A straightforward definition from Wikipedia:
Green revolution refers to to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1960s, that increased agriculture production worldwide, particularly in the developing world, beginning most markedly in the late 1960s. The initiatives, led by Norman Borlaug, the "Father of the Green Revolution" credited with saving over a billion people from starvation, involved the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.
Can we agree that this was, on balance, a good thing? You know, kinda like the industrial revolution. Yes, the latter created new problems that had to be addressed--there were pros and cons--but would you rather go back to living in a pre-industrial society? The same holds true for the green revolution. It's fine to acknowledge its downsides, as Robert Zeigler, director general of the International Rice Research Institute, does here in the current issue of Cosmos magazine:
By the late 1970s and early 1980s the shortcomings of the early phase of the Green Revolution were becoming clear. The most serious were overuse of pesticides and fertiliser and the inevitable transformations of the rural sector where many, many gained but some, especially those in marginal environments, lost out.
This led to a reassessment of the Green Revolution's legacy in various circles. Zeigler notes:
A backlash began among leftist academics who viewed the Green Revolution as a way for capitalist governments and multinational corporations to subjugate small farmers. This view was helped by the fact that some oppressive West-leaning governments were avid champions of the Green Revolution. As the worst examples of the Green Revolution’s side effects became manifest, environmental concerns became part of the mainstream consciousness, culminating ultimately in the United Nations Rio conference of 1992. But that conference framed a false dichotomy that continues to this day, between a healthy environment and idyllic, contented farmers on one side and a high yielding agriculture on the other.
Those who viewed the downsides of the Green Revolution through a certain ideological lens would go on to oppose new beneficial agricultural technologies. As Zeigler observes,
the strange brew of anti-corporate sentiment, extreme environmentalism, romanticised traditional organic but land-hungry agriculture and fear of new technologies boiled over to create a powerful anti-technology backlash. The extreme regulations for GMO crops demanded by self-proclaimed protectors of the environment, had the perverse result that only the largest multinationals could afford to develop such crops. Predictably, this resulted in the same camp denouncing the growing domination of agriculture by multinationals. As costs for developing crop varieties escalated, the few seed companies that could afford the work focused only on areas with large markets. The marginal farmers were once again excluded. This time, though, who is to blame?
It's fine to debate the legacy of the Green Revolution. But we should also be clear-eyed about the legacy of the anti-GMO movement, which is already becoming clear.
