All you need to know about Wool | Is it really sustainable?
What is Wool?
Wool is the textile fiber obtained from sheep and other animals which includes variants like cashmere, alpaca, etc. While most people associate the word “wool” with sheep, there are, in fact, a variety of distinct types of wool that producers derive from animals other than sheep.
The most famous and common type of wool is the Merino which is from Australia. Cashmere wool is derived from Pashmina goats found in Kashmir region in India and is one of the most luxurious and expensive kinds of wool. Other animals from whom wool is derived are alpaca, llama, angora rabbit, vicuna, camel.
The production of wool begins with the shearing of wool-bearing animals. The shorn wool then gets spun into a yarn and then gets converted into fabric.
Properties of Wool
Wool has a high Heat retention ability and hence is preferred as winterwear.
Wool is highly flame-resistant. It doesn’t spread flame, and instead, it chars and self-extinguishes.
Therefore, this type of textile is highly useful in applications in which the reduction of flammability is desired.
Wool is durable and has moderate breathability. It also has good water absorbency & moisture wicking abilities.
Wool is highly prone to bubbling and pilling
Where is Wool Produced?
Australia is the wool capital of the world due to the expanse of grazing land available and is responsible for 25% of total production. China, USA and New Zealand contributes to 18%,17% & 11% of Wool. 
Where is Wool used?
Wool is used in Formal Suits, trousers, jackets, sweaters, hats. It also has industrial applications because of its flame-retardant qualities. Wool is usually specified for garments for firefighters, soldiers, and others in occupations where they are exposed to the likelihood of fire. Wool carpets are specified for high safety environments, such as trains and aircraft.
Wool is a natural textile and hence is bio-degradable. Wool uses 18% less energy than polyester and nearly 70% less water than cotton to produce 100 sweaters. 
But the increasing demand for wool, specifically cashmere has some unimaginable environmental impact. The goats that are bred for cashmere destroy the plants they eat, by pulling them up by the roots rather than grazing the tops. This is causing the grasslands in China & Mongolia to disappear leading to air pollution & starvation of goats. As of 2016, the degradation of 65% of the grasslands in the area has been linked to a four-degree Fahrenheit increase in the temperature of Mongolia, three degrees higher than temperatures in other areas of the world. 
There are also concerns about inhuman handling of animals during shearing of wool.
Wool is an amazing fabric due to its thermal insulating properties. But increasing demand for wool can lead to unsustainable methods of production.
Therefore, everything boils down to the fact that we as consumers need to consume sustainably.