Genetically Modified Plants and the Environment

1. Fewer pesticides

The cultivation of herbicide-resistant and of pest- and disease-resistant plants is more economical for the farmer, and also environmentally beneficial. The cultivation of such crop plants may make a major contribution towards the maintenance of the quality of our soils and water resources.
There are already empirical data available from the United States concerning the cultivation of such crops.

Relatd examples:

• Corn-borer-resistant maize from the Novartis company

• Herbicide-tolerant soybeans from the AgrEvo and Monsanto companies

• Herbicide-tolerant oilseed rape from the AgrEvo and Monsanto companies

• Pest-resistant cotton (Bollgard® cotton) from the Monsanto company:

60% of American cotton farmers who cultivated Bollgard® cotton in 1996 did not use any insecticides to combat pests, while the remaining 40% used such agents only once. This is in contrast to between four to six applications of such insecticides in conventional cotton cultivation. In 1997, approximately 16% (1998: 20%) of the total American cotton-cultivation acreage was under cultivation with Bollgard® cotton. The increase in the yield in 1997 was 14%, the financial benefit for the farmers about 133 US dollars per hectare.

2. Protecting the diversity of the species

Worldwide agricultural production will have to be increased enormously by the year 2020 if we are to produce enough food to cover the nutritional requirements of the estimated world population of 7.67 billion people by that time. In many places this raised demand for food is met by excessive grazing of grasslands and by clearance of forests to enlarge the area available for agricultural utilization. Such methods destroy the habitats of many plants and animal species for good.
Genetic modification can counteract these developments. Enhanced crop characteristics such as a raised nutritional value and resistance towards crop pests and diseases allow increased yields on the same cultivation area or the same harvest yield on a smaller cultivation area.
This could release acreage for other agricultural purposes or for the preservation or even creation of habitats to protect the species diversity.

3. Environmentally compatible production methods

A sustainable population and environmental policy also demands an ecological re-orientation in the research-and-development sector. Energy- and raw-material-intensive industrial production should be improved. Genetically modified enzymes can help to achieve these goals, since in contrast to classic chemistry they work at low temperatures and pressure and do not use up valuable fossil fuels such as mineral oil, instead consuming renewable raw materials such as sugar and starch.
A comparison of the ecological balance sheets of the production of enzymes in genetically modified and non-modified microorganisms illustrates the immense saving of resources and the reduction in the amounts of waste that are generated, effects that result from the employment of genetic modification methods (for example: the manufacture of a-glucosidase, an enzyme for the production of sugars, in genetically modified and conventional yeasts).

4. Waste prevention

One of the most pressing environmental problems in industrialised nations is that of the constantly growing mountain of waste. Bioplastics produced in genetically modified plants could assist in alleviating the burden on the environment of conventional plastics. Much in the same way as animals use fat as an energy store, certain bacteria use substances similar to plastics.
These can be isolated and processed into bioplastic. In contrast to plastics conventionally manufactured from mineral oil, bioplastics are produced from renewable resources such as vegetable fats, oils, or carbohydrates. They are completely biodegradable and can be used as a source of nutrients by a lot of naturally occurring microorganisms. Bioplastic is still relatively expensive however, since the yield is very small. Genetically modified bacteria or plants may in future be used for industrial-scale production. Bioplastics could contribute in medicine; particularly in surgery where body-compatible implants are called for, or in the packaging-materials industry. The use of compostible shampoo bottles, beverage cartons, baby diapers, and other packaging materials could constitute an enormous reduction in the environmental burden imposed by conventional plastics.
Since 2 or 3 years some banks have been offering credit cards made of biodegradable plastic.
The cards consist of "Biopol", a bioplastic manufactured by Monsanto using microorganisms. Biopol is obtained from renewable resources (e.g. sugar or vegetable fatty acids) and can be disposed of by composting, being 99.9% free of PVC (polyvinyl chloride).
Employing genetic-modification methods Monsanto has also developed plants (oilseed rape) that produce relatively small amounts of Biopol (5% of the total weight) in their cells. The ultimate aim is to develop plants that consist of up to 20% by weight of Biopol, thereby enabling various bioplastics to be produced for a wide variety of applications.

5. Alleviation of already existing environmental damage

Genetic modification can not only help prevent environmental damage from occurring in the first place, it can also be used to alleviate such damage that has already occurred, for example the use of microorganisms or plants that are capable of degrading or resisting deleterious substances.
The methods traditionally used to eliminate industrial pollution are limited: contaminated soils for example, are excavated and deposited at waste dumps or else incinerated in special facilities. In both cases the transport costs involved are high, and the humus - which is important for the fertility of the soil - is lost in the process. When the soils are deposited, the pollutants are not destroyed, they are merely removed from the public eye, and the threat is merely postponed. In built-up areas, it is often impossible or at least extremely difficult to remove contaminated materials.
Bio-remediation constitutes an efficient, ecologically compatible, and inexpensive alternative to traditional techniques. Ideally, these methods enable the pollutants to be degraded into inorganic compounds in situ in the soil or groundwater using naturally occurring microorganisms.
Aluminium-tolerant plants: Many soils worldwide are contaminated with aluminium, with the result that harvest yields are severely reduced. A Mexican research team has transferred the gene for an enzyme responsible for the development of citric acid to various plants, such as, papaya and tobacco. Compared with normal plants, these exhibit significantly better growth in aluminium-contaminated soils. While this should not detract from the importance of avoiding contamination of soils with aluminium in the first place, plants such as these could one day play a decisive role in solving problems where such contamination has already occurred.
In another development, American scientists at the University of Georgia have succeeded in cultivating mustard plants that have the ability to take up mercury and convert it into a chemical compound that is far less damaging to the environment. If the results of the laboratory experiments translate into practice, in future it might be possible to clean up mercury-contaminated soils by the cultivation of such plants instead of having to deposit these soils in special waste dumps.

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