The Kyoto Protocol (KP) is an international agreement under the UN Framework Convention on Climate Change that imposes binding limits on emissions of greenhouse gases for countries that have ratified the protocol. Because there are provisions in the KP that acknowledge benefits from terrestrial carbon sequestration, scientists in a variety of fields are engaged in applying their expertise to estimate quantities of carbon that are stored in forest and agricultural ecosystems. Periodically, meetings of groups of these scientists from around the globe are convened by the Intergovernmental Panel on Climate Change (IPCC) to develop consensus documents to establish a scientific basis for policy surrounding the KP. In the years since the KP was signed, the sequestration provisions of the protocol have been debated widely in scientific, policy, and public arenas. Issues range from economic impacts of sequestration efforts, to equity among developed and developing nations, to concerns about the certainty with which we can estimate carbon storage, to the advantages and disadvantages of substituting sequestration efforts for emissions reductions. Thus, the KP offers a case study of an environmental policy issue that has drawn widespread public attention in the US, scientific disagreement, and international contention. This presentation will discuss some observations by a participant in IPCC reports on forest carbon sequestration. The IPCC report development process will be described, as well as perspectives on the communication of science to policymakers and the public.