The Convention established two permanent subsidiary bodies: the Subsidiary Body for Scientific and Technological Advice (SBSTA) and the Subsidiary Body for Implementation (SBI). These bodies give advice to the COP and each has a specific mandate. They are both open to participation by any Party and governments often send representatives who are experts in the fields of the respective bodies.

As its name suggests, the SBSTA’s task is to provide the COP with advice on scientific, technological and methodological matters. Two key areas of work in this regard are promoting the development and transfer of environmentally-friendly technologies, and conducting technical work to improve the guidelines for preparing national communications and emission inventories. The SBSTA also carries out methodological work in specific areas, such as the Land Use, Land-Use Change and Forestry (LULUCF sector), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), and adaptation and vulnerability. In addition, the SBSTA plays an important role as the link between the scientific information provided by expert sources such as the IPCC on the one hand, and the policy-oriented needs of the COP on the other. It works closely with the IPCC, sometimes requesting specific information or reports from it, and also collaborates with other relevant international organizations that share the common objective of sustainable development.

The SBSTA and SBI work together on cross-cutting issues that touch on both their areas of expertise. These include capacity building, the vulnerability of developing countries to climate change and response measures, and the Kyoto Protocol mechanisms.

The SBSTA and the SBI have traditionally met in parallel, at least twice a year. When they are not meeting in conjunction with the COP, the subsidiary bodies usually convene at the seat of the secretariat.

Source: http://unfccc.int/essential_background/convention/convention_bodies/items/2629.php