The WCRP) Joint Scientific Committee approved the establishment of a new project on Climate and the Cryosphere (CliC) in March 2000. The cryosphere, which includes snow cover, ice sheets and glaciers, sea and freshwater ice and frozen ground, is an integral part of the global climate system with important linkages and feedbacks and is a key component of climate model response to global change. There are also significant environmental and societal issues relating to potential changes in the climate – cryosphere system. The Science and Co-ordination Plan (Allison et al., 2001) describes research and coordination initiatives required to integrate fully studies of the impact and response of the cryosphere to climate variability and change, and the use of cryospheric indicators for climate change detection, within the WCRP. The most important interactions are treated under the following headings: * interactions between the atmosphere, snow and land * interactions between land ice and sea level * interactions between sea ice, oceans, and the atmosphere, and * cryospheric interactions with the atmosphere and the ocean on a global scale. The scientific strategy for a CliC programme is similar in each area of interaction: a combination of measurement, observation, monitoring and analysis, field process studies and modelling over a range of time and space scales. Issues considered to be important include: * the loss of tropical glaciers and ice shelves in the Antarctic Peninsula. the mass balance of the Greenland and Antarctic ice sheets. * the loss of snow and ice in many mountain regions which has important implications for water resources, hydropower, tourism and scenic value. * the potential seasonal opening of the Arctic Ocean due to decreased ice cover and thinning. * changes in seasonal freezing of the ground, in active layer thickness, and in perennially frozen ground extent and thickness. * possible changes in oceanic thermohaline circulation related to ice-ocean interactions and associated risks of abrupt climate change. * changes in seasonal snow cover affecting energy and water budgets.

The CliC Scientific Steering Group has drafted an Implementation Plan that is complementary to other initiatives and draws on the expertise of other organizations. Some elements of the proposed CliC Implementation Plan include the coordination of pole-equator-pole transects for monitoring cryospheric components such as snow line, glaciers and frozen ground, intercomparison of models with respect to their parameterization of cryospheric processes, assessment of the measurement of solid precipitation and snow water equivalent on a global scale, and improvements in the merging of satellite and in situ measurement of cryospheric variables. The draft Implementation Plan is available for comment ( see http://clic.npolar.no). National plans are under development. China has established a national committee for CliC and discussions are underway to establish an advisory committee for a U.S. CliC program. In addition, various national projects directly contribute to CliC. CliC is planned as at least a 15-year program and the SSG is developing an implementation strategy to prioritize the different elements of the plan in terms of their urgency and scientific readiness .