Activists gathered near the venue, wearing oversized masks of global leaders lounging in hammocks, a visual reminder that progress remains slow.
They argue that decades of climate summits have produced pledges rather than transformation, while temperatures climb and the Amazon weakens.
Environmental defenders, particularly Indigenous communities, continue to face threats and exclusion.
Many describe this year as the moment for implementation rather than speeches, urging leaders to act with real resolve.
The contrast between Brazil's climate ambitions and ongoing fossil fuel expansions adds tension, raising questions about credibility and responsibility.