Deforestation is responsible for the largest share of additional carbon dioxide (CO 2 ) released to the atmosphere due to land use changes, approximately 20% of total anthropogenic greenhouse gas (GHG) emissions annually. Deforestation results in carbon emissions when trees and underlying vegetation are burning or decomposing. Deforested areas that are later cultivated also release carbon to the atmosphere when soil carbon is oxidized. Further, deforested areas converted to other land uses (e.g., pastures) might sequester less carbon than forests, enabling greater levels of CO 2 in the atmosphere. Forests store approximately 45% of terrestrial carbon, and in the 1990s were estimated to remove 2.6 billion tons of carbon (mtCO 2 ) from the atmosphere per year; this sequestered amount is equivalent to approximately 33% of anthropogenic carbon emissions from fossil fuel and land use changes. Data on carbon sequestration and emissions are not available for many regions, making global estimates uncertain. Much of the deforestation responsible for CO 2 releases occurs in tropical regions, specifically in developing countries such as Brazil, Indonesia, and the Democratic Republic of the Congo. Tropical forests store approximately 25% of the total global terrestrial carbon. Scientists estimate that tropical deforestation and other land use changes may have been responsible for releasing approximately 1.5 billion metric tons of CO 2 per year to the atmosphere during the 1990s, and may be contributing similar amounts of carbon to the atmosphere today. Some contend that deforestation due to logging might result in small carbon emissions because timber converted into products will not release CO 2 immediately. Others disagree, stating that the percentage of wood transformed into wood products is probably small in tropical and temperate regions. Deforestation rates vary across the world, yet are generally higher in tropical regions (see Figure 1 ). By continent, the highest rate of net forest loss is in South America, which lost approximately 4.3 million hectares (ha) of its forest (0.5%) annually from 2000 to 2005. This is followed by Africa, which lost approximately 4.0 million ha (0.6%) of its forest annually during the same period. North America (including Central America), in contrast, lost approximately 333,000 ha (0.05%) annually from 2000-2005; and in China, there was a reported gain of 4.1 million ha of forest annually (2.2%) during the same period, primarily due to large-scale afforestation efforts. Figure 1. Global Change in Forest Cover, 2000-2005Source: The U.N. Food and Agriculture Organization, Global Forests Resources Assessment (Rome, Italy: 2006), 320 pp.Note: Dark lines represent the Tropics of Cancer and Capricorn. The role of forests in the carbon cycle and the extent of deforestation and its impact on GHG emissions are primary reasons deforestation is addressed in climate change legislation. Many experts contend that protecting forests or preventing deforestation may be less expensive than other technologies to reduce CO 2 emissions, and provide other environmental and socioeconomic benefits such as preserving biodiversity. Others contend that increasing carbon sequestration through restoration and preventing deforestation, though compelling in theory, might be challenging and more expensive in practice. Bills that address deforestation propose in their findings that international deforestation is a major contributor to GHG emissions, and that foreign countries with forests have a role in preventing deforestation and engaging in restoration and afforestation activities. Some argue that congressional intent to address deforestation is misplaced with funding initiatives to prevent deforestation in foreign countries. They question the ability of some foreign countries to implement and monitor forest restoration and preservation programs, and the potential value to the United States of implementing these programs. Further, they argue that funds should be focused on domestic efforts to address forest restoration and carbon sequestration technologies. This CRS legislative analysis covers key issues and policies addressed by three selected climate change bills introduced in the 110 th Congress that include international deforestation: S. 3036 , H.R. 6186 , and H.R. 6316 . These bills would address deforestation and climate change by authorizing funding to eligible foreign countries to reduce deforestation, increase forest restoration and afforestation, and improve forest management. Forest carbon activities (or deforestation reduction activities) would be supported by programs proposed in the legislation. The definitions of forest carbon activities are specific, and include: activities directed at reducing GHG emissions from deforestation and forest degradation; activities that increase sequestration through restoration of forests and degraded land that has not been forested prior to restoration; and increasing sequestration through afforestation and improved forest management. Restoring recently deforested tracts is not an eligible forest carbon activity under these bills. The intent to exclude this activity might be to dissuade countries from deforesting new areas with the expectation of financial assistance for restoration afterwards. For example, it has been argued by some that countries could receive the economic benefits from selling