Carbon Debt and the BRICS View on Fossil Fuels: Why Historical Emissions Matter at COP31
With about a month left for COP31 (the 31st UN climate summit, to be held in Antalya, Türkiye, from 9 to 20 November 2026), the idea of "carbon debt" is back at the centre of climate talks.
Carbon debt means the large amount of carbon dioxide (CO2) that rich, developed countries put into the air while they industrialised over the last 150 years or more. Developing countries argue that this past pollution is a "debt" these countries owe to the rest of the world.
Experts cited figures on cumulative (total, added-up) CO2 emissions between 1890 and 2019: the United States about 400 gigatonnes (Gt), the European Union about 348 Gt, China about 220 Gt and India about 53 Gt. India's total is only about one-ninth of the US total.
The BRICS New Delhi Declaration, adopted at the 18th BRICS Summit in New Delhi (12–13 September 2026), said fossil fuels "will still play an important role in the world's energy mix", especially for emerging and developing economies. It also stressed the need for "just, orderly, equitable and inclusive energy transitions".
Climate experts linked this position to the principle of Common but Differentiated Responsibilities (CBDR-RC). Under it, developed countries must cut emissions first and give developing countries money (climate finance), help with adaptation and clean technology.
Some experts also cautioned that carbon debt should not become a licence for unlimited fossil fuel use by developing countries either, since every country suffers from a warming planet.
Carbon Budget: Historical Emissions and the Idea of Carbon Debt
A carbon budget is the total amount of carbon dioxide (CO2) that all humans together can still release into the air if we want to keep global warming below a chosen limit, such as 1.5°C or 2°C. Think of it like a fixed family budget for a month: once the money is spent, it is gone. Every tonne of CO2 that any country releases is spent from the same shared budget. The idea of carbon debt follows from this: some countries have already spent far more than their fair share of the budget, so they are said to "owe" the others.
Ahead of COP31, experts used the carbon budget idea to explain why BRICS countries say fossil fuels will still have a role in their energy mix. Their argument is that rich countries have already used most of the shared budget, so the burden to cut fast and to pay for the transition must fall on them first.
Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC)
CBDR-RC is a basic principle of world climate law. It says all countries share the duty to protect the climate, but rich countries must do more because they polluted more in the past and have more money and technology. It first appeared in Principle 7 of the 1992 Rio Declaration and was written into Article 3.1 of the UNFCCC. It is the legal and moral base on which developing countries build the idea of carbon debt.
Experts said the BRICS stance on fossil fuels rests on CBDR-RC. In their view, developed countries must cut first and fund the shift, while developing countries move to clean energy at a pace that does not stop their growth.
UNFCCC and the Conference of the Parties (COP)
The United Nations Framework Convention on Climate Change (UNFCCC) is the main world treaty on climate change, agreed in 1992. The Conference of the Parties (COP) is its yearly meeting of all member countries and its top decision-making body. Big climate deals like the Kyoto Protocol (COP3, 1997) and the Paris Agreement (COP21, 2015) were agreed at COPs. Each COP has a host country and a president who guides the talks.
COP31 is where the debate over fossil fuels and carbon debt will play out. The BRICS position that fossil fuels still have a role will meet demands from other groups for a faster move away from them, which builds on the COP28 language.
- COP31: Antalya, Türkiye, 9–20 November 2026; Australia is President of Negotiations
- Cumulative CO2 emissions 1890–2019 (as cited by experts): US about 400 Gt, EU about 348 Gt, China about 220 Gt, India about 53 Gt
- 18th BRICS Summit: New Delhi, 12–13 September 2026; New Delhi Declaration adopted on 12 September 2026
- BRICS Declaration: fossil fuels "will still play an important role" in the energy mix; calls for "just, orderly, equitable and inclusive energy transitions"
- Remaining 1.5°C carbon budget (Global Carbon Budget 2025): about 170 Gt CO2 from start of 2026, about 4 years at current rates
- Global CO2 emissions: about 42 Gt per year
- India's share of historical emissions: about 3–4%; share of world population: about 17%
- India net zero target: 2070; NDC 3.0 (April 2026): 47% emissions intensity cut by 2035 from 2005 levels
- CBDR-RC: Rio Principle 7 (1992), UNFCCC Article 3.1, Paris Agreement Article 2.2
- COP29 NCQG: $300 billion a year by 2035