In 2008, Mark Lynas, an environmental activist, was unsparing in his criticism of genetically-modified (GM) food companies, calling their claims that GM crops could feed the world "outlandish" and dismissing arguments that they could better cope with the impact of climate change "a new line in emotional blackmail".

In his speech at the Oxford conference on January 3rd, Mr Lynas was no less uncompromising. "We will have to feed 9.5 billion hopefully less poor people by 2050 on about the same land area as we use today, using limited fertilizer, water and pesticides and in the context of a rapidly changing climate." The only way of squaring this circle will be through the technology-driven intensification of farming—i.e., GM.

Tom Macmillan of the Soil Association, which promotes the practice of organic farming, dismissed his views and said that popular opposition to GM crops is still strong and that GM crops require extra herbicides and dearer seeds while producing more resistant weeds and pests.

Mr Lynas's speech spotlights a growing tension within the environmental movement over how far to embrace technologies that have environmental benefits, when they work, but which raise fears of environmental disaster if they don't. Mr Lynas makes the point that greens are happy to accept scientific findings when it comes to climate change, but dismiss them as biased when they attribute benefits to GM.

Mr Lynas's speech also added intriguing twists to an old debate. As he pointed out, regulatory delays introduced as a result of anti-GM movements are getting longer. Many GM crops have been waiting a decade or more for approval. And this has a cost. Mr Lynas quotes figures from Crop Life, a Brussels based agricultural-technology association, which show that it now costs $ 139 to move from discovering a new crop trait to full commercialization. That means only big companies can afford to do it, says Mr Lynas: "anti-tech campaigners complain about GM crops only being marketed by big corporations when this is a situation they have done more than anyone to help bring about."

Once, criticism of GM crops advanced on all fronts: these things were unnatural, an abuse of science; they would spread rogue genes uncontrollably; they would be bad for human health and so forth. The scientific fears have so far proved groundless and opponents seem to be playing upon them much less—at least to judge by the narrow sample of criticism of Mr Lynas's speech. The main burden of complaint now seems to be that GM technology is a product of large companies which are unresponsive to public concerns. There is obviously much to be said for and against that charge. But for the moment it is worth noting two things. First, how much narrower the complaint is than the anti-GM criticism of only a few years ago. And second, as Mr Lynas himself points out. how much critics of the technology have themselves contributed to the dominance of large firms, by raising the cost of developing GM crops so high.