tropical timber in the international market, and then potentially receive international assistance to replant without requiring countries to assume the economic costs of preventing deforestation. This would subsidize tropical timber production with perverse effects in both trade and GHG emissions. However, some argue that excluding recently forested areas from the program might neglect the potential for restoration in large areas of tropical and temperate forests. Indeed, some may contend that previously forested land might offer the best ecological conditions for successful restoration. For example, in tropical forests, where soils are fragile, several studies report that reforestation is most successful soon after deforestation, and sometimes is least successful when lands have been used for grazing, agriculture, or other human-related activities for several years. Most deforestation and net forest carbon emissions occur in developing countries. Some of these countries have little capacity to undertake forest carbon activities and effectively monitor and measure results. All three bills acknowledge this possibility and authorize a set of eligibility requirements for countries that could participate in their programs. Countries eligible for receiving financial assistance under forest carbon programs roughly fall into two categories: Category Iâcountries with a demonstrated capacity to monitor and measure carbon stocks; capped GHGs; a GHG reduction program or an emission reduction plan for the forest sector; and data on natural forest carbon stocks; and Category IIâcountries that need assistance to achieve the eligibility requirements of Category I. (These would be countries that have demonstrated a commitment to conduct preparatory activities to build their capacity to engage in deforestation or forest degradation activities, or need to develop the capacity to measure and monitor forest carbon changes.) H.R. 6186 and H.R. 6316 distinguish these two categories and would provide funding for both categories; S. 3036 includes only countries under the first category as eligible. Allocation for funding countries under each category varies among the bills. For international forest activities, countries under the first category would receive all funds provided by S. 3036 , at least 60% of the funds provided by H.R. 6186 , and up to 50% of the funds provided by H.R. 6316 . The percentages of funding for countries in each of the two categories does not change over time, yet presumably the intent of the policy is to assist countries in Category II to reach Category I status. Some policies support standards for forest carbon activities. All three bills provide for the Administrator of the U.S. Environmental Protection Agency (EPA), along with other agency heads, to develop standards for forest carbon activities. These standards include implementing activities according to widely accepted sustainable environmental practices, promoting native species and ecosystems, promoting fair compensation, and involving public and indigenous participation and consent. These standards address, in part, potential negative collateral effects of forest restoration and afforestation activities (e.g., unfair treatment of indigenous people who use forest resources, and the introduction of non-native species). The bills also require that forest carbon activities be "real, permanent, additional, verifiable, and enforceable, with reliable measuring and monitoring." (See Table 1 for definitions; also see CRS Report RL34560, Forest Carbon Markets: Potential and Drawbacks , by [author name scrubbed] and [author name scrubbed].) Some contend that deforestation and climate change legislation should integrate forest carbon activities with existing federal programs. This would provide established infrastructure for programs, offer a framework for implementation and monitoring, and avoid duplication with other initiatives. Others counter by suggesting that existing programs are not broad enough to address all forest types and all potentially eligible countries with forests. None of the bills attempts to integrate forest carbon activities with existing U.S. international forestry programs. The U.S. government is involved in several international programs that address forest degradation and deforestation. Particular programs include the International Tropical Timber Organization, the Tropical Forest Conservation Act, and two regional U.S. initiatives. The International Tropical Timber Organization (ITTO) was founded in 1986 because of concerns over tropical deforestation. The organization has 60 members (including the United States) that together have about 80% of the world's tropical forests and conduct 90% of the global tropical timber trade. ITTO promotes sustainable forest management and forest conservation strategies, and assists tropical member countries to adopt such strategies in timber harvesting projects. The Tropical Forest Conservation Act (TFCA; P.L. 105-214 ; 22 U.S.C. Â§2431) authorizes debt-for-nature transactions, where developing country debt is exchanged for local funds to conserve tropical forests. Conservation funds (in local currency) from these transactions are deposited in a tropical forest fund for each country. Interest earned from this principal balance and the principal itself is usually given in the form of grants for tropical forest conservation projects.