I want to start with some apologies. For the record, here and upfront, I apologise for having spent several years ripping up GM crops. I am also sorry that I helped to start the anti-GM movement back in the mid 1990s, and that I thereby assisted in demonising an important technological option which can be used to benefit the environment.

As an environmentalist, and someone who believes that everyone in this world has a right to a healthy and nutritious diet of their choosing, I could not have chosen a more counter-productive path. I now regret it completely.

So I guess you’ll be wondering – what happened between 1995 and now that made me not only change my mind but come here and admit it? Well, the answer is fairly simple: I discovered science, and in the process I hope I became a better environmentalist.

Knowing what we now know about living systems—how they replicate and how they mutate—we are beginning to know how to control their evolutionary futures. To a considerable extent we now do that with the plants we cultivate and the animals we domesticate. This is, in fact, a standard application of genetics today. We could even go further, for there is no reason why we cannot in the same way direct our own evolutionary futures. I wish to emphasize, however—and emphatically—that whether we should do this and, if so, how, are not questions science alone can answer. They are for society as a whole to think about. Scientists can say what the consequences might be, but they are not justified in going further except as responsible members of society.

TEN THOUSAND YEARS AGO, humans learned how to farm. It was an epochal invention that made possible settled life, cities, craft specialization, writing, organized religion, architecture, mathematics. science. Now humanity stands on the brink of a second agricultural revolution potentially as great as the one that occurred when our ancestors gave up hunter-gatherer way of life and settled down as farmers. Scientists and engineers are poised to genetically modify organisms to increase the yield, nutrition, freshness, and pest resistance of food plants and animals, and perhaps even to diminish the use of artificial fertilizers (and fossil fuels) by supplementing biotic nitrogen-fixation systems. Other possible benefits of genetically modified (GM) organisms include improved use of marginalized land—saving wild areas from the plow—and abundant production of vaccines and pharmaceuticals. possibly eliminating diseases such as cholera, hepatitis B, and malaria. The promise is great. But as always with the products of human artifice, not without attendant dangers.