Our current numbers of some six billion have already placed dangerous burdens on the ecosystems of spaceship earth and threaten our bio-diversity on which we are all interdependent. Global warming may indeed be global warning. So ploughing up wilderness to feed these extra people is no option. We can also eliminate organic farming as a meaningful solution. Organic farmers rely ultimately and only on soil nitrogen fixation to provide the essential nitrate and ammonia for crop growth and yield.
Rainwater provides the other minerals.
Since the maximum yields of fixed nitrogen have been measured numerous times we can estimate that by taking another 750 million ha of wilderness under the plough we could feed just three billion. But this option is now exhausted. Ignoring the problem, leaving billions to starve in misery, the worst of all tortures according to Amnesty International, is not an option either. So where one grain grew before we now again have to ensure that two will grow in the future. Currently GM is our best option to achieve this difficult task.