Still , there are some who are uneasy about a man who made millions in the oil business advocating clean energy :
In the last few years , he has often been on the Chronicle of Philanthropy 's list of top U.S. philanthropists .
There are some who are uneasy about a man who made millions in the oil business advocating clean energy :
In the last few years , he has often been on the Chronicle of Philanthropy 's list of top U.S. philanthropists .