COTTON
The Bad
Conventional growing of cotton results in degradation of the soil, increased use of fertilizers and pesticides because of this and contamination of surrounding land and water systems through this use.
Expansion into new areas causes destruction of habitats.
Some experts believe that cotton is the largest user of water among all agricultural commodities. The Aral Sea has dried up partly because of cotton plantations in its catchment.
A pair of cotton jeans weigh about 600g. Their production has a footprint of around 26kg CO2e per kilo. (That includes all the processes involved in the production of a pair of jeans.) This means that a single pair of jeans has a footprint of around 19kg.
Add to that 12kg CO2e for the washing and drying over their lifetime and another 1kg CO2e if they end up in landfill and that brings one pair of jeans having a footprint of up to 32kg CO2e.
You can bring this down by washing them less often and line drying but the footprint will still end up at over 20Kg CO2e.
The Good
WWF in partnership with IKEA began a project to promote better ways of growing cotton.
This was so successful that a multi-stakeholder organisation was formed called BETTER COTTON.
Farmers adopting this initiative are growing healthier cotton, reducing water use by 39%, pesticides by 47% and chemical fertilizers by 39%
and their yields increased by 11%.
Cotton is degradable (given the right conditions).
Look at WWF website www.worldwildlife.org and Mike Berners Lee’s book “How Bad Are Bananas?” for much more info on cotton.
WOOL
The Bad
Wool comes from sheep, which are ruminants. That means that they feed on plant material and burp Methane, another contributor to 
Global Warming.
Once the wool has been shorn from the sheep, it goes through a long process of sorting, scouring, carding and spinning before it can be used to produce textiles. This process involves the use of strong alkaline chemicals and chemical dyes.
The Good
The Guardian reports that scientists are working on a breed of sheep that emits less Methane.
Sheep thrive on land, which cannot be used for other agricultural processes. This gives income to the farmers, who care for them.
Wool is a terrific insulator and is lovely to wear (unless you have an allergy).
Wool is completely degradable (given the right conditions).
The meat of sheep comes from animals who have had a free ranging life, living on natural food.
