Scientists have discovered that changes in the earth's climate are induced by the increasing concentrations of certain gases in the earth's atmosphere--some naturally occurring, others human-induced--that have the potential to significantly alter the planet's heat and radiation balance. These so-called "greenhouse gases" trap some of the sun's energy and prevent it from returning to space. The trapped energy warms the earth's climate, much like glass in a greenhouse. Over the past century, humans have contributed to the greenhouse effect, particularly by burning fossil fuels, which increased atmospheric carbon dioxide and other greenhouse gases. The effects of a warmer climate could have important consequences for human health and welfare by, among other things, altering weather patterns, changing crop yields, and leading to the flooding of coastal areas. According to the Department of Energy's Energy Information Administration (EIA), in 2001, the most recent year for which data are available, the United States and other developed nations accounted for just under half (47 percent) of the world's emissions of carbon dioxide--the most prevalent greenhouse gas. The other emissions came from economically developing nations, including China, India, and Mexico (40 percent), and from nations with economies in transition (13 percent) in Europe and the Former Soviet Union. EIA projects that, over the next 2 decades, carbon dioxide emissions from each of the three nation groups will increase; however, carbon dioxide emissions from developing nations will increase most dramatically, surpassing those of developed nations by 2015, as shown in figure 1. More specifically, figure 2 shows actual and projected carbon dioxide emissions for the seven nations in our study. Growth in emissions between 2001 and 2025 is projected to range from 29 million metric tons for the United Kingdom to 1,012 for China. The seven nations in our study also differ greatly in terms of their population and per capita income (an indicator of economic development). For example, population ranged from about 60 million in the United Kingdom to nearly 1.3 billion in China, and per capita income ranged from $2,540 in India to $36,300 in the United States. (See table 1.) Under the Framework Convention, the United States and the other parties generally agreed to implement policies and measures aimed at returning "individually or jointly to their 1990 levels these anthropogenic [human- caused] emissions" of greenhouse gases not covered by another treaty, the Montreal Protocol. The six primary gases covered by the Framework Convention are carbon dioxide, nitrous oxide, methane, and three synthetic gases--sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons. Emissions of these gases are generally not measured because doing so would be too costly; consequently, they must be estimated. In this regard, the IPCC, at the parties' request, developed detailed guidance on methodologies for nations to use when estimating their emissions and revised that guidance twice, most recently in 1999. Both developed and developing nations are required to follow this guidance--Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories--when preparing their inventories. In addition, in 2000, the IPCC published--also at the parties' request--its Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories, which contains information on prioritizing tasks to arrive at the best possible estimates using finite resources as well as advice on establishing quality assurance programs, among other things. The nations have been encouraged, but not required, to follow the good practice guidance. The parties to the Framework Convention also agreed to report periodically to the Secretariat on their levels of greenhouse gas emissions. For Annex I nations, those reports are extensive. Annually, each Annex I nation is required to submit inventory data--in a common reporting format the parties themselves agreed to--as well as a national inventory report that explains how the data in the common reporting format were derived. The common reporting format calls for data for each of the six emissions sectors--energy, industrial processes, solvent and other product use, agriculture, land-use change and forestry, and waste--as well as for the data on the major sources that contribute to emissions from each sector. The inventory data are to reflect a nation's most recent reporting year as well as all previous years back to the base year, which is 1990. For each year, the common reporting format calls for 42 tables containing over 8,100 items that are sector-specific numbers; data summarized across sectors; and other information, such as trends from the base year to the current reporting year, recalculations of prior years' data, and reasons certain emissions were not estimated. The parties require that data be submitted in the common reporting format to facilitate comparison across nations and to make it easier to review the data. Because an inventory contains data from the base year to the most recent reporting year, each year's submission is larger than the last. The 2003 reporting format called for approximately 98,000 items of inventory data and other information from 1990 through 2001. The national inventory report, the second component of the submission, should be detailed and complete enough to enable reviewers to understand and evaluate the inventory. The report should include, among other things, descriptions of the methods used to estimate the data, the rationale for selecting the methods used, and information about the complexity of methods and the resulting precision of the estimates; information on quality assurance procedures used; discussion of any recalculations affecting previously submitted inventory data; and information on improvements planned for future inventories. Each year, when Secretariat staff receive Annex I nations' submissions, they perform an initial check to determine whether the submissions are complete and then synthesize the information to facilitate comparison across nations. Teams of expert reviewers--comprising members chosen by the parties for their sector expertise as well as to achieve broad geographic representation--also use this synthesized information to identify issues requiring clarification during their reviews of individual submissions. From 2000 through 2002, the parties tested the usefulness of three methods of conducting expert reviews on selected submissions from Annex I nations. The first type of review, called a desk review, consists of about 10 experts spending about 4 weeks in their respective nations reviewing information on the same three nations' inventories. For this type of review, the experts communicate with each other and the nation being reviewed via the Internet and telephone. The second type of review, called a centralized review, involves about 10 experts spending about a week at the Secretariat's headquarters in Bonn, Germany, jointly reviewing between four and six nations' inventories. The third review type, called an in- country review, consists of a team of about 5 experts spending a week in the nation whose inventory is being reviewed, jointly examining the nation's inventory and supporting information. The Secretariat chose inventories of different levels of completeness to undergo desk and centralized reviews; only nations that volunteered for an in-country review received one. During the 3-year test period, the experts examined the data and supporting information the nations used to prepare the inventories via all three types of reviews. For example, the experts determined whether a nation calculated its emissions estimates using formulas from published data sources or formulas specified by the parties. The experts also verified the information provided in response to questions raised in previous reviews. Finally, the experts summarized the inventories' strengths and weaknesses; made recommendations for improvement, if warranted; and presented their findings in reports that were both published and posted on the Internet. For Annex I nations' submissions to be reviewed by the experts, the submissions must meet two criteria. Since 2000, the experts have reviewed only submissions that presented their data in the common reporting format, and, beginning with the 2003 submissions, the experts will review only submissions that include the national inventory report. According to the parties to the Framework Convention, the goal of the expert reviews is to identify areas in the inventories needing improvement; for this reason, the experts' reports do not rate the overall quality of the submissions, and the reports do not identify some findings as being more important than others. According to the Secretariat, since 1998, Annex I nations' submissions have steadily and substantially improved in their timeliness and completeness, and the expert review process has contributed to the improved quality of recent submissions. Non-Annex I nations' requirements for format and frequency of reporting differ from those for Annex I nations. Although all parties to the Framework Convention are to develop their inventories using the revised 1996 IPCC guidelines and submit the inventories to the Secretariat, non- Annex I nations' inventories are not stand-alone documents. Rather, a non- Annex I nation's inventory is a component of its national communication, which is a report it must submit to the Secretariat that discusses all of the steps the nation is taking or plans to take to implement the Framework Convention. In addition, non-Annex I nations are not required to use the common reporting format or to submit a national inventory report. Moreover, non-Annex I nations are not required to submit an inventory each year but may instead negotiate the frequency of their submissions. To date, most non-Annex I nations negotiated a deadline for only one inventory. To help the non-Annex I nations develop and report their inventories, the developed nations of Annex I provide financial assistance that is disbursed through the convention's financial mechanism, the Global Environment Facility. The facility, which funds various types of environmental projects in developing nations, disburses the funds, including those to assist non-Annex I nations with their emissions reporting, through implementing agencies, such as the United Nations Development Program. The implementing agencies, in turn, disburse the funds to the nations on a schedule and according to terms negotiated by the agency and each nation. The inventory reviews and the extent to which the results are reported also differ for Annex I and non-Annex I nations. Reviews of Annex I nations' submissions focus on compliance with reporting standards, and the results are made publicly available in considerable detail. In contrast, because non-Annex I nations are generally in the early stages of developing their inventories and have limited resources to do so, assessments of their submissions, and the resulting reports, focus largely on providing a forum for the non-Annex I nations to exchange information on common reporting problems and best practices. Consequently, while the Secretariat makes reports on the results of non-Annex I assessments publicly available, it does so in summary format and provides only a few