The Environmental Costs of Cotton

Combines harvesting cotton
Combines harvesting cotton. Fernando Bueno/Getty Images

Whether we wear cotton shirts or sleep in cotton sheets, chances are that on any given day, we utilize cotton in some way. Yet few of us know how it is grown or its environmental impact.

Where Is Cotton Grown?

Cotton is a fiber grown on a plant of the Gossypium genus, which, once harvested, can be cleaned and spun into the fabric we know and love. Needing sunshine, abundant water, and relatively frost-free winters, cotton is grown in a surprising variety of locations with diverse climates, including Australia, Argentina, West Africa, and Uzbekistan. However, the largest producers of cotton are China, India, and the United States. Both Asian countries produce the highest quantities, mostly for their domestic markets, and the U.S. is the largest exporter of cotton with about 10 million bales each year.

In the United States, cotton production is mostly concentrated in an area called the Cotton Belt, stretching from the lower Mississippi River through an arc spanning the lowlands of Alabama, Georgia, South Carolina, and North Carolina. Irrigation allows additional acreage in the Texas Panhandle, southern Arizona, and California’s San Joaquin Valley.

Is Cotton Bad for the Environment?

Knowing where cotton comes from is only half the story. At a time when the general population is moving toward greener practices, the bigger question asks about the environmental cost of growing cotton.

Chemical Warfare

Globally, 35 million hectares of cotton are under cultivation. To control the numerous pests feeding on the cotton plant, farmers have long relied on the heavy application of insecticides, which leads to the pollution of surface and groundwater. In developing countries, half of the pesticides used in all of agriculture are put toward cotton.

Recent advancements in technology, including the ability to modify the cotton plant’s genetic material, have made cotton toxic to some of its common pests. Though this has reduced the use of insecticides, it hasn't eliminated the need. Farmworkers, particularly where the labor is less mechanized, continue to be exposed to harmful chemicals.

Competing weeds are another threat to cotton production. Generally, a combination of tilling practices and herbicides are used to knock back weeds. A large number of farmers have adopted genetically modified cotton seeds that include a gene protecting it from the herbicide glyphosate (the active ingredient in Monsanto’s Roundup). That way, the fields can be sprayed with the herbicide when the plant is young, easily eliminating competition from weeds. Naturally, glyphosate ends up in the environment, and our knowledge of its effects on soil health, aquatic life, and wildlife is far from complete.

Another issue is the emergence of glyphosate-resistant weeds. This is an especially important concern for those farmers interested in following no-till practices, which normally help preserve the soil structure and reduce erosion. If glyphosate resistance doesn't work for controlling weeds, soil-damaging tilling practices may need to resume.

Synthetic Fertilizers

Conventionally grown cotton requires the heavy use of synthetic fertilizers. Unfortunately, such concentrated application means that much of the fertilizers end up in waterways, creating one of the worst nutrient-pollution problems globally, upending aquatic communities and leading to dead zones starved of oxygen and devoid of aquatic life. In addition, synthetic fertilizers contribute an important quantity of greenhouse gases during their production and use.

Heavy Irrigation

In many regions, rainfall is insufficient to grow cotton. However, the deficit can be made up by irrigating the fields with water from wells or nearby rivers. Wherever it comes from, the water withdrawals can be so massive that they diminish river flows significantly and deplete groundwater. Two-thirds of India’s cotton production is irrigated with groundwater, so you can imagine the damaging ramifications.

In the United States, western cotton farmers rely on irrigation as well. Obviously, one could question the appropriateness of growing a non-food crop in arid portions of California and Arizona during the current multi-year drought. In the Texas Panhandle, cotton fields are irrigated by pumping water from the Ogallala Aquifer. Spanning eight states from South Dakota to Texas, this vast underground sea of ancient water is being drained for agriculture far faster than it can recharge. In northwest Texas, Ogallala groundwater levels have dropped over 8 feet between 2004 and 2014.

Perhaps the most dramatic overuse of irrigation water is visible in Uzbekistan and Turkmenistan, where the Aral Sea declined in surface area by 85%. Livelihoods, wildlife habitats, and fish populations have been decimated. To make matters worse the now-dry salt and pesticide residues are blown away from the former fields and lake bed, negatively impacting the health of the 4 million people who live downwind through an increase in miscarriages and malformations.

Another negative consequence of heavy irrigation is soil salination. When fields are repeatedly flooded with irrigation water, salt becomes concentrated near the surface. Plants can no longer grow on these soils and agriculture has to be abandoned. The former cotton fields of Uzbekistan have seen this issue on a large scale.

Are There Environmentally Friendly Alternatives for Cotton Growth?

To grow cotton in a more environmentally friendly way, the first step must be to reduce the use of dangerous pesticides. This can be achieved through different means. Integrated Pest Management (IPM), for example, is an established, effective method of fighting pests which results in a net reduction of pesticides used. According to the World Wildlife Fund, using IPM decreased pesticide use for some of India’s cotton farmers by 60–80%. Genetically modified cotton can also help reduce pesticide application, but with many caveats.

Growing cotton in a sustainable manner also means planting it where rainfall is sufficient, avoiding irrigation altogether. In areas with marginal irrigation needs, drip irrigation offers important water savings.

Finally, organic farming takes into consideration all aspects of cotton production, leading to reduced environmental impacts and better health outcomes for both farmworkers and the surrounding community. A well-recognized organic certification program helps consumers make smart choices and protects them from greenwashing. One such third-party certification organization is the Global Organic Textile Standards.

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