Biennial Transparency Reports (BTRs) offer unique insights into the diverse capacities, achievements and challenges of Commonwealth member countries in meeting their transparency obligations under the Paris Agreement. By reviewing them alongside UNFCCC data and country-level survey and interview feedback, this report identifies best practices and evidence of progress, and provides recommendations for how the 'transparency gap' can be closed ahead of the next BTR cycle.
The first BTRs (BTR1s), due by 31 December 2024 under the Paris Agreement’s Enhanced Transparency Framework, represented a landmark moment in global climate accountability. For the Commonwealth, a family of 56 nations spanning developed, developing, least developed and small island developing states, these reports offer a unique window into the diverse capacities, achievements and challenges of member countries in meeting their transparency obligations.
Of the 56 Commonwealth member countries, 23 (41 per cent) submitted their BTR1 by the deadline. While this reflects genuine progress, particularly among developed members and several pioneer developing countries, it also reveals significant capacity and resource gaps that must be addressed as the reporting cycle continues.
This report draws on a systematic desk review of 23 Commonwealth BTR1 submissions, a global synthesis report by the UN Framework Convention on Climate Change (UNFCCC) Secretariat and country-level survey and interview feedback. It identifies best practices, recommends targeted interventions and calls on the Commonwealth to deploy its unique networks to close the transparency gap ahead of the next BTR cycle. Major findings from the study include the need to strengthen the Technical Expert Review process under the UNFCCC Secretariat by addressing gaps in financing and the limited availability of trained reviewers.
The Commonwealth Secretariat, with partners, supported a UNFCCC Secretariat-led pilot of a centralised BTR review for African LDCs in Kigali in May 2026. This model demonstrated how co-ordinated, regional approaches and resource-pooling can improve the quality of BTR reviews, reduce costs and strengthen peer learning. Building on this success, the Commonwealth calls on partners, donors and the UNFCCC Secretariat to scale up financing for reviews and expand trained reviewer capacity to ensure timely TERs. Countries cannot improve without timely feedback, and the next BTR cycle is already underway.
Key findings
- Only 41 per cent of Commonwealth members submitted BTR1 on time against a global average of approximately 45 per cent of parties globally, indicating a Commonwealth-specific capacity gap.
- Africa and the Indo-Pacific showed the largest reporting gaps by the December 2024 deadline, with 12 and 11 non-submissions respectively.
- Data gaps, institutional capacity constraints and financial barriers were the three most universally cited challenges.
- The Global Environment Facility (GEF) provided about US$14.9 million in funding for BTR preparation to Commonwealth member countries under the Umbrella Programme for Preparation of National Communications and Biennial Transparency Reports to the UN Framework Convention on Climate Change. However, disbursements were often delayed and insufficient for small island developing states (SIDS) and least developed countries (LDCs).
- Guyana was the second Party globally and the first SIDS to submit a BTR, a notable achievement demonstrating that early action is possible even for developing countries.
- Gender mainstreaming was present in 64 per cent of submissions; Indigenous Peoples’ perspectives remain significantly underrepresented.
- Survey feedback from Mauritius and Grenada reveals contrasting experiences: Mauritius succeeded through robust institutional planning despite a five-month timeline; Grenada faced institutional co-ordination delays.
