Human-driven climate change, once considered a topic only for scientific research, has evolved into a policy debate. Congressional proposals have identified numerous actions aimed at closer observation and analysis, mandatory pollution control, financial assistance for technological change, adaptation to cope with changes, and a host of additional policy options. Despite calls to expand federal funding to address climate change, federal budgeting overall faces increasingly stark choices among competing fiscal demands. Federal funding for climate change activities was enacted at $6.37 billion for FY2008; adding in the effects of tax incentives, the budgetary impact of climate change-related activities totaled $7.73 billion for FY2008. For FY2009, funding continues at or below those levels through March 6, 2009 under a Continuing Resolution ( P.L. 110 - 329 ). In some cases, the Continuing Resolution may have sustained funding to many climate change programs at a higher level than President Bush's FY2009 request, since many had been proposed to bear cuts. Tax incentives for renewable energy and other similar incentives were passed late in 2008 and the uncertainty may have affected the budgetary impacts of those incentives in FY2009. As the 111 th Congress evaluates the value of past funding and future priorities to address climate change, this report provides an overview of federal funding and tax incentives in the context of Presidential goals from 2001 through 2008, as well as legislative requirements for these programs. With a new Administration, the context for climate change funding will change: President Barack Obama has outlined a new set of policies, including a goal to return U.S. greenhouse gas (GHG) emissions to their 1990 levels by the year 2020, to reduce GHG emissions by 80% below 1990 by 2050, and to achieve these goals through a system of emission caps and trading. As President-elect, Obama stated, on December 15, 2008, that "the effort before us will demand coordination across the government, and my personal engagement as President." To assist with these, he has designated former EPA Administrator Carol Browner to be Assistant to the President for Energy and Climate Change. It remains to be seen how his goals and new leadership in the White House will translate into funding proposals and program alignment. In 2002, President George W. Bush announced a goal to cut the U.S. greenhouse gas (GHG) intensity—the quantity of greenhouse gases emitted per unit of economic activity (GDP)—by 18% through 2012. In parallel, he directed U.S. programs addressing climate change to aim at: reducing scientific uncertainties; advancing development and introduction of energy efficient, renewable, and other low- or non-emitting technologies; and improving standards for measuring and registering GHG emission reductions. On April 16, 2008, President Bush announced a new national goal for climate policy—to halt increases in U.S. emissions of GHG by 2025. Emissions would begin to decline thereafter "so long as technology continues to advance." According to President Bush, the United States would achieve this goal by regulatory measures and market incentives to encourage use of clean technologies. Presidential requests for funding have been linked only in a general way to achieving stated climate change policy goals. Specific outcome-oriented performance targets have been set for some programs, such as for greenhouse gas reductions achieved by the Environmental Protection Agency's and the Department of Energy's Energy Star programs, and several other voluntary partnerships. However, quantitative greenhouse gas, science, or technology performance targets are not identified for most of the requested climate-related funding. Clearer relationships among programs, their funding, and their contributions to meeting measurable climate change goals may be considered by the Obama Administration and the 111 th Congress, especially if GHG targets are legislated as proposed in a number of bills. The appropriation of funds by the Congress alters the total amount and distribution of funding requested by the President to address climate change across agencies and activities. Because most Congressional scrutiny of specific funding, and primary choices, occurs in appropriations subcommittees—further altered by Congressionally directed funding—the appropriations process has not facilitated a broad view of over-arching climate change policy goals and priorities, or consistency with goals across agencies and diverse activities. Enhancing an over-arching vision and prioritization would require greater coordination across subcommittees or at the committee level than typically occurs. Evidence of human influence on the Earth's climate and its potentially catastrophic impacts gained the attention of some Members of Congress by the 1980s. Congress enacted a scientific research program in 1990, and U.S. federal funding subsequently expanded to better understand and address the phenomenon. Both the amounts and purposes of funding for climate change efforts have evolved since 1990. This report describes federal funding of climate change activities across 14 agencies. Most emphasis is on changes from the enacted FY2007 and FY2008 levels to President Bush's FY2009 request. A Continuing Resolution ( P.L. 110 - 329 ) extended the FY2008 enacted levels through March 6, 2009, which is in some cases higher than the levels requested. Some longer historical perspective is provided where