Textile fibre production has more than doubled over the past 30 years, leading to increased demands for both natural and fossil resources. Consumption of these resources must be controlled in order to reduce our environmental impact. However, it is important that novel means of production and consumption are economically viable and do not compromise human health and welfare.

This project aims to evaluate the market potential, environmental impact, and social sustainability of established, niche, and emerging textile fibres to determine the business case for clothing fibres in light of their sustainability impacts. It will also identify key knowledge gaps and opportunities for further research. This information provides one part of the evidence base for the Sustainable Clothing Roadmap coordinated by Defra.

The project involved a literature review complemented by the expert advice and technical knowledge of a stakeholder group. It examined both existing fibres with an established market share and emerging fibres that have technical properties suitable for clothing fibre production.

The fibres of interest were divided into three major groups: natural, regenerated (derived from natural polymers but requiring treatment and processing), and synthetic. Regenerated and synthetic fibres are commonly grouped as ―man-made fibres. For the purposes of the assessment of environmental impacts, textile fibre supply chains were divided into four processes from cradle to gate: raw material production, fibre preparation, fabric production, and dyeing and finishing. Literature and other sources of information were collated to identify the environmental impacts of each
fibre supply chain, from raw material production to factory gate for the above fibres. Data on energy use (indirect and direct) and water use for each phase of the chain was collated where available. Information on other impacts (greenhouse gas emissions, waste water emissions) was much more limited. Other impacts, such as land use demands for non-synthetic fibres, were calculated from the available data.

The environmental impacts of fibres during use and at end of life were also considered. However, Defra has commissioned separate evidence projects specifically focusing on these topics:
 Public Understanding of Sustainable Clothing (EV0405)
 Reducing the Environmental Impact of Clothes Cleaning (EV0419)
 Maximising Reuse and Recycling of UK Clothing and Textiles (EV0421)
This study draws on evidence from these reports where appropriate.

Taking land use impacts also into consideration (i.e. fibre productivity/ha) for fibres derived from natural resources adds a further dimension in terms of impacts on net GHG emissions per unit area of fibre crop (see Figure 43).

There is increasing pressure on demand for land and concerns that development of renewables from plant-derived biomass could affect food production, pushing up food costs and/or bring more land into agricultural production, resulting in a loss of biodiversity and other environmental impacts. Removal of biomass combined with the drainage, aeration, and disturbance of soils can lead to reduction in soil quality and increased soil respiration, resulting in a net increase in carbon dioxide emissions (Schlesinger 1997). Both impacts are particularly severe during deforestation due to the large above- and below-ground biomass stocks (Bradley et al. 2005).

In the absence of swapping/substitution of fibre crop areas, unless yields can be significantly increased, then raising the demand for natural fibres will increase the land requirement.