I guess he was talking about soot and other aerosols. That's huge for air quality, but climate change is primarily driven by the fundamental law of coal burning: C + O_2 -> CO_2. If he managed to reduce the emission of sulfate aerosols (a likely target, since those are the primary cause of smog and acid rain) he is actually making the warming problem worse:
http://www.yaleclimateconnections.org/2008/06/common-climate...