Green criminology and climate justice scholarship recognise that government power has limited climate regulation at an international level. The resulting structural violence caused by systemic inequalities and power imbalances means that low-income communities, Indigenous groups, and people in the Global South are disproportionately impacted by increases in greenhouse gas emissions. This chapter uses a descriptive case study method to demonstrate that countries in the Global South, particularly Pacific Island Countries, are playing an innovation role in shaping international climate obligations. The Global North’s climate inaction, delaying tactics, and failure to accept climate liability are all actions that green criminologists would call criminal. These ‘crimes’ have pushed Global South States to utilise international law in innovative ways to hold Global North States accountable to their obligations. The first case study focuses on the development of new laws, specifically the development climate finance for Loss and Damage, and Fiji, Samoa, and Vanuatu’s push to amend the Rome Statute to recognise ecocide as an international crime. The second case study explores the Advisory Opinions on state responsibility and climate change delivered by the International Tribunal for the Law of the Sea and the International Court of Justice. This chapter argues that Pacific Island Nations are leading the response against the climate crimes of continuing extraction and emission, denial, and political omission through innovative diplomatic and legal strategies to make international law more horizontal and hold the Global North accountable to their obligations under international law.