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Behind the Scenes at SB62: Inside the 2025 Bonn Climate Change Conference

© Sarah Thompson

By Sarah Thompson, PhD Candidate, Université libre de Bruxelles and Senior Research Programme Manager, European Chair for Sustainable Development and Climate Transition, Sciences Po, and Lindley Saffeir, Research Assistant, European Chair for Sustainable Development and Climate Transition, Sciences Po

Over the last two weeks (16-26 June 2025), the United Nations Framework Convention on Climate Change (UNFCCC) Secretariat hosted the annual intersessional Bonn Climate Change Conference in preparation for the 30th Conference of the Parties (COP) in Belém, Brazil. Often described as a “mini-COP,” this event—officially referred to as the Sessions of the UNFCCC Subsidiary Bodies (SBs)—convenes the Subsidiary Body for Implementation (SBI) and the Subsidiary Body for Scientific and Technological Advice (SBSTA).  This year’s session, known as SB62, marks the 62nd meeting of these bodies since their establishment in 1995 at the first COP. The SBs meet twice annually: first, in early summer in Bonn, and second, at year’s end for the COP. While less known compared to the highly mediatized COPs, the mid-year meeting serves as a critical point in international climate policymaking, as negotiations directly influence and set the groundwork for final decisions acted upon by parties at the COP. 

Key Actors Involved

The Subsidiary Body for Implementation (SBI)

The SBI is a permanent subsidiary body that advises the governing bodies on the progress of decision implementation. The SBI covers issues of finance, capacity-building, gender and climate change, and more. Centrally, they facilitate negotiations on financial and technical support to developing country parties.

The Subsidiary Body for Scientific and Technological Advice (SBSTA)

The SBSTA, the second permanent subsidiary body, advises the governing bodies on issues of scientific knowledge, serving as the bridge between IPCC scientific advisors and COP party delegations. In addition to other items, the SBSTA facilitated negotiations of Article 6 of the Paris Agreement (particularly relating to carbon markets) and technical reviews of national greenhouse gas inventories.

Both permanent bodies adopt draft conclusions that may inform or be forwarded to the COPs for further consideration. These negotiations are carried out by official delegations, primarily composed of government representatives and technical experts. It is common for the incoming COP presidency to send a larger delegation to build relationships, observe progress, and shape the COP’s level of ambition. For example, Brazil —host of COP30 in November 2025 — had the largest delegation this year, with 173 provisional attendees.1 Joining party delegates are observers, which include other UN agencies, intergovernmental and non-governmental organizations, research institutions, industry representatives, and other stakeholders, including Indigenous leaders, youth representatives, and more. Media members are also present to report on the outcomes of negotiations, however, they are not allowed in closed negotiation meetings. 

Main Objectives for SB Meetings

In Bonn, parties to the UNFCCC engage in negotiations across multiple workstreams (thematic areas under negotiation such as finance, adaptation, Article 6, and transparency) aimed at advancing the implementation of decisions adopted at previous COPs. These workstreams focus on refining draft texts related to UNFCCC bodies, institutional arrangements, and implementation mechanisms. The outputs of these discussions are consolidated into draft conclusions, which are submitted to the plenary sessions of the Subsidiary Bodies (SBSTA and SBI) for adoption. Once adopted, these conclusions become non-binding outcomes that may serve as technical guidance, inputs to negotiations, or recommendations for consideration at the next COP.

Setting the Stage for SB62

Leading up to SB62, André Aranha Corrêa do Lago, Brazil’s designated COP30 President, presented a third letter to the international community, focusing on the meetings in Bonn. The presidency emphasized three guiding and interconnected priorities: 2

  • To reinforce multilateralism and the climate change regime under the UNFCCC
  • To connect the climate regime to people’s real lives
  • To accelerate the implementation of the Paris Agreement by stimulating action and structural adjustments across all institutions that can contribute to it 

Emphasizing the importance of inclusiveness and transparency, the Presidency called for restoring trust and strengthening processes, stating that the “credibility of multilateral processes is in the hands of negotiators in Bonn.” 3

Behind the Scenes at SB62

Things got off to a slow start, as negotiators took nearly two days to adopt the meeting agendas. Disagreements—primarily around the inclusion of a discussion on developed countries’ finance obligations under Article 9.1 of the Paris Agreement—highlighted deep divides that would resurface throughout the session. While the delay was eventually resolved through compromise, it set a contentious tone for the rest of the talks and reinforced growing frustration over procedural inefficiencies and stalled ambition. 

Throughout the two weeks, progress was mixed. Adaptation was high on the agenda, particularly in terms of refining the list of global indicators under the Global Goal for Adaptation (GGA). A last-minute agreement allowed negotiations to move forward, with new guidance that included indicators for access to adaptation finance—a win for developing countries.4 There was also modest movement on transitioning the Adaptation Fund to serve exclusively under the Paris Agreement, and some procedural clarity around loss and damage reporting. However, on several items, including technology implementation and the mitigation work program, parties remained divided, and final decisions were deferred to COP30.

