Scientists who believe that human activities are contributing significantly to climate change often express frustration with what they perceive to be an inadequate response by the international community to an imminent and substantial threat to human and natural systems. Such frustrations often reflect a lack of understanding of the complexities of our international system, which has no central authority and relies on the ability of more than 180 sovereign nations with extremely diverse cultures and interests to reach consensus on just what should be done. This paper will provide an overview of the international system and why it is so difficult to reach a global agreement to make significant reductions in greenhouse gas emissions and to help vulnerable human and natural communities to adapt to a changing climate. It will review major provisions of the United Nations Framework Convention on Climate Change (UNFCCC), such as common but differentiated responsibilities, the precautionary principle, and sustainable development. It also will discuss why the role of the Intergovernmental Panel on Climate Change (IPCC), the primary scientific review group in the climate policy debate, has been directed to be policy relevant but not policy prescriptive. The paper will describe the four building blocks of the Bali Roadmap, mitigation, adaptation, financing, and technology transfer, and will provide an update on negotiations from the United Nations Climate Change Conference to be held in December 2008 in Poznan, Poland.