In 1990, the Congress enacted the Global Change Research Act. This act, among other things, required the administration to (1) prepare and at least every 3 years revise and submit to the Congress a national global change research plan, including an estimate of federal funding for global change research activities to be conducted under the plan; (2) in each annual budget submission to the Congress, identify the items in each agency’s budget that are elements of the United States Global Change Research Program (USGCRP), an interagency long-term climate change science research program; and (3) report annually on climate change “expenditures required” for the USGCRP. In 1992, the United States signed and ratified the United Nations Framework Convention on Climate Change, which was intended to stabilize the buildup of greenhouse gases in the earth’s atmosphere, but did not impose binding limits on emissions. In response to the requirements of the 1990 act, the administration reported annually from 1990 through 2004 on funding for climate change science in reports titled Our Changing Planet. From 1990 through 2001, the reports presented detailed science funding data for the USGCRP. Federal climate change science programs were reorganized in 2001 and 2002. In 2001, the Climate Change Research Initiative (CCRI) was created to coordinate short-term climate change research focused on reducing uncertainty, and in 2002, CCSP was created to coordinate and integrate USGCRP and CCRI activities. CCSP is a collaborative interagency program designed to improve the government wide management of climate science and research. Since 2002, CCSP has been responsible for meeting the reporting requirement and has published the Our Changing Planet reports. The most recent report in this series was published in November 2005. The Climate Change Technology Program (CCTP) is a multiagency technology research and development coordinating structure similar to CCSP. Its overall goal is to attain, on a global scale and in partnership with other entities, a technological capability that can provide abundant, clean, secure, and affordable energy and related services needed to encourage and sustain economic growth, while achieving substantial reductions in emissions of greenhouse gases and mitigating the risks of potential climate change. In March 1998, OMB, in response to a congressional requirement for a detailed account of climate change expenditures and obligations, issued a brief report summarizing federal agency programs related to global climate change. OMB produced another climate change expenditures report in March 1999 and, in response to a request at a 1999 hearing, OMB provided climate change funding data for 1993 through 1998 for the hearing record. Each year since 1999, the Congress has included a provision in annual appropriations laws requiring OMB to report in detail all federal agency obligations and expenditures, domestic and international, for climate change programs and activities. As a result of these reporting requirements, OMB annually publishes the Federal Climate Change Expenditures Report to Congress, which presents federal climate change funding for the technology, science, and international assistance categories, and tax expenditures. The climate change activities and associated costs presented in OMB reports must be identified by line item as presented in the President’s budget appendix. OMB has interpreted this to mean that the data in the reports must be shown by budget account. For the last 3 years for which we reviewed data, the Congress had required that the administration produce reports for climate change expenditures and obligations for the current fiscal year within 45 days after the submission of the President’s budget request for the upcoming fiscal year. OMB’s most recent report was released in April 2006. OMB reports include a wide range of federal climate-related programs and activities. Some activities, like scientific research on global environmental change by USGCRP, are explicitly climate change programs, whereas others, such as many technology initiatives, are not solely for climate change purposes. For example, OMB reports included some programs that were started after the United States ratified the Framework Convention in 1992 and were specifically designed to encourage businesses and others to reduce their greenhouse gas emissions, for example, by installing more efficient lighting. OMB reports also included programs that were expanded or initiated in the wake of the 1973 oil embargo to support such activities as energy conservation (to use energy more efficiently), renewable energy (to substitute for fossil fuels), and fossil energy (to make more efficient use of fossil fuels), all of which can help to reduce greenhouse gas emissions, but were not initially developed as climate change programs. Federal climate change funding, as reported by OMB, increased from $2.35 billion in 1993 to $5.09 billion in 2004 (116 percent), or from $3.28 billion to $5.09 billion (55 percent) after adjusting for inflation. Funding also increased for technology, science, and international assistance between 1993 and 2004, as shown in table 1. However, changes in reporting methods have limited the comparability of funding data over time; therefore it is unclear whether funding increased as much as reported by OMB. OMB did not report estimates for existing climate-related tax expenditures