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- James N. Siedow
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- doi: http://dx.doi.org/10.1104/pp.126.1.20Plant Physiology May 1, 2001 vol. 126 no. 1 20-22
James N. Siedow
Recent issues of Plant Physiology have contained a marvelous series of essays dealing with issues and controversies that surround the introduction and use of crops developed through the application of recombinant DNA technologies and genetically modified organisms (GMOs). These articles have provided considerable insight and thoughtful analysis of some of the major issues related to this timely topic. Among the points raised throughout these essays is the important role that GMOs will play as one of the components needed to enhance future agricultural productivity. Continued improvements in crop quality and productivity are crucial if we are to be in a position to feed the world of 10 billion people that will come into existence sometime after the middle of the current century.
In the first essay in this series, Chris Somerville admonished plant biologists to make their voices heard in the ongoing GMO debate. However, plant biologists who make their voices heard on this issue, and that should include every member of the American Society of Plant Biologists, need to be knowledgeable on many aspects relating to GMOs, a number of which go beyond the science involved. One difficulty with many plant biologists in this regard is that we know a lot about the biology but often much less about the agricultural, sociopolitical, and economic issues that bear on the discussions surrounding GMOs. This is particularly true when talking about GMOs in terms of world agriculture. I will admit to having been relatively ignorant of agriculture worldwide myself until several years ago when I first read the book written by M.J. Chrispeels and D.E. Sadava,Plants, Genes and Agriculture, which remains an excellent primer on the topic. Recognizing this general deficiency, I would like to recommend three books to anyone interested in the larger topic of feeding the world's population and in particular to those of you who are publicly engaged in the GMO debate.
The first book, Feeding the Ten Billion: Plants and Population Growth, is written by Lloyd T. Evans. Evans is a crop physiologist from Australia and takes the interesting tack of following the progressive development of agriculture through time, going from a population of five million about 10,000 years ago, to the six billion reached a couple of years ago. Evans notes at the outset that the book is not meant to be an all-inclusive history of agriculture, and it is not. However, much agricultural history is woven throughout the fabric of the text in a very readable fashion. Evans also does a good job of illustrating how advances in our understanding of plant biology have been incorporated into agricultural practices. It is interesting that although plant physiology began to be applied to agriculture in a knowledgeable manner in the first half of the 19th century, until the advent of the Green Revolution after 1960, the major contributor to increases in the world food supply was the extension of arable land. Increased production since then has been obtained through rising yields, a feature that is beginning to show some signs of slowing down.
The subject of arable land provides an illustration of why Evan's book is worth reading. I have often seen it stated that most, or even all, of the arable land on the earth is already under cultivation, suggesting there is no more land available for that purpose. Worldwide, this is not true, but the actual situation is complex. There is a lot of potentially arable land that is currently not under cultivation but much of it is undisturbed forest and wetland, whereas other land is arable but marginal. Arable land is being lost all the time to urbanization and replaced with previously uncultivated land, keeping the total roughly constant. The book is filled with topics like this that will help the reader better understand the complexities of the issues related to producing enough food to keep up with population growth. Most plant biologists should come away from reading this book with a better sense of world agriculture in terms of where we are today, how we got there, and the constraints that will drive its development over the next 50 years.
In a more philosophical vein, Evans begins the book by juxtaposing two views of the relationship between food production and population growth. The one view of Thomas Malthus has the supply of food being the driving variable and population growth dependent upon it and the other view is of Ester Boserup, who sees it the other way around, with population growth being the driver of agricultural development. Evans makes no attempt to resolve this issue, but keeps it front and center throughout the book and leaves it to the reader to ascertain which view might be closer to the truth. I would note that the correct answer, if one truly exists, would have a large bearing on the eventual acceptance of genetically modified crops, particularly in developing countries.
The second book I recommend reading is Feeding the World: A Challenge for the Twenty-First Century by Vaclav Smil. Although the title is similar to that of Evans' book, the approach is quite different. Smil brings more of an ecological perspective to the topic and treats the subject from the standpoint of where we are now and where we need to go in the future. Smil has long addressed issues of sustainability. The often-quoted limit of four billion people that can be sustained if nitrogen were only applied following the principles of organic farming can be traced to him, although others have made similar calculations. Smil's book makes for good reading because he regularly searches for practical approaches (or as he calls it, “truth”) to achieving a sustainable agriculture that can support 10 billion people. It is interesting that he does this in part by appropriating the most legitimate points of both those who see only catastrophe on our present course and those who effectively see no limits to the number of people that the earth can sustain long term. As he does this, Smil also points out fallacies associated with many of the numbers that both of these camps regularly cite.
As noted, Smil's goal is how to achieve long-term agricultural sustainability. To do that, he works his way up the food chain, from crop productivity through postharvest losses and onto food production, consumption, and human nutrition. In the process, he continually presents a message that there is considerable slack in the current system and that the prospects for more efficient use of existing resources at all levels are very real. Smil's background in ecology and his understanding of food chains shows up well in his discussion of nutrition and how an omnivorous world can be sustainable, but only if done in an intelligent way, which means more chicken and much less beef. It is equally important that the efficiencies Smil envisions are achieved with existing technologies and knowledge bases, although some of his approaches to optimizing plant physiological parameters are based on more ideal control of plant functioning than is presently attainable. The use of GMOs, pro or con, garners little mention. Far from being a drawback, this omission makes the book all the more important to read. It serves to remind us not only that GMOs are just one part of the solution to feeding a 10 billion-person world but also identifies what other components of the solution are likely to be.
