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 15 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.
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.
Globally, 35 million hectares of cotton are under cultivation.1 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 India, half of the pesticides used in all of agriculture are put toward cotton.2
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.4
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.5 In addition, synthetic fertilizers contribute an important quantity of greenhouse gases during their production and use.
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. A large amount of India’s cotton production is irrigated with groundwater, so you can imagine the damaging ramifications.6
Perhaps the most dramatic overuse of irrigation water is visible in Uzbekistan and Turkmenistan, where the Aral Sea declined in surface area by 80%.8 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 people who live downwind through an increase in miscarriages and malformations.9
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.11