during this period, although climate-related tax expenditures amounted to hundreds of millions of dollars in revenue forgone by the federal government in fiscal year 2004. OMB officials told us that changes in reporting methods were due to such reasons as the short amount of time available to prepare the report, the fact that the reporting requirement is not permanent law, but appears each year in their appropriations legislation, and changes in administration policy and priorities. As a result of our recommendations, however, OMB made changes in its report on climate change funding for fiscal year 2007, which was published in April 2006. For example, OMB more clearly labeled data throughout the report and added information on existing tax provisions that can contribute to reducing greenhouse gas emissions. From 1993 through 2004, technology funding increased as a share of total federal climate funding from 36 percent to 56 percent, as reported by OMB. Over this period, technology funding increased from $845 million to $2.87 billion (239 percent), or adjusted for inflation, from $1.18 billion to $2.87 billion (143 percent). For example, funding for energy conservation increased from $346 million to $868 million, and funding for renewable energy increased from $249 million to $352 million. Table 2 presents funding data for selected years for the seven largest accounts, which accounted for 92 percent of technology funding in 2004. We identified three ways that the data on technology funding presented in three of OMB’s recent reports may not be comparable to the data presented in previous reports. First, OMB added accounts that were not previously presented. For example, OMB reported that NASA had $152 million in funding for technology-related activities, which included research to reduce emissions associated with aircraft operations in 2003. OMB did not report this account in the technology category in 2002. In addition, OMB included and removed some accounts, without explanation, from reports in years other than 2003. For example, OMB reported combined funding of $195 million in 1999, and $200 million in 2000, for bio- based products and bio-energy at the Departments of Energy and of Agriculture. No funding for these accounts was reported from 1993 through 1998 or from 2001 through 2004. In each of these cases, OMB did not explain whether the new accounts reflected the creation of new programs, a decision to count an existing program for the first time, or a decision to re-classify funding from different categories as technology funding. According to OMB officials, these changes in report structure and content for technology funding, as well as similar changes in science and international assistance funding, were the result of time constraints and other factors. They told us that the short timeline required by the Congress for completing the report (within 45 days of submitting the upcoming year’s budget) limited OMB’s ability to analyze data submitted by agencies. They said that they must rely on funding estimates quickly developed by agencies in order to produce the report within the specified timeframe, and that the reports are often compilations of agency activities and programs, some of which may or may not have been presented separately in prior years. Moreover, these officials told us that the presentation of data has changed over time for a variety of reasons other than short time limits, including changes in administration priorities and policy, changes in congressional direction, changes to budget and account structures, and attempts to more accurately reflect the reporting requirement as specified in the annual appropriations language. The officials also stated that in each report they ensured consistency for the 3 years covered (prior year, current year, and budget year). Furthermore, OMB officials told us that the presentation of new accounts in the technology category, as well as the international assistance category, was due to the establishment of new programs and the inclusion of existing programs. They told us that the account-by-account display in the reports has been changed over time as the CCSP and the Climate Change Technology Program (CCTP), a multiagency technology research and development coordinating structure similar to the CCSP, have become better defined. Second, OMB reported that it expanded the definitions of some accounts to include more activities but did not specify how the definitions were changed. We found that over 50 percent of the increase in technology funding from 2002 to 2003 was due to increases in two existing DOE accounts: nuclear energy supply and science (fusion, sequestration, and hydrogen). OMB reported funding of $32 million in 2002 and $257 million in 2003, for the nuclear energy supply account and reported funding of $35 million in 2002, and $298 million in 2003, for the science (fusion, sequestration, and hydrogen) account. Although OMB stated in its May 2004 report that 2003 funding data included more activities within certain accounts, including the research and development of nuclear and fusion energy, the report was unclear about whether the funding increases for these two existing accounts were due to the addition of more programs to the accounts or increased funding for existing programs already counted in the accounts. Finally, if new programs were counted in these accounts, OMB did not specify what programs were added and why.