* that we should err on the side of caution is true, but isn't an answer. We already do, with the range of trials needed. And the opposition from anti-GM groups isn't "caution" any more than the denialism from the anti-IPCC folks is "scepticism". How useful are lessons like CFCs, or lead-in-petrol? In terms of GMOs I doubt they are useful, because people are already aware of them. it isn't as if people haven't desperately striven to prove GMOs dangerous.To which Eli notes that although we are increasingly good at identifying first year problems, what CFCs and tetraethyl lead show is that there are still large issues with things that are decades down the road. Now Eli, the Weasel, and even KK are pretty well satisfied that there are at worst minor issues with the immediate effects of GMOs introduced to date, but accumulating ecological (such as increasing resistance to Round Up) and biological issues are only now emerging and who knows what the future holds. DDT, Vioxx, estrogen therapy are examples of such accumulating issues. DDT and halons are particularly interesting in this regard. They show that once aware of these types of problems, use can be modified from broadcast use to niche, but vital applications.