nation-specific details in tables that accompany the aggregated reports. The most recent expert reviews of inventories submitted by the four developed nations found that the U.K. and U.S. inventories contained most of the required elements, but the German and Japanese inventories were missing certain critical elements. Experts reviewed inventories variously submitted from 2000 through 2002 by each of the four developed nations in our study. The inventories submitted by Japan and Germany in 2000 and 2001, respectively, each received a centralized review. Two U.K. inventories were reviewed: the one submitted in 2000 received an in-country review, and the one submitted in 2002 received a desk review. The inventory that the United States submitted in 2000 received both an in-country review and a desk review. Although the experts planned to conduct reviews of all Annex I nations' inventories submitted in 2003, no results were available at the time of our study. The reviews of the submissions of the United Kingdom and the United States found they were largely complete and noted only relatively minor problems. For example, the reviews of the two nations' 2000 submissions noted that neither submission included information on quality assurance procedures. Although the good practice guidance calls for including such information in the national inventory report, the nations were encouraged, but not required, to follow the good practice guidance for the 2000 submissions. Nonetheless, the experts included the lack of quality assurance documentation as a finding of the reviews. Because the problems noted were relatively minor, the suggestions for improving future submissions constituted refinements rather than recommendations for large-scale changes. For example, the experts' report on the 2000 U.K. submission suggested archiving the documentation supporting the national inventory report in one location or on the Web. Similarly, the report on the desk review of the 2000 U.S. submission suggested that more details on the methods and factors used to estimate emissions for the land-use change and forestry sector would allow more complete assessment of that sector's data. In contrast, the reviews of the German and Japanese submissions found them to be missing some critical components, and the experts' reports made suggestions for improvement that were fundamental in nature. For example, the review of Germany's 2001 submission found it contained only summary-level and trend data; it did not include any of the sector-specific data tables or recalculations of prior years' data called for by the common reporting format. Furthermore, the national inventory report was missing, so the reviewers could not determine whether problems noted in previous inventories had been addressed. Although the review of the Japanese 2000 submission found most of the data required by the common reporting format was included, like the German submission, this one lacked the national inventory report. As a result of these shortcomings, the experts suggested that Germany submit a complete set of data for all of the required years and sectors and that both nations submit the national inventory report. Additional details on the findings of the six expert reviews are contained in appendix I. Although none of the four Annex I nations' latest submissions--for 2003-- had undergone an expert review as of November 2003, Secretariat staff had performed initial completeness checks on each of them. They found that all four nations' submissions contained most of the required data as well as the required national inventory reports. The Secretariat has not assessed any inventories from China and India because, as of November 2003, neither nation had submitted one. The Secretariat assessed Mexico's 2001 submission, but the Secretariat's practice is to issue one report on the findings of its assessments of all the inventories submitted during the year, with few nation-specific details. Therefore, the Secretariat made public little information about the results of its assessments that could be directly tied to Mexico. According to the Secretariat, China and India are preparing their initial inventories, to be submitted as part of their first national communications. Under article 12, paragraph 5, of the Framework Convention, non-Annex I nations' first inventories are due to the Secretariat "within three years of the entry into force of the Framework Convention or of the availability of financial resources" from the developed nations in Annex I. According to the Secretariat, funding was approved for China in May 2000 and for India in December 1999, and the first disbursements of funds took place in November 2001 for China and in July 2001 for India. According to the Secretariat, the due dates for their first greenhouse gas inventories are no later than November 2004 for China and July 2004 for India. Mexico submitted inventories in 1997 and 2001. Although 106 developing nations had submitted their initial inventories as of November 2003, Mexico is the only nation to have submitted more than one. Secretariat staff assessed Mexico's 2001 inventory, along with those of 51 other non- Annex I nations that submitted inventories that year. In keeping with its practice of reporting on its assessments of non-Annex I nations' inventories as a group, the report for 2001 contained only limited details that could be linked specifically to Mexico's inventory. In particular, the Secretariat reported that Mexico had improved its estimates of emissions from the energy, agriculture, and land-use change and forestry sectors. It also reported that Mexico could further improve its inventory by establishing