Finance remained one of the most divisive themes. Although a new collective quantified goal (NCQG) was adopted in Baku last year,5 dissatisfaction—especially from developing countries—was evident. The issue re-emerged across multiple agenda items, from adaptation indicators to the Global Stocktake and just transition discussions. The provision of predictable, adequate finance —and who bears responsibility—continues to cloud a number of different negotiations, confirming that climate finance is not just a standalone topic but an underlying current influencing many workstreams.

Negotiations on science likewise remained contentious. While parties ultimately agreed to “take note” of key climate science reports from the World Meteorological Organization, 6 some countries blocked the addition of “take note with concern,” limiting the outcome to a neutral acknowledgment of current warming estimates between 1.34°C and 1.41°C. Several delegations expressed frustration that even mentioning any reference to the 1.5°C limit remains politically sensitive for some parties like Saudi Arabia. Meanwhile, discussions on the technology implementation program remained inconclusive, with deep divisions over its role in advancing the Global Stocktake, particularly in relation to energy transition pathways.7

Ultimately, SB62 functioned less as a point of resolution and more as a staging ground for COP30 in Belém, Brazil, where many of the draft texts and negotiation tracks will carry forward. With most outcomes still provisional and riddled with caveats, the pressure is mounting. 

Looking Ahead: The Road to Belém

As the world looks ahead to November, key issues to watch include the operationalization of the new climate finance goal (NCQG) of US$300 billion and the “Baku to Belém Roadmap to US$1.3 trillion”, final guidance on Article 6 carbon markets, and whether progress on adaptation—particularly indicators and support—can move from technical debate to real-world implementation. Most crucially, countries were to submit updated Nationally Determined Contributions (NDCs)—their official climate action plans under the Paris Agreement—for the period up to 2035. These updates are expected to reflect alignment with the 1.5°C goal and respond to the findings of the Global Stocktake. Yet urgency continues to build amid slow progress: nearly 95% of countries missed the UN’s informal February deadline to submit their new pledges, raising concerns about political momentum and transparency.8

The year 2025 marks two major milestones in the climate process: 30 years since the first COP and a decade since the adoption of the Paris Agreement—lending symbolic weight and heightened expectations to Brazil’s presidency. While Brazil has sought to present itself as a unifying force, cracks are already showing. With concerns surrounding the lack of transparency and inclusiveness of its proposed Circle of Finance Ministers,9 tasked with supporting the development of the new climate finance roadmap, coupled with concerns about Belém’s logistical capacity, questions have been raised about its ability to deliver a truly inclusive and effective COP.

In a year rich in symbolism, the credibility of the multilateral system may rest as much on process and participation as on policy outcomes. The notable absence of a formal U.S. delegation—following the Trump administration’s withdrawal from the Paris Agreement and its freeze on international climate finance—has further highlighted the fragility of global climate leadership. Combined with growing geopolitical tensions and declining trust in multilateralism, the stakes for COP30 could not be higher.

  1. UNFCCC. (2024). Presidency summary of the first Global Stocktake. https://unfccc.int/documents/647692 ↩︎
  2. COP30 Brazilian Presidency. (2025). Third letter from the presidency. https://cop30.br/en/brazilian-presidency/letters-from-the-presidency/third-letter-from-the-presidency ↩︎
  3. Ibid. ↩︎
  4. Earth Negotiations Bulletin. (2025, June 28). Summary of the Bonn Climate Change Conference – June 2025 (Vol. 12, No. 876). International Institute for Sustainable Development (IISD). https://enb.iisd.org/sites/default/files/2025-06/enb12876e.pdf ↩︎
  5. European Chair for Sustainable Development and Climate Transition, Sciences Po. (2025, February 14). Assessing COP29: Did the ‘Finance COP’ meet its lofty goals? https://www.sciencespo.fr/psia/chair-sustainable-development/2025/02/14/assessing-cop29-did-the-finance-cop-meet-its-lofty-goals/ ↩︎
  6. Including the State of the Global Climate 2024 and the Global Annual to Decadal Climate Update 2025–2029 ↩︎
  7. Earth Negotiations Bulletin. (2025, June 28). Summary of the Bonn Climate Change Conference – June 2025 (Vol. 12, No. 876). International Institute for Sustainable Development (IISD). https://enb.iisd.org/sites/default/files/2025-06/enb12876e.pdf ↩︎
  8. Carbon Brief. (2025, June 26). Analysis: 95% of countries miss UN deadline to submit 2035 climate pledges. https://www.carbonbrief.org/analysis-95-of-countries-miss-un-deadline-to-submit-2035-climate-pledges/ ↩︎
  9. Climate Change News. (2025, June 23). UN expects climate finance roadmap to offer ‘clear next steps’. https://www.climatechangenews.com/2025/06/23/un-expects-climate-finance-roadmap-to-offer-clear-next-steps ↩︎