There are two reporting approaches for cities involved in the Global Covenant of Mayors for Climate and Energy: (1) the carbonn Climate Registry (cCR) and (2) the Carbon Disclosure Project (CPD). Both carbonn and the CDP are recognised reporting platforms for local governments joining or observing the Compact of Mayors. The cCR is also the designated central repository of the Compact of Mayors, meaning Compact data reported to the CDP will be fed into the cCR for aggregation. The cCR is open for voluntary reporting to all levels of governments, from towns and cities to states, regions and provinces. The cCR has been designed to support and facilitate vertical integration, encouraging local governments within the same geographic region to report, also ensuring that data is not double-counted when aggregated. The cCR is managed by the Bonn Center for Local Climate Action and Reporting (carbonn® Center) based in Bonn, Germany, hosted by the ICLEI World Secretariat.
ICLEI Oceania provides direct support for reporting program cCR, which contains reporting numerous programs and initiatives including corporate and community inventories, renewable energy, transport, procurement and biodiversity. However, at this stage ICLEI Oceania provides only limited support for CDP reporting.