You were likely referring to some of the recent work of Vincent Courtillot. A video summarizing some of his work here.
The most interesting aspect of this work, is that Courtillot did not start out with any intention of finding correlations with climate; his field is geomagnetism. Only after noticing certain correlations between geomagnetic cycles and sun spot cycles, did suspected correlations with natural climate cycles become evident.
You were likely referring to some of the recent work of Vincent Courtillot. A video summarizing some of his work here.
The most interesting aspect of this work, is that Courtillot did not start out with any intention of finding correlations with climate; his field is geomagnetism. Only after noticing certain correlations between geomagnetic cycles and sun spot cycles, did suspected correlations with natural climate cycles become evident.