This chapter aims to reveal some of the complexity of the problem while also shedding light on several major and recurring attributes of the problem. It summarizes some of the scientific findings on climate change and notes how climate science has been politicized. The chapter describes how governments have negotiated a regime of international agreements and institutions intended to address climate change collectively and individually. The politics of climate change have been tortuous and slow, particularly at the international level. The underlying scientific understanding of climate change, which feeds into national policy and international negotiations on climate change, was developed by scientists collaborating internationally. Climate change also presents potentially even more profound questions of global justice. Subsequent climate negotiations resulted in incremental steps toward action on climate change, in the process highlighting recurring differences among states about how best to achieve the objectives of both the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol.