Sir

Jonathan Latham1 in Correspondence states that famine is a problem of global food distribution and arable efficiency rather than of food quantity, and that hence there is no need for genetically modified (GM) crops. Although this argument may in theory apply today, it will not in practice apply tomorrow.

Of course there are scientific questions that still need to be answered about GM technology, but we already know that by the middle of the twenty-first century the world is going to face a food crisis, and that agriculture will consequently put increased pressure on wildlife habitats.

In 1998, the UK Institute of Biology and six affiliated societies (whose specialist interests range from agricultural production to ecological conservation) produced a report on the social and ethical aspects of GM crops2. We cited half a dozen indicators of the forthcoming shortfall in global food supply, including the following. Forty per cent of terrestrial primary productivity is already managed by humanity. The trend for the past 15 years has been a reduction in grain production per capita. Global sea-fish catches have been in steady decline since 1990 because of over-fishing. World carry-over stocks of grain are declining from one year to the next. The grain harvest area per person has been declining since the late 1970s, owing to increasing population, growth in industry and desertification.

The increasing consumption of meat in the rich nations has put more pressure on the poor, although reversing this trend alone (even if it were realistic) would not counter the pressures caused by a population increase of 40 to 80 per cent over the next four decades. The world shows no sign of turning vegetarian. Although I am sympathetic to Latham's conclusion that “what is missing is the ‘purchasing power’ of the poor”, the evidence is that when the poor become a little richer they eat more meat.

Given that agricultural inefficiencies and global inequalities are bound, sadly, to continue, it is likely that genetic modification where appropriate will make a significant contribution to human well-being — and to that of other species.