systematic procedures for preparing the inventory annually and by including estimates for the solvent-use sector. Otherwise, the Secretariat reported only generally on the results of the assessments of submissions of the 52 non-Annex I nations' inventories. Mexico's 2001 submission contained estimates for 1994, 1996, and 1998. According to an EPA official who is knowledgeable about Mexico's inventory, the 2001 Mexico inventory is of reasonably high quality, especially considering the limited resources Mexico has dedicated to developing it. According to its submission, Mexico followed the IPCC estimating guidelines and good practice guidance in preparing the inventory. The EPA official further commented that Mexico's 2001 submission is among the best of those of the developing nations, and in some cases--for example, in presentation of its carbon dioxide emissions data--is equal to those of some developed nations. On the other hand, according to that official, Mexico did not (1) comply with the IPCC estimating guidelines in developing the land-use change and forestry sector data, (2) adequately estimate data for the three synthetic gases, or (3) provide adequate documentation explaining the inventory. Furthermore, Mexico developed its two inventories independent of each other, without establishing a process that would systematically make documentation and data additions and revisions as needed. Consequently, in the opinion of the EPA official, it was difficult for Mexico to build upon its previous efforts when preparing its second inventory. As required for the 2003 submissions, the four developed nations categorized their confidence in their emissions data as either high, medium, or low. All four nations reported their confidence in the data as generally high. To improve the usefulness of nations' assessments of data confidence, however, beginning with the 2004 submissions, developed nations must quantify their confidence assessments. As previously explained, the parties to the Framework Convention have constructed an extensive system of estimating and reporting requirements, buttressed by periodic reviews, to help nations produce inventory data that are of high quality. The parties do not attempt, on the basis of the reviews or any other means, to assign a grade or otherwise rate any nation's success in producing high-quality data. However, as one means of helping developed nations identify areas where their data can be strengthened, the parties require each nation to assess its confidence in the accuracy of its own data. Specifically, the nations are required annually to analyze the quality of the data they report (called an uncertainty analysis) for each gas and for each major source of emissions and removals in each of the six sectors. To do this, the nations have been encouraged, but not required, to use the quantitative methods of uncertainty analysis included in the IPCC good practice guidance. Alternatively, they could rely on qualitative means to determine their confidence in these data. In either case, they have been required to report whether they had high, medium, or low confidence in each estimate of emissions of each of the six gases by each major source of those emissions. The nations have not been required to report on their confidence in the accuracy of the inventory data as a whole. The parties did not provide further criteria for nations to use when determining which of the three categories was most appropriate. As required, all four developed nations reported high, medium, or low ratings of confidence in their estimates for their 2001 emissions by source. To determine the confidence each nation had in its inventory data as a whole, we calculated the proportion of each nation's data that corresponded to each of the three rating categories. According to our calculations, all four nations rated their confidence in their inventory data as a whole as generally high, with the high-confidence ratings ranging from about 75 percent for the United States to about 96 percent for Japan. The high-confidence ratings occurred largely because the lion's share of each nation's total emissions is carbon dioxide from fuel combustion, which can be estimated with a relatively high level of confidence. Table 2 shows each nation's ratings for total emissions by gigagrams of carbon dioxide equivalent, which is the unit of measurement used by the parties to the Framework Convention to allow comparisons among greenhouse gases, which differ in their effects on the atmosphere and expected lifetimes. Although the national inventory reports contained some information about the nations' confidence in their data, none of the nations explained the criteria they used to determine the high-, medium-, and low-confidence ratings they reported. In November 2002, the parties decided to require developed nations to use the quantitative methods in the IPCC good practice guidance to develop estimates of data uncertainty beginning with the 2004 submissions. Instead of designating high, medium, or low ratings of confidence, under the new requirements, developed nations must quantify their uncertainty in their emissions estimates for each gas by each major source using 95 percent confidence levels. In addition, they must combine the source uncertainty estimates into a quantified uncertainty estimate for the inventory as a whole and estimate the uncertainty in the trend between the base year and the most recent year. The IPCC good practice guidance provides detailed instructions for nations to follow to produce the quantitative estimates of data uncertainty. The guidance also describes two methods for combining quantitative uncertainty