The U.S. is on the threshold of major changes in how it conducts climate change science research. These changes are being driven by several imperatives. One driving force is the growing recognition of the role that societal and ecological processes play in climate change. Another is the need to better support stakeholders who require climate-related information for the development of mitigation policy and adaptation activities. Wide expectations that the new administration will give new impetus to U.S. climate change research, along with increased Congressional interest also play a role. Finally, a new consensus that climate change is progressing much more rapidly than projected just two years ago adds a sense of urgency to these topics. This paper presents a high level picture of this state of events and the key issues that have arisen. It is one in a series of papers looking at climate change issues. The purpose of this series of papers is to raise awareness of the full scope of climate-related concerns. By identifying the key issues, each paper identifies potential opportunities for strengthening the U.S. response to climate change.