Nearly 200 countries will gather next week for the U.N. climate summit, COP29. Reaching a consensus for a deal among so many can be difficult.
Here are some of the major players and negotiating blocs involved in the COP29 summit starting Nov. 11 in Baku, Azerbaijan.
CHINA
China produces the most energy from climate-warming fossil fuels and also from renewable energy sources. It accounts for about 30% of the world's annual carbon emissions, making China the biggest greenhouse gas polluter.
However, the country's emissions may have peaked following recent expansions in renewable energy, according to the Helsinki-based Centre for Research on Energy and Clean Air.
Although the world's second largest economy after the United States, China retains the developing country designation in U.N. climate negotiations that began in the 1990s.
As such, it says the United States and other industrialised countries should move first and fastest with climate action. Beijing also rejects calls for it to contribute to climate finance for developing countries.
China will send to COP29 a new diplomat for climate change as Liu Zhenmin, a former vice foreign minister has replaced long-time climate envoy Xie Zhenhua who retired.
UNITED STATES
The world's second largest emitter, and largest historic emitter, comes to COP29 following an election that will put Donald Trump back in power in 2025.
U.S. negotiators from the outgoing Biden Administration, led by White House senior adviser John Podesta, will represent the country at COP29.
But Trump's victory has reduced the chance of a strong deal on a new global finance target, or an agreement to increase the pool of countries that should contribute.
President-Elect Trump has promised to again pull out of the 2015 Paris Agreement and has labelled efforts to boost green energy a "scam".
Although the Biden Administration has provided hundreds of billions of dollars for climate change mitigation and adaptation through the Inflation Reduction Act, the U.S. has continued to break records as the world's biggest oil and gas producer during his presidency.
EUROPEAN UNION
The 27-country EU has not yet offered its position on some of the most divisive issues for COP29.
It has yet to say how big the new climate finance target should be, or how much should come directly from national budgets as opposed to multilateral lending institutions or private investment. It has demanded, however, that China and other fast-developing economies contribute.
The EU and its member states have contributed the most global climate finance to date, having more than doubled their offer over the last decade. In 2023, the EU and its member states contributed 28.6 billion euros ($30.8 billion USD) in climate finance from public sources.
UNITED KINGDOM
Britain's Labour Party government, elected in July, plans to emphasise its climate commitment at COP29, after Energy Minister Ed Miliband described Britain as being "back in the business of climate leadership".
The country, which hosted the COP26 summit in Glasgow in 2021, has promised to submit its next set of emissions-cutting pledges for 2035 at the Baku summit, three months before it is due in February.
Britain also has called for an ambitious finance goal, but it is unclear how much it could contribute from its debt-strained budget.
THE TROIKA
Calling themselves "the troika," the host countries of COP28, COP29 and COP30, last year said they were collaborating to ensure continuity in organising the annual U.N. climate talks.
All three countries have economies that rely on fossil fuels. The COP28's United Arab Emirates and COP30's Brazil are among the world's 10 biggest oil producers and COP29's Azerbaijan is a proponent of its natural gas industry.
'BASIC' COUNTRIES
As fast-developing and populous nations, Brazil, South Africa, India and China can have an outsized impact on the world's ability to tackle climate change.
Each country has asked for more climate financing through the concept of "common but differentiated responsibilities" - meaning rich countries that emitted the most historically should do more to address the problem.
OTHER NEGOTIATING BLOCS:
G77 + CHINA - This alliance of 77 developing countries and China also says rich countries have a bigger responsibility to cut CO2 than poorer nations.
AFRICAN GROUP OF NEGOTIATORS
African countries will be pushing at COP29 for more climate finance and getting the Paris Agreement's Article 6 on carbon market rules into force by early next year.
They remain concerned about the idling of the loss and damage fund following this year's flooding in East Africa and fatal heatwaves in the Sahel.
African countries plan to challenge a decision to place the fund's technical assistance body in Geneva, objecting to the high-cost city being chosen over recommendations for Nairobi.
The fund's headquarters will be in the Philippines, but the technical assistance body that provides support to countries faced with damages from climate-fuelled natural disasters will be in Switzerland.
ALLIANCE OF SMALL ISLAND STATES
A powerful group of countries disproportionately affected by climate impacts, notably sea level rise, the AOSIS bloc is focused on securing trillions of dollars in climate financing and advancing global efforts to phase out fossil fuel use.
LEAST DEVELOPED COUNTRY GROUP
This group's 45 nations are also highly vulnerable to climate change but have contributed little to it. They are asking for significant funding from developed countries, preferably in the form of grants. They also want more money to flow into the loss and damage fund.
HIGH AMBITION COALITION
Chaired by France, Costa Rica and Britain, this group pushes for more aggressive emissions-cutting targets and policies.
