This note describes the Green Climate Fund design process to date, and outlines key points of tension. The decision at the COP17 in Durban, South Africa, to adopt a governing instrument for the Green Climate Fund (GCF), as well as a transitional process for its full operationalisation by 2014, was a key component of the "Durban Package". Without agreement on the GCF, the "African COP" would have been considered a failure. The GCF was designed by a Transitional Committee (TC) in 2010 with the goal of becoming the main multilateral financing mechanism to support climate action in developing countries. Under a compromise decision reached at the last minute in Durban, the new GCF will be a legally independent institution with its own separate secretariat and the World Bank as its interim trustee, but functioning under the guidance of and accountable to the COP. How to define and shape this relationship between the GCF and the COP will be the first order of business for the new GCF Board, which could meet as early as end of April. An Interim Secretariat with UNFCCC and GEF staff will provide support for the 24 new Board members with equal representation of developed and developing countries. Since the Durban Package did not reach any agreement on long-term sources of climate financing, the biggest challenge for the GCF will be to secure adequate and sustained funding. Otherwise, the GCF is in danger of becoming a beautifully articulated, but largely empty shell. Substantial, financial pledges made quickly by contributing countries would be necessary to show broad political support for the GCF and secure its viability; whether this actually happens in 2012 remains to be seen.