For better or for worse humans lack the fur and feathers that most animals have to maintain body temperature and buffer themselves from harsh weather.
While arguably not 100% necessary, clothing is has been considered a basic human need in many cultures for millennia, and is almost unavoidably necessary for warmth in cool climates. Textiles and clothing are extremely useful for a lot of other things including privacy and cleanliness.
The modern clothing industry is among the most ecologically and socially harmful, responsible for an estimated 20% of industrial water pollution as well as significant CO2 emissions.
Areas of Concern
Agricultural Standards
While the awareness and production of organic food has grown dramatically in the last decade, organic standards in textile farming are lagging with less the 1% of cotton grown organically and much non-organic cotton being grown from GMO seed with heavy use of pesticides.
While they are not easy to find and tend to seem expensive, certified organic alternatives can be found for all basic clothing needs.
Water Use
Cotton, the most commonly non-synthetic fiber used in clothing, is very water intensive to grow. It takes an estimated 2,770 liters of water to grow enough cotton for a single T-shirt (The equivalent of a 2 and 1/2 supply of drinking water for one person).
Dyes
Most textile fibers are dyed as part of the process of being turned into garments and many textile dyes used are toxic.
In many cases fibers are only dyed as a mater of preference and the issues associated with dyeing can be avoided entirely by simply choosing un-dyed fabrics. There are also many natural and non-toxic dyes available.
Labor Ethics
The textile industry has long been notorious for sweatshop labor with dangerous and inhuman working conditions.
If you consider how much time it would take you to make the shirt you're wearing and compare that to the amount of money you payed for it — taking into account the cost of materials, transpiration, and retail markup — you can get an idea of how fairly the person who made your clothing was compensated for their work.
Choose locally made and/or certified fair trade clothing to avoid participating in the exploitation of textile craftspeople.