By Richard Black
Environment correspondent, BBC News website
The realities of food crops are more tangled than the Prince suggested
Prince Charles usually speaks from the heart; and his latest outpouring on genetically modified crops is expressed in terms that are forthright even for him.
Judging by readers' comments appended to the Daily Telegraph article outlining his position, he has struck a chord.
This should not be surprising. There are few, if any, such divisive subjects in the scientific firmament; and in the UK at least, polls show deep public suspicion.
But the prominence given to the Prince's words across a range of news media prompt the question: is he right?
While he is adamant that food supplied through genetic technologies would be "guaranteed to cause the biggest disaster, environmentally, of all time", he offers not a jot of evidence to support the claim.
GM agriculture is often treated as a single entity which must in its entirety be regarded as good or bad, healthy or unhealthy, environmentally benign or destructive.
In the real world, biology is rarely that simple.
The strains being grown commercially today remain products jealously guarded by the companies that market them
Take the example of gene flow, the spread of introduced genes from a GM plant into non-GM neighbours, either weeds or conventional crops
How likely it is to happen depends on many factors, among them the type of crop, how its genes may be carried (for example by insects), the way farmers manage it, the weather, and whether any related plants are growing nearby.
So even though it has been shown to occur in some situations - for example, between hybrid radishes grown on the farms of Michigan and wild radishes growing nearby - in others, it does not.
Even if gene flow is documented, it does not automatically cause problems.
And that is just one example of an isolated environmental question.
Everyone will have their own opinion about the risks involved; and humans are notoriously bad at assessing risk, as evidenced by a common instinct that driving is safer than flying.
But it is clear that if we look at what science tells us, the GM world is considerably more complex than the one Prince Charles has painted; and you can multiply the complexity a thousand-fold if you include all the environmental, social and economic questions.
But the Prince also had some harsh things to say about the modern system of food production and distribution.
Christian Aid is among groups blaming the global food trade for shortages
There were some apparent omissions and confusions. For example, the Green Revolution crops he mentions - the rice, maize and wheat hybrids developed half a century ago that sent yields through the roof in Asia and Latin America - were not products of genetic technologies but of conventional cross-breeding.
True, problems are now arising with the crops in some areas with water shortages - they are heavy on irrigation - and soil degradation. But the Prince does not mention that the Green Revolution changed India from a country that regularly needed liberal doses of food aid to one that was self-sufficient and food secure.
Nevertheless, many of the issues he raises - pressure on small-scale farmers, the hunger of modern farming methods for water, food security - are all too real in some parts of the world.
Food production, and more especially food distribution, are increasingly in the hands of giant multinational companies. Farming has already had its industrial revolution in developed countries, and the developing world is following suit.
For society and for the environment, this is a much bigger issue than whether those industrialised farms are growing GM or non-GM crops.
Both mean increased use of pesticides and fertilisers, the trading of machinery for human muscle and the consequent loss of labour compared to traditional agriculture.
GM crops have long been opposed by UK campaigners and the public
In Britain, where GM crops have never been widely grown, intensive farming has been a factor behind a wide range of environmental ills ranging from water pollution to biodiversity decline.
European and national schemes that encourage farmers to look after the environment are repairing some of the damage.
Perhaps the most telling comments on the Farm-Scale Evaluations (FSE), the biggest UK trial of GM crops, came after the event from environmentalists who said what was really needed was a trial of intensive versus non-intensive farming methods.
They could have added that such studies might not restrict themselves to environmental questions; it would also be worthwhile investigating social and economic questions, such as whether intensive or artisanal farming benefits the entire economy more, rather than specific players such as supermarkets, and trying to find some objective answers rather than relying on the theologies of rival schools of economics.
Would the uptake of genetically modified crops across the world make these issues worse?
Perhaps. There are conflicting studies from different areas - often prepared by institutions with a vested interest - showing that GM crops either produce higher or lower yields, need a higher or lower chemical input, and generate higher or lower profits for farmers compared to their conventional equivalents.
A few indisputable facts leap out, however. One is that commercial GM farming is dominated by four crops - soybean, maize, cotton, and canola - and has been wholeheartedly embraced by only a few countries, among them the US, China, Argentina and Canada.
Prince Charles has regularly made his views clear on GM crops
A second is that consumers in Europe do not want to eat GM food, which is one reason why farmers in the EU and in regions supplying food to Europe, especially Africa, are not going to be making a large-scale switch any time soon.
A third - and the one most pertinent to Prince Charles' argument - is that the people and institutions behind the technology have failed to deliver on promises to right their original wrongs and develop strains that would benefit people in poorer countries and loosen corporate control.
Almost exactly four years ago, I was in Cologne, Germany to cover the Agricultural Biotechnology International Conference (Abic). Scientist after scientist (many of them working in the commercial sector) told me how companies had messed up by appearing to force GM products on an unsuspecting world, and how narrow the lines of research had been.
A second wave of crops, they pledged, would bring things that people actually wanted and needed, from drought-resistant rice for Africa to vitamin-enhanced fruit for Europeans, and would largely use technologies that did not involve transferring genes from one organism to another.
On a commercial scale, these developments have not arrived.
Earlier the same year, at the Indian Science Congress in Chandigarh, I listened to Indian scientists from the president down explain how national research institutions were going to develop strains with traits such as enhanced nutrition and salt resistance, and give them away to farming communities.
That, also, has not happened.
The strains being grown commercially today have been engineered either to help farmers control weeds through proprietary herbicides or to reduce pest damage, and remain products jealously guarded by the companies that market them.
Against this backdrop it is perhaps not surprising that many commentators on Prince Charles' interview share his apparent view that GM crops would only add to the woes of farmers and the hungry in poorer countries.
But it is also possible to argue that as things stand, GM crops are irrelevant to the wider patterns of increased corporate control of food chains, the stubborn and enduring hunger felt by much of the developing world, and the global trend of environmental decline.