Global Policy Forum

Genetically Modified Crops and the

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By Matt Kallman

Earth Trends
June 17, 2008

As world food prices reach record highs, concerns over agricultural productivity are mounting. Productivity growth has stagnated as the world's population has continued to rise, and the wealth generated from economic development is further increasing demand for food. The use of food crops like corn and sugarcane for biofuels production exacerbates the situation. The United Nations estimates that agricultural output will have to rise 50 percent by 2030 to meet this increased demand (UN, 2008).

Policymakers, scientists, and farmers alike must find new and innovative ways to increase food production. This has been accomplished in the past: the "green revolution" of the mid-twentieth century more than doubled global food production through the introduction of pesticides, fertilizers, and high-yielding crop varieties. Today, confronted with increasing land and water constraints, technological innovation is again being looked to as a way to feed the world in a sustainable and nutritious manner throughout the 21st century. In this context, GM crops have experienced both rapid growth and extraordinary controversy in recent years, raising difficult questions about their future usefulness in global agriculture.

GM Technology versus Conventional Breeding

Plant breeders have been modifying the genetic makeup of crops for centuries. By selectively breeding individual plants within a single species, by cross-breeding plants from different but related species, or by inducing genetic mutations via chemicals or radiation, "conventional" plant breeders have promoted desirable traits to increase agricultural productivity.

Modern biotechnology and recent breakthroughs in DNA sequencing have introduced an increased level of precision to plant breeding techniques, opening up a new realm of possibilities for the genetic modification of plants and animals. Whereas conventional breeding requires the random transfer of thousands of genes within the constraints of sexual reproduction, so-called "genetic modification" involves the identification, isolation and transfer of specific genes between organisms, even if those organisms are not sexually compatible. For example, Bt corn—one of the most widespread GM crops in commercial agriculture today—expresses a gene from the soil bacterium Bacillus thuringiensis. GM Crop Trends Worldwide

As recently as a decade ago, GM agriculture was virtually non-existent, but has since expanded rapidly, both in terms of total area planted and the number of countries involved (see Figure 1). In 2007, farmers in 23 countries grew more than 114 million hectares of GM crops—mainly soy, maize, cotton and canola (ISAAA, 2007). Still, more than 99 percent of all GM crops are produced in only eight countries (see Figure 2). Furthermore, widely commercialized GM crops currently express only two traits: herbicide tolerance and/or insect resistance. Many of these GM varieties are patented by major biotechnology companies like Monsanto and Syngenta.

Figure 1: Growth in GM Crop Plantings, 1996-2005


Source: Brookes and Barfoot via ISAAA, 2006

Figure 2: Distribution of GM Crop Plantings in 2007


Source: ISAAA, 2007

GM crop use is concentrated in countries with highly industrialized, export-oriented agricultural sectors. The four most common GM crops are soybeans, maize (corn), cotton and canola. The United States is the top producer, with more than 57 million hectares of agricultural land planted with GM crops (ISAAA, 2007). An estimated 60 percent of processed foods in U.S. supermarkets contain at least one GM ingredient, usually soy, canola, or corn (Hopkin, 2001). A large percentage of crops in Canada, Brazil, and Argentina are genetically modified (see Figure 3).

In contrast, European countries have voiced the strongest resistance to GM agriculture, although the European Union has begun to relax restrictions on GM imports and domestic production is also on the rise. At least a dozen countries in South America, Africa, Asia and Europe prohibit the commercial planting of GM crops, although a few allow imports for food and/or animal feed.

Figure 3: GM Varieties Dominate Many Key Crops


Source: Brookes and Barfoot via ISAAA, 2006

Feeding the Future

The challenge in the coming decades will be to feed a growing global population, which is predicted to reach more than 9 billion by 2050 (UN, 2006). Much of this population growth will be in the developing world, where economic development will make people wealthier and will change their dietary needs. In particular, food demand from China, a major driver of the coming demographic boom, will increase. China, with more than 20 percent of the world's population, has only 7 percent of its arable land, and will need to expand imports or increase the yield of the crops it already grows (Walker, 2007).