estimates--one consisting of relatively simple statistical calculations that result in a numerical uncertainty estimate, and the other using computer simulation to calculate the estimates. The computer simulation is a more sophisticated method and should result in more accurate estimates; however, according to the EPA official responsible for compiling the U.S. inventory, the computer simulation also is more costly than the simpler method. Because of this, the good practice guidance states that the nations must use the simpler of the two methods to produce their combined uncertainty estimates; in addition, they are encouraged to use the more sophisticated method when sufficient resources and expertise are available. For example, in its 2003 inventory submission, the United Kingdom used both methods from the good practice guidance to quantitatively estimate its confidence in its 2001 emissions data as a whole. Using the simpler method, the United Kingdom reported an uncertainty value of 17 percent for its inventory data as a whole; that is, the United Kingdom was 95 percent confident that total emissions were between 17 percent less and 17 percent more than the total of about 660,452 gigagrams of carbon dioxide equivalent it estimated for the year. In contrast, using the more sophisticated method, the United Kingdom reported an uncertainty value of 13 percent, indicating it was 95 percent confident that total emissions were between 13 percent less and 13 percent more than the year's total estimate. According to the EPA official responsible for compiling the 2003 U.S. inventory, the high, medium, and low categorizations reflect the early days of developing inventories, before the IPCC had developed its good practice guidance on quantitative methods. Prior to the guidance, the parties recognized that nations would vary in their ability to perform quantitative uncertainty analysis. The parties instituted the three-part categorization in an effort to obtain information that was comparable across nations that were using different methods for assessing data uncertainty. The parties have moved to the quantitative methods because the three-part categorization approach yielded limited information about data uncertainty. For example, a nation could have uncertainty estimates of 35 percent and 60 percent but could have categorized both estimates as medium. The quantitative estimates provide information about the uncertainty of the various components of the inventory, thereby helping nations identify areas in which improvements would have the greatest effect on the accuracy of the inventory as a whole. In addition, the quantified estimates make the uncertainty analyses more consistent and understandable across nations. According to the Secretariat, the quantified uncertainty analysis also better enables expert reviewers to determine if nations are targeting their improvements in the appropriate areas. To improve the quality of data on greenhouse gas emissions, the parties to the Framework Convention are refining their requirements for both Annex I and non-Annex I nations. In addition, they are bolstering the review processes for Annex I nations. The changes are to begin to take effect over the next few years. The parties currently have no plans to change the way that non-Annex I nations' inventories are assessed. The parties have revised their requirements for both Annex I and non- Annex I nations, with the changes taking effect over the next few years. The revisions fall mainly into two areas: procedures for estimating emissions and procedures for reporting those estimates. The parties have revised both the estimating and reporting requirements for Annex I nations. Regarding estimating, for example, beginning with the 2004 submissions, Annex I nations will be required to use both the 1996 IPCC estimating guidelines and the 2000 IPCC good practice guidance. Previously, Annex I nations were required to use only the 1996 estimating guidance and were encouraged, but not required, to use the good practice guidance. Regarding reporting, the parties have specified in greater detail than before the information that should be included in Annex I nations' national inventory reports and in the data tables in the common reporting format. For example, nations should include explanations of how they recalculated their previous years' data and, as previously discussed, the methods they used to quantify their confidence in the data in their national inventory reports. In their reports, nations should document that they prepared their estimates in accordance with the IPCC good practice guidance or explain why they did not; for example, an explanation is required if they used a more sophisticated methodology than that specified in the guidance. The nations should also cross-reference the information in the national inventory report to explain the estimates reported in the data tables. Furthermore, Annex I nations must submit their national inventory reports following a specified format designed to facilitate review of the inventories. The parties also revised the reporting requirements for non-Annex I nations that submit inventories in 2003 or later. Non-Annex I nations that had not submitted an inventory prior to 2003 must include data in their initial inventories for either 1990 or 1994 to establish an inventory baseline. Those submitting their second inventories should provide data for 2000 as well. This is in contrast to the requirement that Annex I nations submit data for all years, from 1990 to the present. Similarly, the parties specified that non- Annex I nations should report data for carbon dioxide, methane, and nitrous oxide and