This paper will take a retrospective examination of aerosol-climate research since the beginning of the twenty first century. This is the period when MODIS data became available due to the intellectual leadership of Yoram Kaufman. The fundamental contribution of MODIS is that it retrieved aerosol properties over the land regions of the globe, in addition to that over the ocean. This enabled us to follow aerosol (dust, soot and sulfate) plumes from their source regions over populated regions, all the way across the oceans, thus establishing the major importance of long range transport of particles across the globe. By itself, this development would have had a major impact on the field; but Kaufman followed this up by using MODIS spectral data to partition aerosols into larger and smaller radius particles, which enabled us to make estimates of anthropogenic contribution to the total aerosol loading. The denouement was the setting up of the AERONET sites around the world (in collaboration with Brent Holben at NASA_Goddard) and the integration of MODIS satellite data with surface observations to yield for the first time a global picture of aerosols, the manmade contribution to the aerosol loading and first time estimates of aerosol single scattering albedo. These spectacular developments (over a 6 year period) enabled NASA-Goddard as well as scientists from around the world to gain new insights into a variety of fundamental climate problems including: estimation of the direct, semi-direct and indirect aerosol forcing of climate; long range transport of pollution; global dimming; excess or anomalous solar absorption; global solar radiation budget; and the role of aerosols in precipitation.