data are available. As this report discusses, the availability and clarity of funding information continues to impede full understanding of the federal effort and its effectiveness, and so the estimates provided in this report are best viewed with caution. In addition, the limited political agreement that has evolved around climate change in the United States has resulted in packaging of all activities as research on science or technologies, or international assistance. This emphasis on research may not adequately characterize the actual work and evolving priorities—especially if calls for greater action on GHG abatement, impacts assessment, and adaptation are answered by federal programs and incentives. There has been an historic emphasis on climate change science within the overall U.S. effort to address climate change. Concerns about climate change first issued from the research community. Even as public concern rose, some decision-makers emphasized improving the science in order to make wise policy decisions. Some observers expressed concern that such emphasis on uncertainties and the need for additional scientific research were a rationale not to undertake more concrete mitigative or adaptive actions to address climate change. Nonetheless, there has been a long-standing consensus that continued scientific research on climate change, its impacts and possible adaptation strategies is desirable. Funding levels for climate change increased rapidly from 1989 to 1995, but have generally declined for climate change science since then (when amounts are adjusted for inflation). By the mid-1990s, scenario analyses had made clear that effectively avoiding human-induced climate change would require major changes in energy and other technologies in use. Not surprisingly, another consensus emerged surrounding federal support to advance technologies that allow a transition to a lower greenhouse (GHG)-emitting society without compromising economic well-being. The growing set of activities and funds to support "clean" technologies were packaged as a second major component of the climate change effort by President William J. Clinton for FY1997 as the Climate Change Technology Initiative, and then by President George W. Bush for FY2003 as the Climate Change Technology Program (CCTP). The technology programs have grown to be about two-thirds of all climate change funding. (Budget data are insufficient at this time to analyze the historical funding prior to FY1998.) A third point of broad agreement—and associated funding—has been that the developing countries would need assistance—financial and technical—to adopt less emitting economic paths than those followed by the United States and other industrialized countries. In 1992, the United States and other developed countries committed to providing such assistance under the United Nations Framework Convention on Climate Change. In association with that treaty, in 1992, President George H.W. Bush established a two-year, $25 million Country Studies Program to build the capacities of developing and transition countries to assess and implement climate change policies. Most funding for international assistance has been through the Agency for International Development (US AID), and has generally declined since the late 1990s, due variously to Executive Branch decisions and Congressional opposition. This report provides an overview of climate change funding in three major climate change program areas (science, technology, and international assistance) as well as tax provisions that may encourage reductions in greenhouse gases. Increasingly, there are overlaps and gaps among these program areas. Alternative ways to categorize the funding might better serve Congressional decision-making. Though limited by data, this report provides preliminary analysis of the federal effort—for example, by type of activity or by types of technologies supported. The report also identifies several legislative issues related to federal funding for climate change programs and activities. Table 1 shows new federal budget authority enacted for FY2001 through FY2008 and the FY2009 request, in nominal dollars as reported by the Office of Management and Budget (OMB), and in constant 2007 dollars only for the annual totals, adjusted for inflation by CRS. While information has not been reported yet for FY2009, a Continuing Resolution (CR) ( P.L. 110 - 329 ) extended the FY2008 enacted levels through March 6, 2009 for almost all climate-related programs. The CR continues funding in some cases at levels higher than requested, and in some cases, lower that the request. The Bush Administration has grouped all funding into three major program areas: the Climate Change Science Program (CCSP), the Climate Change Technology Program (CCTP), and International Assistance. Funding has wavered through the years, in total and in each of the program areas. Notable increases occurred in the FY2008 enacted and FY2009 proposed funding, largely for new satellites, nuclear energy, and international technology financing. Understanding the level of effort over time is obscured by changes in the levels of aggregation, scope of programs reported, and methods of budget accounting. (See discussion in the Box 3 , Clarity and Consistency of Reporting of Climate Change Funding.) In addition to budget authority for CCSP, CCTP, and International Assistance, the federal government offers a variety of tax incentives to encourage reductions in greenhouse gas (GHG) emissions.