encouraged reporting of the other three gases-- hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. In contrast, Annex I nations are required to report data for all six gases. According to the manager of the 2003 U.S. inventory, the estimating and reporting requirements for non-Annex I nations are less demanding to encourage those nations to report because those nations generally have fewer resources available for reporting. In addition, the parties have requested that the IPCC continue to improve its guidance on estimating. Currently, the good practice guidance does not address estimating emissions and removals for the land-use change and forestry sector. According to the EPA official who managed the 2003 U.S. inventory, the IPCC deferred guidance on estimating emissions and removals because it was developing a special report on them, which was subsequently published in 2000. On the basis of that report, the IPCC began drafting new good practice guidance for estimating emissions and removals for the land-use change and forestry sector, which is due to be completed in late 2003. As part of this effort, the IPCC is also refining the data tables for the land-use change and forestry sector. In addition, according to the same EPA official, the IPCC is merging the 1996 guidelines with its good practice guidance and expects to complete the effort by 2007. The parties are strengthening the expert review process for Annex I nations' submissions by conducting more reviews and standardizing the review processes. Beginning with the 2003 submissions, each of the 39 Annex I nations will undergo one of the three types of expert reviews each year: an in-country review once every 5 years and either a desk review or a centralized review in each of the intervening years. This requirement contrasts with the practices of the past 3 years, when the experts performed from 8 to 21 expert reviews in a year. Furthermore, to standardize the reviews, the parties have spelled out, in greater detail than before, the elements that are to be examined during reviews and have developed a standardized format for reporting the results of the reviews. In addition, according to EPA inventory managers, in another effort to make the expert reviews more uniform, the Secretariat is developing a handbook and a training program for the expert reviewers and has specified the composition and responsibilities of the teams of expert reviewers. According to the Secretariat, the parties have no plans to change the assessment process for non-Annex I nations' inventories, but the new reporting guidance for non-Annex I nations would facilitate changes to the assessment process, should the parties decide to institute them. To examine the results of the most recent expert reviews of the greenhouse gas inventories submitted by the four economically developed nations included in our study--Germany, Japan, the United Kingdom, and the United States--we reviewed and analyzed the Secretariat's status reports showing the results of its initial reviews (called stage 1 reviews by the Secretariat) of the most recently submitted inventories (2003). We also reviewed the reports on the parties' most recent expert reviews (called in- depth reviews by the Secretariat) of the four nations' inventories (2000 for Japan, 2000 and 2002 for the United Kingdom, 2000 for the United States, and 2001 for Germany) and related documentation on reporting requirements and review processes issued by the Secretariat. We interviewed officials at EPA who manage the U.S. greenhouse gas inventory and serve as inventory experts for the parties, as well as officials from the State Department's Bureau of Oceans and International Environmental and Scientific Affairs who are responsible for policy issues related to the Framework Convention. In addition, we reviewed and analyzed the limited information provided to us by the Secretariat in response to questions we posed. To describe the results of any assessments of inventories of the three developing nations included in our study--China, India, and Mexico--we reviewed and analyzed the Secretariat's reports on its assessments of inventories submitted by non-Annex I nations, including the latest inventory submitted by Mexico (2001); related documentation on non- Annex I nation reporting requirements and assessment processes; and other Secretariat information documenting which non-Annex I nations have submitted inventories. We also interviewed the officials at EPA and the Department of Energy who are most familiar with the three nations' efforts to compile and report their inventories, as well as the cognizant officials from the State Department. To determine the extent to which the developed nations have confidence in their data, we analyzed the confidence information each nation provided in its 2003 submission. To describe any changes in assessing confidence in the data that are to take effect in the future, we examined documentation from the Secretariat and the relevant sections of the four developed nations' 2003 submissions. To describe the steps the parties are taking to improve the quality of future inventory data and determine when those improvements might be in place, we reviewed and analyzed documentation of the parties' new estimating, reporting, and review requirements; interviewed cognizant EPA officials; and reviewed and analyzed the limited information on this issue submitted to us by the Secretariat in response to questions we posed. We performed our work between November 2002 and November 2003 in accordance with generally accepted government auditing standards. We provided a draft of this report to the Secretary of State, the Administrator