The United States has made significant investments in advancing human knowledge about climate, its role in the environment, and its impact on human activities. Scientists have identified global-scale climate changes, and they are working to ascertain potential consequences and responses.

The U.S. Climate Change Science Program (CCSP) coordinates the scientific activities of some 13 federal government agencies and departments and seeks to provide the United States and the global community with the science-based knowledge to manage the risks and opportunities of change in the climate and related environmental systems.

Richard H. Moss, Ph.D., is the director of the office of the U.S. government's Climate Change Science Program and senior scientist in the Joint Global Change Research Institute at the University of Maryland.

Climate and climate variability play important roles in shaping the environment, natural resources, infrastructure, economy, and other aspects of life in all countries of the world. Potential human-induced changes in climate and related environmental systems, and options proposed to adapt to or mitigate these changes, are also projected to have significant environmental, economic, and societal consequences.

To make informed judgments and decisions, citizens and decision makers in public and private sector organizations need reliable and readily understandable information. To meet this information need, U.S. research efforts strive to develop and provide information on variability and change in climate and related systems.

Substantial Investment in Research

Over roughly the past 15 years, the United States has invested heavily in scientific research, monitoring, data management, and assessment for climate change analyses to build a foundation of knowledge for decision making. To date, more than $20 billion of research funding has been provided by U.S. agencies and departments.

In 1989, President George H.W. Bush established the interagency U.S. Global Change Research Program (USGCRP), which was institutionalized in the U.S. Global Change Research Act in 1990. The rationale for establishing the program was that global change issues are so complex and wide ranging that they extend beyond the mission, resources, and expertise of any single agency, requiring instead the integrated efforts of scientists and researchers working in or supported by multiple departments.

During its first decade, USGCRP-supported research demonstrated that global-scale changes are taking place in Earth's environment and that human activities contribute to these changes. Alteration of atmospheric composition, stratospheric ozone depletion, climate change, and land cover change were among the phenomena detected.

The USGCRP also conducted research into Earth's natural variability and laid the basis for developing predictions of shifts in phase of the El Niño-Southern Oscillation (ENSO)-a natural fluctuation of ocean currents that has major effects on global weather and natural hazards-and identifying other climate oscillations.

USGCRP-supported activities developed and deployed a series of remote sensing satellites that form the basis of a global environmental observing system being developed through the Global Earth Observation System of Systems (http://iwgeo.ssc.nasa.gov). A suite of climate and Earth-system models has been developed under the USGCRP to integrate these observations, to analyze global change processes, and to project changes and their potential consequences.

In 2001, President George W. Bush launched the Climate Change Research Initiative "to study areas of uncertainty and identify priority areas" for research. In 2002, the president created a new Cabinet-level management structure to oversee climate change science and technology programs.

The Climate Change Science Program (CCSP) is the part of that structure that coordinates the scientific investments and activities of 13 participating federal government agencies and departments (http://www.climatescience.gov).

CCSP Vision, Mission, and Goals

The seriousness of climate variability and change, and the unique role that science can play in helping determine society's course, give rise to CCSP's guiding vision: A nation and the global community empowered with the science-based knowledge to manage the risks and opportunities of change in the climate and related environmental systems.

The core precept that motivates CCSP is to apply the best possible scientific knowledge in managing climate variability and change and related aspects of global change. The CCSP mission is thus to facilitate the creation and application of knowledge of Earth's global environment through research, observations, decision support, and communication.

CCSP will add significant integrative value to the individual Earth and climate science missions of its 13 participating agencies and departments and their national and international partners, coordinating research and integrating and synthesizing information to achieve results that no single agency, or small group of agencies, could attain.

CCSP has five goals related to addressing society's information needs.

Goal 1: Improve knowledge of Earth's past and present climate and environment, including its natural variability, and improve understanding of the causes of observed variability and change.

Climate conditions change significantly over time. CCSP research will improve understanding of natural oscillations in climate on timescales of weeks to centuries, including improving and harnessing ENSO forecasts. Improved observations, analysis, and modeling will sharpen qualitative and quantitative understanding of how and why climate is changing and will determine whether changes in the frequency or intensity of extreme climate events (e.g., droughts) lie outside the range of natural variability.

Goal 2: Improve quantification of the forces bringing about changes in Earth's climate and related systems.

