The concept of “Sustainable Development” was adopted during “The Earth Summit” in Rio, in 1992, and The UN “Commission on Sustainable Development” (CSD) was established to review progress achieved towards the implementation of the concept and the entailed “Agenda 21” adopted then. Yet since that time, limited progress was achieved. Many observers stated that the mechanisms for implementation needed reform at all levels: national, regional and international. To this effect, UNEP proposed, in 2008, the “Green Economy” initiative to re-invigurate the drive towards sustainable development and the eradication of poverty. Moreover, the “Green Economy: towards sustainable development and eradication of poverty” was selected as one of the major issues of the upcoming “UN Conference on Sustainable Development” (UNCSD or Rio+20), to be held by the end of 2012 in Rio, along with the topic of “Institutional Reform” of sustainable development mechanisms. This report presents a summary of the outcome of the last cycle of CSD (sessions 18 and 19) including a summary of the contributions of Arab States to these sessions. It also includes a short review of what is expected as a result of these sessions in preparation for Rio+20 Conference. Also, this report presents brief reviews of the concepts of Sustainable Development and Green Economy. It summarizes the challenges and opportunities related to “The Green Economy” linking it to sustainable development and to the eradication of poverty. It also covers the reservations of many developing countries to the concept itself. Finally, the report presents the rationale behind the need for institutional reforms and the proposed alternatives for the UN mechanisms in the area of environment and sustainable development.