Worldwide, very little land suitable for cultivation remains (Millennium Ecosystem Assessment, 2005), so the majority of this agricultural expansion will have to occur on existing cropland. The UN Food and Agriculture Organization predicts that 80 percent of the increase in agricultural production will result from improved crops and technology on existing agricultural land; the other 20 percent will result from expanding farming to already scarce land in South America and sub-Saharan Africa (FAO 2007).

An added imperative is that any second "green revolution" be conducted in a sustainable fashion, as agriculture is directly linked to critical environmental issues like climate change, biodiversity, and water quality and availability. Are GM crops a possible solution?

Potential Benefits of GM Agriculture

GM crops could potentially provide many health and environmental benefits, but their actual effectiveness is the subject of some scientific debate. Some potential benefits of GM crops currently in use include:

  • Herbicide tolerance: Herbicide-tolerant GM crops are able to withstand the chemical sprays that farmers apply to kill weeds. Planting genetically modified crops allows farmers to use wide-spectrum herbicides, rather than harsher weed-specific sprays that damage the environment and negatively affect human health. However, studies by the U.S. Department of Agriculture have shown that farmers using GM crops do not use fewer pesticide sprays, although some of these chemicals may be less harmful than those applied to non-GM crop varieties.
  • Insect resistance: Certain GM crops are engineered to produce their own insecticides, killing pests while minimizing the use of environmentally harmful insecticide sprays. Bt crops, which have a gene from the bacterium B. thuringiensis, have reduced insecticide use more than 20 percent. But concerns over potential harm to "non-target" organisms like monarch butterflies has added to the uncertainty surrounding Bt crops.
  • Disease resistance: GM techniques can protect crops from damaging viruses. The papaya industry in Hawaii, once devastated by the ringspot virus, was brought back from the brink of failure by the introduction of a virus-resistant, high-yielding GM variety. Today, around 80 percent of all papaya agriculture in Hawaii uses the GM variety, which has had no reported adverse health effects in humans.

    Indeed, many potential applications of GM crops have not been explored because of lingering concerns about safety. Other GM crops have been developed by international non-governmental research organizations and university research centers, but are still experimental or have yet to be widely commercialized. Crops have been developed to provide:

  • Drought resistance: Marginal ecosystems like those of sub-Saharan Africa are already being affected by climate change: increased droughts and water scarcity threaten the agricultural output that supports millions of people. Efforts to engineer hardier, drought-resistant strains of corn have produced 25 to 30 percent higher yields for farmers in several arid and semi-arid African nations, which may help reduce food shortages and alleviate famines.
  • Fortified food: Crop strains can be genetically modified to produce certain vitamins that are important to human nutrition. For example, a strain of rice—now known as "golden rice"—was modified to produce beta carotene, which the body converts into vitamin A. Fortified rice could help to alleviate malnutrition and vitamin deficiency in regions where rice is an important staple.
  • High-energy biofuels: While research is still at a basic stage, genetic modification may allow scientists to produce high-energy crops for use in biofuels like ethanol. Rather than using food crops like corn or sugarcane for ethanol (which can threaten food security), scientists may be able to modify strains of switchgrass and other perennials to have higher levels of cellulose for conversion to ethanol (Kintisch, 2008).
    Potential Risks of GM Agriculture

    While GM crop area continues to expand, controversy surrounding the technology's potential health and environmental risks has polarized the issue. Major concerns include, but are not limited to:

  • Toxicity: There is currently no evidence for toxicity in humans, although widespread epidemiological surveys have not been performed. There are greater concerns that GM crops could be toxic to wildlife, especially those varieties engineered for pest resistance. In 1999, research suggested that a specific variety of Bt corn was toxic to monarch butterflies. Subsequent studies by the U.S. Department of Agriculture concluded that the overall threat is low, but the example still highlights the high level of uncertainty surrounding the issue.
  • Allergenicity: Some GM opponents fear that genetically engineered foods are more likely to cause allergic reactions than are conventional foods. Although no allergic effects have been documented among GM foods currently on the market, protocols to test GM foods for allergenicity have been evaluated by the UN Food and Agriculture Organization and the World Health Organization.
  • Gene transfer to humans: If genes from GM foods, particularly the genes for antibiotic resistance used to create many GM organisms, transfer into humans during digestion, human health could be adversely affected. Although scientists deem the probability of transfer to be low, new technologies have been developed that avoid the use of antibiotic-resistance genes.
  • Development of "super-pests": Hybridization of GM crops with nearby weeds could transfer herbicide resistance or other beneficial traits to weeds. In addition, there is a proven threat that weeds or insects could develop resistance to certain pesticides through evolution. Although this phenomenon can and has affected both conventional and GM crop varieties, the evolutionary pressure to develop resistance is considered stronger when it comes to GM crops due to the greater reliance on a single gene and/or herbicide.
  • Shift to monoculture: While several studies have shown that GM crops do not significantly lower biodiversity, some GM opponents worry that they may to lead to monoculture: the planting of crop varieties. Already today, two-thirds of agricultural production is based on only three domesticated crop species: rice, wheat, and corn (Naylor and Manning 2005). Conventionally, farmers rotate their crops seasonally to control certain insects. The use of insecticide-producing GM crops may reduce this practice and could potentially increase monoculture, which may threaten food security in the long term.

    Dealing with Uncertainty

    The current debate surrounding GM agriculture is defined by uncertainty. Although both laboratory and field studies have generally failed to identify definite and substantial risks to human health or the environment, existing evidence is insufficient to rule them out. National governments and international organizations have responded with strict regulatory frameworks to control the testing, production and marketing of GM agriculture on a crop-by-crop basis. While regulations surrounding GM agriculture far exceed those controlling their conventional counterparts, gaps remain. Some organizations, most notably Greenpeace, continue to advocate for an outright global ban of GM crops.

    GM Crops for the Developing World

    The scientific body of knowledge surrounding GM agriculture is still inconclusive, but the future of GM crops will likely be decided more by political and regulatory realities than by any scientific consensus. Faced with uncertainty about genetic modification, and often pressured by its many vocal opponents, many governments now highly regulate the use of GM crops. These regulations are often so complicated that only large agrochemical corporations have the resources to successfully navigate them and gain approval for GM crops.

    Such regulations have often delayed or blocked the approval of GM crops that could provide humanitarian benefits to the developing world (see box). Given the significant upfront costs for research and development of new GM crops, and faced with an inhospitable regulatory climate, agrochemical corporations have few economic incentives to develop GM crops with humanitarian applications in mind. Currently, only two GM crops—Bt cotton and canola—are used in the developing world, mainly in China and India (Lavelle and Garber, 2008).

    Many major agricultural research programs now almost completely avoid using or developing GM crops because of the surrounding controversy. Conventional crops do have limitations, though, and in many cases GM crops can be more highly fortified and thus more nutritional. The Bill and Melinda Gates Foundation recently committed more than $300 million to increase agricultural yields by replenishing depleted soils and by introducing fortified GM foods in areas of high child malnutrition, a move which met with some criticism.

    The Future of GM Agriculture

    Today, anti-GM protests are prevalent and regulatory barriers to extensive GM use remain very high. GM bans in the European Union and Japan will keep demand for conventionally grown foods strong. In the future, though, increasing economic competition between GM and non-GM food exporters—and concern over soaring world food prices—may supersede such dissent. China, with its rapidly growing economy and burgeoning population, has heavily invested in agricultural biotechnology and now accounts for more than half of all world expenditures on GM crops, entirely financed by the Chinese government. In the future, increased use of GM agriculture in China and increased funding for high-quality scientific research may eliminate some uncertainty. Until then, a precautionary, case-by-case examination of the potential benefits and risks of each GM crop will be the most practical way forward.

    More Information on Social and Economic Policy
    More Information on Genetically Modified Organisms
    More Information on Environmental Degradation and Hunger
    More General Analysis on World Hunger
    More General Analysis on the Environment
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