This paper reconciles the debates on carbon return estimation by introducing the concept of equity duration. We demonstrate that emission level and emission intensity yield divergent results for green firms, driven by inherent data problems. Our findings reveal that equity duration effectively captures the multifaceted effects of carbon transition risks. Regardless of whether carbon transition risks are measured by emission level or emission intensity, brown firms earn lower returns than green firms when the equity duration is long. This relationship reverses for short-duration firms. Our analysis underscores the pivotal role of carbon transitions’ multifaceted effects on cash flow structures in understanding the pricing of carbon emissions.