We have all become more aware of the environmental impact of our clothing choices. The fashion industry has seen a rise in "green," "eco" and "sustainable" clothing. This includes an increase in the use of natural fibres, such as wool, hemp, and cotton, as synthetic fabrics, like polyester, acrylic and nylon, have been vilified by some.
However, the push to go "natural" obscures a more complex picture.
Natural fibres in fashion garments are products of multiple transformation processes, most of which are reliant on intensive manufacturing as well as advanced chemical manipulation.
While they are presumed to biodegrade, the extent to which they do has been contested by a handful of studies. Natural fibres can be preserved over centuries [tandfonline.com] and even millennia [springer.com] in certain environments. Where fibres are found to degrade they may release chemicals, for example from dyes, into the environment [acs.org].
Perhaps the real threat to the environment is over-consumption.