Chapter 06 · Governance & regulationRegulation & International Instruments
Biennial transparency report (BTR)
Definition
The reporting vehicle of the Paris Agreement's enhanced transparency framework (ETF, Article 13), submitted by all Parties every two years — the first by 31 December 2024, the second by 31 December 2026. Per the modalities, procedures and guidelines (decision 18/CMA.1), BTRs cover the national inventory report, information to track NDC progress, policies and measures, climate impacts and adaptation, and support provided, mobilised, needed and received, using common tabular formats.
References
Two-year cycle; first deadline 31 Dec 2024; MPGs (decision 18/CMA.1) content; CRT/CTF formats; SIDS/LDC discretion.
ETF operationalisation 2024; BTR role in the five-year ambition cycle and global stocktake; capacity challenges.
Overview
What it means
The BTR replaces the differentiated BR/BUR system with one format for all, plus built-in flexibility for developing countries that need it; small island developing states and least developed countries may report at their discretion. Reports undergo technical expert review and facilitative, multilateral consideration of progress.
Content includes textual chapters plus common reporting tables (inventories) and common tabular formats (NDC tracking and support), with optional technical annexes for REDD+ results.
How it is used
BTRs feed the global stocktake, inform successive NDCs, and create the public record against which countries' climate performance is judged. The first round revealed both achievement and strain: many developing countries reported for the first time, with capacity support from initiatives such as the Partnership on Transparency in the Paris Agreement.
Why it matters
The Paris Agreement runs on trust built through transparency; the BTR is its core accountability instrument — the mechanism by which "pledge and review" becomes verifiable.