<p>As the urgency of climate action intensifies, the role of higher education in promoting carbon reduction and sustainable development has attracted growing global attention. As one of the world’s largest carbon emitters and a representative emerging economy, China plays a crucial role in achieving global carbon neutrality through its emission reduction efforts. Against this backdrop, there is a pressing need for large-scale and rigorous empirical investigation to assess whether higher education can serve as a key driver of decarbonization, and to understand how it contributes to climate action and the broader sustainability agenda. Such inquiry is essential for generating causal evidence and informing effective policy decisions. Using provincial panel data from China from 2008 to 2021, this study conducts a comprehensive empirical analysis of the impact of higher education on regional carbon emissions, employing fixed effects models, instrumental variable techniques, and other econometric strategies. The findings reveal that: (1) Higher education significantly reduces carbon emissions, as confirmed by a series of robustness checks and endogeneity tests. (2) This effect is primarily mediated through the mechanisms of technological innovation, industrial structure upgrading, and improved energy efficiency, among which the transmission effect of the energy efficiency improvement mechanism is the strongest. (3) The carbon reduction impact follows a pattern of diminishing marginal returns and exhibits regional heterogeneity, with stronger effects in economically less advanced central and western regions. (4) Higher education moderates the inverted U-shaped relationship between economic development and carbon emissions (Environmental Kuznets Curve), enabling lower emissions at equivalent or higher levels of economic growth. This offers a novel analytical perspective on how higher education contributes to a dynamic balance between economic growth and environmental protection. (5) Higher education also generates positive spatial environmental effects by reducing carbon emissions in neighbouring regions through spatial spillovers, highlighting its significance as a public good with broad environmental benefits and its potential to contribute to climate governance beyond geographic boundaries. This study deepens theoretical understanding of higher education’s role in climate governance, strengthens its conceptual connections with environmental and climate justice, and contributes to the evolving discourse on the university’s “third mission”. The findings provide policy-relevant insights for enhancing the contribution of higher education to climate action and sustainable development in China and globally.</p>