In mitigating the adverse impact of global climate change, the role of binding international norms and effective national legal response addressing climate change is highly indispensable. As the impact of climate change transcends national borders, the development of international law took precedence albeit the specific challenges faced in seeking uniform undertaking of binding obligations among sovereign states. However, the development of international normative order governing climate change has only been gradual, and it continues to evolve. Consequently, national responses to climate change have been quite fragmented, making it difficult to assess how international climate change efforts are effectively reflected in a domestic context. The present paper, with an objective to investigate the scope and limitations of national implementation of international climate change mitigation norms, reviews the evolution and transformation of specific legal standards addressing climate change in distinct legal regimes. The paper critically examines the key international legal instruments on climate change and identifies the fundamental legal obligations emerging from those instruments to determine whether they have the potential to mandate sufficient national response measures. The paper reviews some of the key domestic laws and regulations aiming to mitigate the effects of climate change in two specific jurisdictions in the Pacific, namely Australia and New Zealand, to examine whether the relevant domestic regimes are progressive and responsive to international norms. The concluding part of the paper underlines the important findings regarding the international normative development and the transforming role of national legislative response and emphasizes the importance of national judicial activism in interpreting and enforcing the normative standards to ensure that climate justice is upheld in every possible opportunity.