The ocean is the subject of the Law of the Sea Convention (LOSC), but it also plays a critical role in mediating climate – and climate change. As a result, to understand how LOSC can legally support the UN Climate Regime – the overall goal of this book – one must first understand the roles that the ocean plays in climate change, particularly with respect to the Climate Regime’s two foci, climate change mitigation and climate change adaptation. As Chapter 2 described, anthropogenic climate change is the result of humans burning fossil fuels since the Industrial Revolution, resulting in increased concentrations of greenhouse gases (GHGs) in the atmosphere that are accelerating the planet’s heat retention. The Intergovernmental Panel on Climate Change (IPCC) reported in 2014 that the planet has been warming since at least 1850, and the last thirty years are likely the hottest thirty-year period in the Northern Hemisphere in a millennium or more.