of EPA, and the Framework Convention Secretariat for review and comment. EPA provided clarifying comments, which we incorporated where appropriate. We did not receive comments from the State Department or the Framework Convention Secretariat. As arranged with your offices, we plan no further distribution of this report until 30 days after the date of this letter, unless you publicly announce its contents earlier. At that time, we will send copies of this report to interested congressional committees; the Chairmen and Ranking Minority Members, Senate Committee on Appropriations, House Committee on Appropriations, Senate Committee on Governmental Affairs, and House Committee on Government Reform; the EPA Administrator; and the Secretary of State. We will make copies available upon request to other interested parties. This report will also be available at no cost on GAO's Web site at http://www.gao.gov. If you or your staffs have any questions about this report, please call me at (202) 512-3841. I can also be reached at stephensonj@gao.gov. Key contributors to this report are listed in appendix II. The six expert review reports we examined did not follow identical formats; however, they generally highlighted the experts' findings and suggestions for improvement in a summary section at the beginning of each report. The experts noted instances of noncompliance with the reporting requirements. In addition, the experts noted some instances in which the nations did not comply with the Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories, even though following the good practice guidance was not a requirement at the time that the inventories were submitted. The summary-level findings and suggestions for each of the six expert reviews we examined are listed in table 3. In addition to the individuals named above, Simin Ho and Karla Springer made key contributions to this report. Nancy Crothers, Sandra Edwards, Barbara Johnson, Karen Keegan, Andria Key, Charlotte Moore, Chris Moriarity, Katherine Raheb, and Anne Rhodes-Kline also made important contributions. The General Accounting Office, the audit, evaluation and investigative arm of Congress, exists to support Congress in meeting its constitutional responsibilities and to help improve the performance and accountability of the federal government for the American people. GAO examines the use of public funds; evaluates federal programs and policies; and provides analyses, recommendations, and other assistance to help Congress make informed oversight, policy, and funding decisions. GAO's commitment to good government is reflected in its core values of accountability, integrity, and reliability. The fastest and easiest way to obtain copies of GAO documents at no cost is through the Internet. 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Summary:
In 1992, the United States and other parties, including both developed and developing nations, agreed to try to limit dangerous human interference with the climate by participating in the United Nations Framework Convention on Climate Change. The parties agreed, among other things, to report on their emissions of carbon dioxide and five other gases whose buildup in the atmosphere is believed to affect the climate. The parties developed standards for these reports and processes for periodically evaluating the reports. Expert teams selected by the parties review the developed nations' reports; staff of the Framework Convention's administrative arm (the Secretariat) assess developing nations' reports. GAO agreed to describe the results of the most recent reviews and assessments of reports from selected economically developed and developing nations, as well as the parties' plans to improve the reports. For the developed nations, GAO agreed to study four geographically dispersed nations with high levels of emissions--Germany, Japan, the United Kingdom, and the United States. For the developing nations, GAO studied China, India, and Mexico, which also have high emissions levels and are geographically dispersed. These nations are not representative of others; therefore, GAO's findings cannot be generalized. In their most recent reviews, expert teams found that the United Kingdom's 2000 and 2002 reports on greenhouse gas emissions and the United States's 2000 report were largely complete, although the teams noted minor findings, such as the lack of information on quality assurance methods, which the nations were encouraged, but not required, to include in their submissions. In contrast, they found that Germany's 2001 and Japan's 2000 reports lacked critical elements, such as the required documentation that was essential to understanding them. Preliminary checks found that all four nations' 2003 reports were largely complete. Secretariat staff have not assessed inventories from China and India because these nations have not submitted them. According to Secretariat records, China and India plan to submit inventories in February 2004 and November 2003, respectively. Secretariat staff assessed Mexico's most recent inventory, but they reported few details about it because their policy is to consolidate the findings of all the developing nations' inventories submitted during a year. To improve the inventories, the parties are changing the reporting standards and review process. For example, starting in 2004, developed nations must present their inventory reports in a standardized format to facilitate review, and developing nations must report data for more years and gases than before. Also, in 2003, the parties began conducting more rigorous reviews of developed nations' inventories, but no such changes for developing nations are planned.