Smil's movement from Evans' primary focus on agriculture onto issues of ecological sustainability and nutrition represents a good segue into the third book, The Doubly Green Revolution: Food for All in the 21st Century by Gordon Conway. Conway is currently President of the Rockefeller Foundation and was the recipient of the American Society of Plant Physiologists' (ASPP) Leadership in Science Public Service Award last year. Although Conway is cited as being an agricultural ecologist, there is clearly a lot of economist in him. This makes for tough sledding in some parts of the book. On the other hand, this also leads to a wealth of interesting and useful data presented throughout the book. Conway has spent much of his career working with the international agricultural research centers, and he provides a more detailed picture of the world agricultural scene than either of the other two books. He also understands poverty and the many socioeconomic factors that contribute to the existence of significant numbers of underfed people in a world of sufficient food supplies. Opponents of GMOs often use this fact and point to poverty as the problem, not a lack of food. Conway makes it clear that, however true the latter is, alleviating poverty is not a practical or workable solution and does not address the future need to feed 60% to 70% more people than exist at present.
Conway sympathizes with Smil's goal of achieving a more sustainable form of agriculture than that he sees associated with the first green revolution; hence, the notion of the next one being “doubly green.” He approaches this goal with several themes that appear regularly throughout the book. One is that he is much more supportive than Smil of the need to include new technologies in the mix needed to feed a world of 10 billion people. In that regard, GMOs (plants and animals) are addressed specifically, with Conway seeing the potential gains from the application of GMOs as far outweighing their perceived risks at this point. This is especially true when he talks of pest and disease management, where Conway envisions GMOs as being an important way out of the cycle of large-scale application of pesticides associated with the first green revolution. Conway also sees the need for far more broad-ranging partnerships than currently exist. He cites several examples where industry has either partnered with, or given technologies to, public agricultural research centers in developing countries. Conway is particularly upbeat about the possibility of companies acting as stewards of their technology in a way that benefits developing countries and protects their intellectual property rights in developed countries. However, this is not the only kind of partnership Conway envisions and another recurring theme is the need to empower and include local farmers in the new partnerships. He feels there is much to be learned on the ground from people who have spent decades or even centuries growing crops and surviving on a particular plot of land. In the end, Conway is calling for a comprehensive agricultural revolution, one that includes the technological, the ecological, and the sociological. He recognizes this will not be an easy task to accomplish but sees the cost of a failure to act as being extremely high. This book is the most difficult of the three to read, but I believe the reward is worth the effort to those who persevere.
In summary, all three books are built around the same general theme: feeding the world in the middle of this century. Although there is much overlap in what they have to say, each tends to emphasize a different area when looking to the future. Evans looks more to the capabilities inherent in the biology of plants, Smil stresses a more environmentally based approach and the need to optimize our use of resources to achieve agricultural sustainability, and Conway brings the socioeconomic and cultural dimensions of the world food supply more to the fore. In total, these three books make for informative and important reading for any plant biologist.
Before ending this essay, I would like to add a couple of my own thoughts related to the GMO debate and why the information provided in these three books is important for any plant biologist participating in that debate to know. First, in spite of their different outlooks, all three would agree that feeding a world of 10 billion inhabitants cannot be accomplished without making significant changes, particularly in the developing world, that run throughout the food chain, from agricultural quality and productivity to socioeconomics. However, the battle over the application of GMO technology to help feed the earth's growing population currently rests in the hands of the developed countries, whereas most of the people that will need to be fed are located in developing nations. The irony of this situation rests on the fact that thanks to modern agricultural practices, the population of the developed world has access to the most abundant, healthiest, and cheapest supply of food in the history of the human race. Simply stated, people in the developed world are spoiled when it comes to food, and they are in a position to be picky about what they chose to, or choose not to, eat. Opponents of GMOs do not need to prove whether any claim about the possible dangers of GMOs is true or not. Just raising the specter of a possible risk associated with GMOs in many people's minds is enough to make them say they do not want to eat any food containing GMOs. This decision is easily made because it comes with no apparent consequence for the cost, availability, or quality of the food they subsequently eat. That luxury is not afforded to someone in a country where food is nowhere near as cheap and available, as all three books make abundantly clear.
Second, as a long-time member and recent Chair of ASPP's Public Affairs Committee, I believe the Society can justifiably be proud of the extent to which members of the Public Affairs Committee and the Society as a whole have been willing to participate in the public debate on GMOs. In doing so, we have attempted to behave as honest brokers, ensuring that the scientific issues underlying the GMO debate are presented in as fair and objective a manner as possible. This is not always an easy thing to do when it comes to GMOs, given how polarizing the issue is. It has become difficult to take a position that remotely feigns in the direction of one side of the GMO issue without immediately being seen as some sort of mindless lackey by people on the other side. The best way I know of to counter the latter charge is to develop support for one's arguments (pro or con) based on a thorough understanding of the subject. Knowledge truly is power in this case, and one can never be too knowledgeable on this most controversial, current, and important of topics. Just as Chris Somerville opened this series of essays with a call for plant biologists to make their voices heard, I would like to end the series with a second important recommendation: “Go read a book (or three).”
LITERATURE CITED
For further details log on website :
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