In June 1992, the United States signed, and later ratified in October, the United Nations Framework Convention on Climate Change (UNFCCC). Pursuant to the national communication reporting requirements under Articles 4.2 and 12 of the Convention and to guidelines later adopted by the UNFCCC Conference of the Parties (COP), the United States submitted the first U.S. Climate Action Report (USCAR) to the UNFCCC Secretariat in 1994, the second in 1997, and the third in 2002. 

The draft of the fourth report was available on this site from May 4 through June 1, 2007 to allow the public to comment on the draft text of the national communication before the final document was completed. The final report was submitted July 27, 2007.  Copies of the comments are available upon request, and the report is available through the links below.

The Fourth United States Climate Action Report (CAR)
The fourth CAR provides an update on key activities conducted by the U.S. since the third CAR, an inventory of U.S. greenhouse gas emissions and sinks, an estimate of the effects of mitigation measures and policies on future emissions levels, and a description of U.S. leadership and involvement in international programs, including associated contributions and funding efforts. In addition, the text discusses U.S. national circumstances that affect U.S. vulnerability and responses to climate change. Finally, the CAR presents information on the U.S. Climate Change Science Program, the U.S. Climate Change Technology Program, our efforts in systematic observations, including the U.S. Integrated Earth Observation System, and our education, training and outreach efforts. The report takes into account activities up to and including 2006.

If you have any questions regarding the document or require any additional assistance, please contact Mr. Drew Nelson, Office of Global Change, U.S. Department of State, at (202)736-7444.

The Final Report is available as a series of PDF files linked below. The HTML version will be posted as soon as it is available. The draft of the report is also available.

Table of Contents of the Fourth U.S. CAR:

1. Introduction and Overview  [ PDF version   ]
2. National Circumstances  [ PDF version   ]
3. Greenhouse Gas Inventory  [ PDF version   ]
4. Policies and Measures  [ PDF version   ]
5. Projected Greenhouse Gas Emissions  [ PDF version   ]
6. Impacts and Adaptation  [ PDF version   ]
7. Financial Resources and Transfer of Technology  [ PDF version   ]
8. Research and Systematic Observation  [ PDF version   ]
9. Education, Training, and Outreach  [ PDF version   ]
Appendices