The number of political jurisdictions introducing climate change acts (CCAs) has grown in recent years. As framework legislation, CCAs seek to exert anchoring effects on climate policy development by establishing general goals, principles and obligations that subsequent policies to reduce emissions must uphold. Despite expansive research on the negotiation of CCAs, limited analysis exists of factors shaping their anchoring effect or how tensions aligning other climate policies with CCA requirements are managed. This article addresses this by utilizing Kingdon’s multiple streams framework to analyze the negotiation of the Irish Climate Action and Low Carbon Development (Amendment) Act 2021, a CCA with contentious provisions for sectoral emissions ceilings. It examines how political agreement was secured on the need for stronger climate action (problem stream), the concept of the Act (policy stream), and individual provisions (political stream). The analysis nevertheless indicates that different interpretations of ‘the problem’ emerged in discussions on the impacts of sector emissions ceilings and carbon taxation. Consensus in the political stream equally proved challenging where representatives used the Act’s provisions to question other parties’ commitments to climate action, just transition and procedural fairness. The article highlights two broader considerations for the anchoring effect of CCAs: the importance of maintaining a consistent focus on climate change to prevent problems with policies to address climate change from dominating CCA debates; and whether to restrict CCAs to general principles that diminish their anchoring effect compared with incorporating detailed obligations that may increase political tensions over the CCA and future policies.