Some, including Internet encyclopedias, will point out that the "Green Revolution" began in the midst of WWII in the 1940s as scientists began to find ways to boost crop yields with the introduction of chemical fertilizers and then eventually genetically modified crops and other methods that came into being as time went on. This revolution arguably continues today as increasing yield is one of the major focuses of agri-business giants like Monsanto and others.
Others might argue that the "green revolution" started in the 1970's with Rachel Carson's "Silent Spring" and others that pointed out some of the dangers of the use of chemical pesticides and other side effects of pollution and an unwillingness to examine the consequences of our development and expansion and is an environmental movement rather than a crop-yield movement.
According to Walt Parks of the University of Georgia, "Green Revolution" was coined by William Gaud, Director of US International Development Agency, in 1968 to identify the effort to increase crop yields. Parks identifies the Green Revolution to be in an "aftermath" because of failures in the program and continued population increase.