2010) say in their glossary that these two terms are basically interchangeable. Jasper Morris, "Inside Burgundy" (2010, what an amazing tome!) says essentially the same -- his glossary entry for Climat is "a named area of vineyard"; for Lieu-dit, he says "A named place, or vineyard, almost interchangeable with climat."
The relatively new book (in French, which I read poorly) "Climats et Lieux-Dits des Grands Vignobles de Bourgogne" (Sept 2012), by Silvian Pitiot & Marie-Helene Landrieu-Lussigny, obviously draws a distinction -- to the point of providing separate (excellent) full page maps side-by-side for each village, one labeled "climats" and the other "lieux-dits," showing slight changes one from the other in vineyard names. (And yet as mentioned in Morris's book, his (great) maps originate from the same maps by Silvian Pitiot & Pierre Poupon that are apparently the source for the recent Climats et Lieux-Dits book.) Can someone shed light -- what is the distinction in these two terms, especially as so carefully highlighted in the recent book? I infer from some of the maps in the Climats et Lieux-Dits book that climats are a more precise subset of lieux-dits? Thanks -- Jake