I was listening to a CPR interview with someone that wrote a book on the top 100 ways to reduce greenhouse gases but the more realistic and reachable ways to do so.  #1 reducing the use of HCFCs, primarily in refrigerant devices, which most developed countries have a road map for.  #2 was eating less meat, particularly beef, a this article points out.  She noted that if cows were their own country, they would be the #3 GHG emitter in the world.  #3 Was food waste, particularly wasting of food at the table in developed countries and the waste of food in supply line in developed countries.