Over the past two decades, in virtually every area of the planet, researchers from a range of disciplines and many countries have worked together to improve their understanding of the changing global environment and to provide the scientific basis for effective policy responses to these changes.

The international effort is being coordinated in three interrelated areas:

• the Earth's climate system, through the World Climate Research Programme
• the physical, chemical and biological processes that interact to regulate the planet's global environmental systems, through the International Geosphere-Biosphere Programme
• how human society and organizations interact with global changes, through the International Human Dimensions of Global Environmental Change Programme.

Each program coordinates research teams from around the world in core projects addressing specific research challenges. Several core projects are sponsored jointly by two or even all three of the international programs. In some areas, the first generation of core projects has been completed and a second set of projects is being planned, building on the findings to date.

The sponsoring organizations ensure coordination and cost-effectiveness, though there is no common overall management over the three international programs. Each develops a research plan, sets priorities and coordinates a set of core research projects in its specific areas of focus. Individual countries, including Canada, fund research projects under the three programs based on their own national priorities and research strengths.

The World Climate Research Programme (WCRP)
The WCRP was established in 1979 as a joint initiative of three organizations: the International Council of Scientific Unions (ICSU), the World Meteorological Organization (WMO), and the Intergovernmental Oceanographic Commission (IOC) of UNESCO. It coordinates the work of researchers seeking answers to two questions fundamental to the future of human life on the planet:

• To what extent can climate (including climatic variations) be predicted?
• How are human activities affecting the earth's climate?

WCRP research is being pursued through core projects examining several major issues (core project acronyms included in the parentheses):

• the interactions between the tropical oceans and the atmosphere (TOGA, recently completed)
• the circulation and other dynamics of the global ocean (WOCE)
• the nature of climate variability and change (CLIVAR)
• the exchanges of radiation, heat and water within the atmosphere and at the earth's surface (GEWEX)
• the processes that control climate and ice formation in the Arctic (ACSyS)
• the role of stratospheric processes in climate (SPARC).

The International Geosphere-Biosphere Programme (IGBP)
The IGBP was established in 1986 by the ICSU to describe and understand the interactive physical, chemical and biological processes that regulate the total Earth system, the unique environment that this system provides for life, the changes occurring in this system and the manner in which these changes are influenced by human activities.

The IGBP is addressing a range of critical questions through established and proposed core research projects:

• How is the chemistry of the global atmosphere regulated and what are the impacts of changes in its chemical composition? (IGAC and STIB)
• How do the ocean's biogeochemical processes influence and respond to climate change? (JGOFS and GOEZS)
• How will changes in land use, sea level and climate affect coastal ecosystems, and what are the wider consequences? (LOICZ)
• How does vegetation interact with physical processes of the hydrological cycle? (BAHC)
• How will global changes affect terrestrial ecosystems? (GCTE)
• What significant changes in climate and environment occurred in the past and what were their causes? (PAGES)
• How can our knowledge of components of the earth system be integrated and synthesized in a numerical framework that provides predictive capacity? (GAIM)
• How will the global ocean ecosystem respond to and, in turn, affect global change? (GLOBEC)

The International Human Dimensions of Global Environmental Change Programme (IHDP)
Complementing research conducted under the other two international programs, the IHDP fosters activities that seek to describe and understand the human role in causing global environmental changes and the consequences of these changes for society. Established by the International Social Science Council (ISSC) in 1990 (the ICSU is now a co-sponsoring organization), the IHDP addresses four major research questions through its core projects:

• What are the human forces driving global change?
• How are these social processes linked to the physical processes of global change?
• What are the impacts of physical global change processes on human systems, and what are the different sensitivities of various social, political and economic arrangements to these processes?
• What is the potential for adaptation, and what mitigation strategies could different social systems formulate and adopt?

Among the broad questions to be pursued under the IHDP are the social dimensions of resource use; perceptions of the environment; political, economic and social institutions; energy use; industrial growth; land use; and environmental security and sustainable development.

For more information on the above projects, consult the CGCP's Global Change Directory, CIGA