Cotton T-Shirt (Conventional)

Material Composition Assumptions

The default reference garment is a conventional cotton t-shirt weighing approximately 200 g, composed of:

• Cotton fiber: 100% conventional (non-organic) cotton, medium-staple upland variety — approximately 200 g finished weight (raw cotton input ~250 g accounting for processing losses)
• Dyes and chemicals: Reactive dye system with standard fixation agents, softeners, and finishing chemicals — approximately 5-10 g chemical input per garment
• Thread and trim: Cotton or polyester sewing thread, woven care label, printed hang tag — approximately 3-5 g
• Packaging: Polybag, cardboard insert, shipping carton (allocated per unit) — approximately 20 g

Cotton cultivation is assumed to be irrigated conventional farming with synthetic nitrogen fertilizer application. Nitrogen fertilizer is the primary driver of field-level emissions through direct and indirect N2O releases, which have a global warming potential approximately 265 times that of CO2.

Manufacturing Geography

The default manufacturing region is a blended South and East Asia scenario: cotton is grown in India, the USA, or West Africa, ginned and spun locally or in India/Pakistan, with fabric knitting, dyeing, and garment assembly in Bangladesh, India, or China.

• Grid intensity (India): 708 gCO2e/kWh (Ember Global Electricity Review 2025). India is used as the conservative default because it is a major hub for spinning, dyeing, and garment assembly with a coal-heavy electricity grid.
• Grid intensity (China): 565 gCO2e/kWh (IEA Emissions Factors 2024). China is a major alternative manufacturing location.
• Grid intensity (Bangladesh): Estimated ~550-600 gCO2e/kWh. Bangladesh is the world’s second-largest garment exporter but has limited published grid data.
• Rationale: Dyeing and finishing are the most electricity- and thermal-energy-intensive steps in cotton garment production. The wet processing stage (dyeing, washing, finishing) accounts for more than half of factory-level energy use, primarily through steam generation for heating water and subsequent drying.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
India (default)	~708 gCO2e/kWh	10.0 kgCO2e	Baseline
China	~565 gCO2e/kWh	9.4 kgCO2e	-6%
Bangladesh	~580 gCO2e/kWh	9.5 kgCO2e	-5%
EU (Portugal, Turkey)	~300 gCO2e/kWh	8.2 kgCO2e	-18%
USA	~390 gCO2e/kWh	8.6 kgCO2e	-14%

Note: Scope 2 (factory electricity and thermal energy) represents approximately 19% of the total footprint. Grid intensity variation has a moderate effect because Scope 3 upstream emissions (cotton farming, yarn spinning at supplier sites, chemical production) dominate the total score. Regional variation in agricultural practices (irrigation vs. rainfed, fertilizer intensity) can also shift Scope 3 emissions significantly.

Provenance Override Guidance

A supplier or brand may override the default CCI score by submitting:

1. Environmental Product Declaration (EPD) or Product Carbon Footprint (PCF) certified by an accredited third party per ISO 14067, PAS 2050, or the EU Product Environmental Footprint (PEF) method.
2. Cotton sourcing data specifying origin country, farming system (conventional, Better Cotton Initiative, organic), and whether irrigated or rainfed. Organic cotton from rainfed systems can reduce the cultivation hotspot by 30-50%.
3. Mill-level energy data for spinning, knitting/weaving, and dyeing facilities, including fuel mix (natural gas vs. coal for steam generation) and any renewable energy procurement.
4. Chemical and dye process data specifying dye class (reactive, vat, pigment), liquor ratio, and number of wash cycles. Low-liquor-ratio dyeing equipment can reduce wet processing energy by 30-40%.
5. Transport mode and distance data for finished goods distribution to point of sale.

Brands participating in the Sustainable Apparel Coalition (SAC) Higg Index and providing Higg FEM (Facility Environmental Module) verified data qualify for provenance override consideration.

Methodology Notes

• CCI score of 10 kgCO2e represents a conservative estimate aligned with peer-reviewed LCA literature. Li et al. (2016) report 8.77 kgCO2e for a Chinese cotton shirt; other studies report ranges of 6.5-15 kgCO2e depending on system boundaries and manufacturing location. The score of 10 kgCO2e accounts for typical Asian manufacturing with coal-intensive grids.
• Scope breakdown: Scope 3 dominates at 78% (7.8 kgCO2e), consistent with industry consensus that upstream raw material production, yarn spinning at supplier facilities, and chemical/dye manufacturing account for the majority of textile lifecycle emissions. Scope 2 (factory electricity and thermal energy for dyeing/finishing) is 19% (1.9 kgCO2e). Scope 1 (direct emissions from on-site boilers burning natural gas or coal for steam) is 3% (0.3 kgCO2e).
• Functional unit: One cotton t-shirt (~200 g), cradle-to-gate, including raw material cultivation, ginning, spinning, knitting, dyeing, finishing, cutting, sewing, and packaging. The gate is the finished packaged garment ready for distribution.
• Use-phase emissions (laundering over garment lifetime) are excluded from the CCI score. Laundering can add 3-8 kgCO2e over a garment’s useful life depending on wash frequency, water temperature, and dryer use.
• End-of-life: No credit or debit is included for end-of-life disposal or recycling. Approximately 85% of textiles end up in landfill or incineration globally.
• Data gaps: Cotton cultivation emissions vary significantly by country and farming system. The estimate uses a global weighted average of approximately 1.9 kgCO2e per kg of cotton fiber. Country-specific cultivation data would improve accuracy. Dyeing emissions also vary widely depending on dye type, equipment age, and factory energy source.