Every year, the U.N. climate conference generates hundreds of headlines about global efforts to save the planet from climate catastrophe. This year’s summit begins Monday in the Brazilian rainforest city of Belém.
But what actually happens at these annual gatherings? Here’s what you need to know:
The annual conference is known as a COP, short for Conference of the Parties that signed the 1992 U.N. climate treaty. The treaty, called the U.N. Framework Convention on Climate Change (UNFCCC), committed countries to work together to fight climate change—a problem they agreed all nations face and can best tackle collectively.
The treaty also established the principle of “common but differentiated responsibilities,” meaning wealthier nations responsible for most of the planet-warming emissions bear greater responsibility for addressing the crisis.
The rotating presidency—currently held by Brazil—sets the summit agenda and spends the year rallying governments toward shared goals and action. It then hosts the two-week summit, drawing global attention to climate issues while giving world leaders a chance to exchange ideas and hold one another accountable.
Over the years, the summits have become major hubs for geopolitical and financial discussions, embodying the idea of a “global village” that brings together countries, civil society groups, businesses and financiers.
For many, this year’s 30th climate summit marks a full-circle moment.
Brazil hosted the 1992 Rio Earth Summit where the UNFCCC treaty was signed. Now, 33 years later, the country says it wants to return to the treaty’s original spirit—recognizing the world’s most vulnerable communities, including Indigenous groups, some of whom will join the talks.
Brazil has urged countries to focus on fulfilling past commitments—such as the COP28 pledge to phase out fossil fuel use—rather than making new promises. COP30 is also the first to formally acknowledge that the world has fallen short of its goal to limit warming to 1.5 degrees Celsius.
Hosting the summit in Belém, at the gateway to the Amazon, Brazil aims to highlight the global importance of forests that remain under threat from logging, mining, agriculture and fossil fuel extraction.
Most national governments send delegations, often aligning with others that share similar interests.
Prominent blocs include the Alliance of Small Island States, which faces an existential threat from rising seas, and the G77 + China coalition of developing nations.
Also influential are the Africa Group and the BASIC Group—Brazil, South Africa, India and China. The United States, which announced plans in January to withdraw from the Paris Agreement, has stepped back from its previous leadership role. China, Brazil and others have moved to fill the gap.
The COP venue is typically a hive of activity, with campaigners promoting their causes while corporations lobby for policy changes and pursue business opportunities.
This year’s approach is unusual: many of the usual side events have been moved elsewhere. Financiers are meeting in São Paulo, while local leaders gathered in Rio de Janeiro. Those events, along with a meeting of world leaders in Belém, were held before the Nov. 10–21 COP30 to build momentum for the talks.
During the first week, negotiators outline priorities and gauge other countries’ positions. Themes begin to emerge as governments and companies announce new action plans and funding pledges.
In the second week, national ministers join the talks to hammer out final agreements, including legal and technical details.