As global sustainability regulations intensify, corporations face growing pressure to incorporate environmental, social, and governance (ESG) considerations into tax strategy, financial reporting, and long-term value assessment. Traditional effective tax rate (ETR) calculations focus solely on statutory obligations and recognized tax exposures, offering limited insight into how ESG-driven policies such as carbon pricing, pollution levies, green tax incentives, and supply-chain compliance costs influence a firm's real fiscal position. With many jurisdictions adopting carbon taxes, emissions-trading schemes, border-adjustment mechanisms, and ESG-linked fiscal incentives, companies require a structured tax-accounting framework that reflects sustainability impacts in measurable, financially comparable terms. This paper proposes an ESG-adjusted tax accounting model that integrates carbon pricing liabilities, decarbonization incentives, environmental remediation requirements, labor and governance-related compliance costs, and sustainability-linked tax credits into a unified effective tax rate calculation. The framework outlines clear methodologies for quantifying ESG-related tax exposures using carbon-intensity baselines, internal carbon-pricing models, Scope 1-3 emissions factors, and multi-jurisdictional tax-policy mapping. It further introduces reporting tools that translate these ESG-tax interactions into decision-useful financial insights, enabling firms to evaluate trade-offs between emissions-reduction investments, operational restructuring, and long-term tax-efficiency optimization. By aligning tax accounting with sustainability outcomes, the framework improves transparency for investors, enhances regulatory readiness, and allows corporations to anticipate fiscal impacts under evolving climate-policy regimes. Ultimately, ESG-adjusted ETR reporting supports more strategic capital allocation, strengthens risk management, and positions firms to navigate the future convergence of tax regulation, carbon markets, and global ESG accountability standards.