USFS has an extensive ongoing R&D program regarding climate change. The program provides long term research, scientific knowledge, expertise, regional resources and tools that can be used to manage, restore, and conserve forests and rangelands.
An arm of the Energy Dept.'s Oak Ridge National Laboratory in Tennessee, the CDIAC focuses on research and data collection about carbon dioxide and the Earth's carbon cycle. It also tracks other greenhouse gases through its World Data Center for Atmospheric Trace Gases.
This research component of NOAA conducts all kinds of basic monitoring programs to compile long-term series of measurements and observations of the conditions that may be involved in climate change. The CMDL has now been merged into the Global Monitoring Division of the Earth System Research Laboratory.
This is the repository ("world's largest") of much of the raw data about the U.S. and planetary temperature record and other climate data. It is in Asheville, North Carolina.
Another pioneering climate lab that specializes in computer modeling of climate. No longer headed by the now-retired Dr. Jerry D. Mahlman, it is keeping a lower public profile these days. It is near Princeton University.
One of the largest, oldest, and best-respected federal labs working on climate, GISS is headed by Dr. James Hansen. It is in New York City.
US Climate Change Science Program (Interagency)
The coordinating point for all federal agencies working on climate science, the CCSP reports to the White House Council on Environmental Quality and Office of Science and Technology Policy via NOAA and the Commerce Department.
The IPCC is the umbrella organization that articulates not only the consensus among climate scientists, but also the breadth of opinion among them. It assembles and synthesizes the work of some 2,000 scientists in scores of disciplines from about 150 countries. Wikipedia. Press Contact.
This 20-page text distributed free in pdf format is by Mike MacCracken, former head of the U.S. Global Change Research Program.