Burning of fossil fuels, changes in land cover and land use, and industrial activities produce greenhouse gases and aerosols, altering the composition of the atmosphere and physical and biological properties of Earth's surface. These changes have important climatic effects, some of which can be quantified only poorly at present.

Research conducted through the CCSP will increase confidence in our understanding of characteristics of greenhouse gases and aerosols, their long-range atmospheric transport and removal from the atmosphere, as well as their interactions with global climate, ozone in the upper and lower layers of the atmosphere, and regional-scale air quality.

Research will also improve quantification of interactions among the carbon cycle, other biological/ecological processes, and land cover and land use to better project atmospheric concentrations of key greenhouse gases and support improved decision making. The program will also improve capabilities for developing and applying emissions scenarios in research and analysis, in cooperation with the multiagency Climate Change Technology Program.

Goal 3: Reduce uncertainty in projections of how Earth's climate and related systems may change in the future.

Uncertainty exists regarding precisely how much climate will change overall and in specific regions.

A primary CCSP objective is to develop the information and scientific capacity needed to sharpen qualitative and quantitative understanding through interconnected observations, data assimilation, and modeling activities. CCSP-supported research will address basic climate system properties and a number of "feedbacks" or secondary changes that can reinforce or dampen the initial effects of greenhouse gas and aerosol emissions and changes in land use and land cover.

The program will also address the potential for future changes in extreme events and possible rapid or discontinuous changes in climate. The CCSP will build on existing U.S. strengths in climate research and modeling.

Goal 4: Understand the sensitivity and adaptability of different natural and managed ecosystems and human systems to climate and related global changes.

Seasonal-to-annual climate variability has been shown to impact ecosystems and human life. Improving our ability to assess potential implications of changes in climate and environmental conditions on ecosystems and human systems could help governments, businesses, and communities reduce damages and seize opportunities by adapting infrastructure, activities, and plans.

CCSP research will examine the interactions of interdependent changes and effects. Examples are the carbon dioxide fertilization effect, in which some plants' rates of photosynthesis rise with increases in carbon dioxide; changes in landscapes that affect water resources and habitats; and changes in frequency of fires or pests.

CCSP research will improve methods for integrating our understanding of potential effects of different atmospheric concentrations of greenhouse gases, and develop methods for aggregating and comparing potential impacts across sectors and locations.

Goal 5: Explore the uses and identify the limits of evolving knowledge to manage risks and opportunities related to climate variability and change.

Over the past decade, the scientific and technical community has developed products to support the management of risks and opportunities related to climate variability and change. CCSP will foster more studies and encourage evaluation and learning from these experiences to develop processes and products that use knowledge to the best effect, with the ultimate objective of supporting policymaking, planning, and adaptive management.

These resources will communicate critical information and explore the implications of uncertainty for decision making through a variety of means, including observational data, model products, scenario analysis, visualization products, and scientific syntheses and assessments.

International Collaborations

Climate variability and change are intrinsically international in scope. Effective research thus requires international cooperation-cooperation among scientists and research institutions and governmental agencies. U.S. scientists, institutions, and agencies are at the forefront of such international cooperation, reflecting the leadership role of U.S. climate science.

CCSP is a leader in a global network of active and engaged international research scientists and institutions, including the International Geosphere-Biosphere Programme (http://www.igbp.kva.se), the International Human Dimensions Programme (http://www.ihdp.uni-bonn.de), the World Climate Research Programme (http://www.wmo.ch/web/wcrp/wcrp-home.html), Diversitas (http://www.diversitas-international.org), and the Earth Science System Partnership (http://www.ess-p.org). The United States has also developed bilateral and regional partnerships to advance the science of climate change, enhance the technology to monitor and reduce greenhouse gases, and help developing countries through capacity building and technology transfer.

The CCSP will continue to interact with these organizations and partnerships directly and through support to U.S. scientists providing dynamic scientific leadership.

As a leader in climate change science, the United States assumes responsibility for participating in and providing data to international assessments such as those on ozone, biodiversity, ecosystems, and climate.

An Announcement

As part of its commitment to develop partnerships with those who provide and use climate information around the world, the U.S. CCSP invites participation in a workshop, Climate Science in Support of Decision Making, to be held in the Washington, D.C., area November 14-16, 2005.(http://www.climatescience.gov/workshop2005/default.htm).

We encourage the attendance of representatives of international organizations and countries interested in learning from U.S. experiences or helping shape future U.S. activities related to the application of climate information.