The Global Climate Observing System (GCOS) has prepared an Implementation Plan for the Global Observing Systems for Climate in support of the UNFCCC and has presented this plan to the Subsidiary Body for Science and Technological Advice at COP 10 Buenos Aires in December 2004. The plan is based on an international assessment -Second Report on the Adequacy of Global Climate Observing Systems - for the UN Framework Convention on Climate Change (UNFCCC). It contains actions suggested for Countries their agencies together with needed coordination actions within International bodies, programs, and other involved bodies. In accord with the requests of the UNFCCC at COP 9 this Implementation plan has been prepared by GCOS in coordination with the production of the wider Implementation Plan of the GEO.