This paper examines the empirical relationship between climate-conscious capital allocation and corporate sustainability outcomes in the context of the global net-zero transition. Drawing on panel data from over 2,400 publicly listed firms across 42 countries spanning 2010–2023, we analyse whether green bond issuances, ESG-linked financing structures, and sustainability-indexed equity ownership materially improve firms' carbon intensity, renewable energy investment, and scope 1–3 emissions trajectories. Using difference-in-differences estimation with entropy-balanced propensity score matching, we find robust evidence that green bond issuers reduce scope 1 emissions by 11.4% and scope 2 emissions by 14.7% relative to matched non-issuers within three years of first issuance. ESG-linked loan covenants accelerate capital expenditure on clean technologies by 23% and improve environmental disclosure quality by 18 percentage points. Sustainability-indexed institutional ownership is associated with a 9.2% reduction in carbon intensity and a statistically significant increase in renewable energy as a share of total energy consumption. Heterogeneity analyses reveal larger effects for firms in high-emitting sectors and those domiciled in jurisdictions with mandatory climate disclosure regimes. Our results are robust to alternative identification strategies and are not explained by sample selection or reporting incentives alone. The findings carry significant implications for policymakers designing green finance taxonomies, regulators advancing disclosure mandates, and institutional investors constructing climate-aligned portfolios.