High-stakes negotiations at COP29 have hit a major roadblock. Developing nations stormed out of talks, rejecting an offer of $250 billion annually by 2035 to tackle climate change. The dramatic exit comes amid accusations that fossil fuel states and wealthy nations are prioritizing politics over the survival of vulnerable countries.

COPs have been getting progressively longer; the excellent team at Carbon Brief extrapolated the trend line, which suggests COP29 will end in the small hours of Sunday morning. Even that may be optimistic.

Negotiations at Cop29 in Baku, Azerbaijan were scheduled to finish on Friday evening but a final deal on climate finance remains elusive.