Cotton is the world's most used natural fiber, representing over 80% of global natural fiber use. However, its cultivation involves considerable consumption of water, energy, fertilizers, and pesticides, which impact both the environment and human health. Additional impacts arise from consumer activities such as washing and ironing. This review analyzes twenty peer-reviewed studies on cotton life cycle assessments, selected from Scopus and Web of Science according to PRISMA guidelines and covering the period 2010–2022. Among the inclusion criteria, studies addressing the cultivation phase were considered, while the exclusion criteria involved conference papers, book chapters and partial life cycle assessments. These studies indicate that cotton production—from cultivation to the final product—has the greatest impact on water use, energy consumption, greenhouse gas emissions and toxicity. Organic cotton farming demonstrates lower environmental impacts per unit area compared to conventional farming, but it exhibits higher impacts when evaluated on a mass basis. This discrepancy arises from the typically lower yields of organic systems relative to their conventional counterparts, emphasizing how the choice of functional unit can significantly influence the results and the conclusions drawn. Industrial processes like dyeing and spinning generate substantial carbon emissions, while consumer use—particularly washing and drying—accounts for over 65% of total energy consumption. The review identifies key sustainability issues in cotton production—high demand for and use of water, energy, and chemicals— and suggests strategies to mitigate the impacts across its life cycle such as efficient irrigation, optimized fertilization, the adoption of organic or Bt cotton, a shift towards renewable energy sources, and recycling.
