This section investigates the long term trajectory of carbon emissions in Turkey’s crude steel production between 1978 and 2024. The analysis distinguishes between oxygen-based and electric processes. Changes in production composition are examined in relation to carbon intensity within a nonlinear framework. Stationarity properties of the series are tested using ADF, KPSS, ZA, and KSS unit root tests. Nonlinearity is assessed with the BDS test. Long-run coefficients are estimated through the NARDL model. Causality patterns are examined using the Hatemi J asymmetric causality test. The findings indicate a long term and nonlinear association between production composition and carbon emissions in Turkey’s crude steel sector. Increases in both oxygen based and electric production are associated with higher emissions. The magnitude of the effect varies according to the direction of shocks. Results from the asymmetric causality analysis point to a stronger link between oxygen based production and carbon dynamics. The environmental impact of electric production is closely related to the carbon intensity of the energy mix.