Planning of International CLIVAR began in 1993. The project commenced in 1995, and it is anticipated to continue beyond 2010. CLIVAR was established based on the success of the Tropical Ocean Global Atmosphere (TOGA) project and the progress of the World Ocean Circulation Experiment (WOCE) for advancing scientific understanding of the ocean and atmosphere-ocean interactions. It also was based on the research needs expressed in the Intergovernmental Panel on Climate Change (IPCC) scientific assessment reports. CLIVAR was conceptualized as a follow-on project for continuing the study of ocean dynamics and coupled ocean-atmosphere dynamics as they relate to climate (WCRP, 1995). As defined by the CLIVAR Science Plan, the objectives of CLIVAR are to:

• describe and understand the physical processes responsible for climate variability and predictability on seasonal, interannual, decadal, and centennial time-scales through the collection and analysis of observations and the development and application of models of the coupled climate system in cooperation with other relevant climate-research and observing programs;

• extend the record of climate variability over the time-scales of interest through the assembly of quality-controlled paleoclimatic and instrumental data sets;

• extend the range and accuracy of seasonal to interannual climate prediction through the development of global coupled predictive models; and

• understand and predict the response of the climate system to increases of radiatively active gases and aerosols and to compare these predictions to the observed climate record in order to detect the anthropogenic modification of the natural climate signal.

These objectives are compartmentalized into three main threads of research based on the various timescales and catalysts of climate change:

• Global Ocean-Atmosphere-Land System (GOALS), which focuses on seasonal to interannual climate variability and predictability of the global ocean-atmosphere-land system;

• Decadal to Centennial Climate Variability (DecCen), which focuses on the mechanisms of climate variability and predictability on decadal to centennial time scales with a special emphasis on the role of the oceans in the global coupled climate system; and

• Anthropogenic Climate Change (ACC), which focuses on the response of the climate system to anthropogenic climate change.

Through these areas of research, the International CLIVAR Project aims to help understand the physical processes that are responsible for climate variability on all time scales through the collection and analysis of observations by using coupled climate system models in cooperation with other climate research and observing programs. Focus also is given to extending existing climate records by using quality controlled paleoclimate and instrumental data sets.

The planning, oversight, and coordination of International CLIVAR are the responsibility of the CLIVAR Scientific Steering Group (SSG), which is appointed by and reports to the Joint Scientific Committee of the WCRP. To facilitate its work, the SSG has many subcommittees and panels which