This is quite shocking Joe.
Ruben Anderson

Hey Ruben,

I originally heard about this while researching world hunger two years ago, then did some digging using Google Scholar to search the research literature. This article from Nature provides a nice summary of the climate modeling study (PDF here):

Booth, B.B.B., Dunstone, N.J., Halloran, P.R., Andrews, T., & Bellouin, N. (2012). Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability. Nature, 484, 228–232.

This study from researchers at the University of Reading, UK provides additional support:

The impacts of European and Asian anthropogenic sulphur dioxide emissions on Sahel rainfall

Sadly, the linkages between recent advances in the climate science are not well known by science writers and journalists. Thus the absence of this huge story in the media. Hopefully more people will dive into the research literature and uncover more patterns like this in the future.

Hope this helps!