Fossil fuel phaseout urged as reserves dwarf climate limit

Oil Change International released an analysis on October 29, ahead of the COP31 United Nations climate negotiations in Antalya, Türkiye, warning that fossil fuel extraction projects already operating or under construction hold enough oil, gas and coal to produce nearly seven times the carbon pollution the world can still emit while limiting warming to 1.5 degrees Celsius. The findings sharpen calls for a fossil fuel phaseout, and the group warns that fully extracting those reserves risks driving temperatures as high as 2 degrees Celsius.

Burning all of the fossil fuels in existing oil and gas fields and coal mines would release an estimated 897 billion tonnes of carbon dioxide, according to the updated Sky's Limit analysis. That figure stands against a remaining carbon budget of 130 billion tonnes for a 50% chance of holding warming to that limit, measured from the start of 2026. The gap between those figures is the central finding of the report: the fuels already developed, without any new project, far exceed the room left under the Paris Agreement goal.

Gas alone tells much of the story. Developed gas reserves would generate 150 billion tonnes of carbon dioxide if fully extracted, according to the analysis, exceeding the entire remaining budget even without counting a single additional barrel of oil or tonne of coal. Oil and gas fields together contain 3.5 times the remaining budget even if coal extraction stopped immediately, a point the authors use to argue against treating gas as a bridge that can replace coal without consequences. The report was published by Oil Change International, and the full analysis is available at the group's publications page.

Most developed reserves must stay in the ground

More than 85% of developed fossil fuel reserves must remain unextracted to stay within the remaining budget, according to the analysis, up from 60% in the group's 2023 assessment. The shift reflects a decade of continued approvals and investment in new extraction since the Paris Agreement, combined with a shrinking budget as emissions continued. Every fraction of warming prevented still matters, the authors argue, because overshoot brings irreversible harm, including extreme heat, flooding, food and water insecurity, and damage to ecosystems.

Committed emissions from oil, gas and coal extraction also exceed, by 30%, the remaining budget for a high probability of staying well below the higher threshold named in the Paris Agreement. Planning for the early shutdown of existing extraction sites is therefore critical, according to the analysis, to limit overshoot and preserve a chance of returning to the lower limit. The findings focus on carbon dioxide from extraction and combustion, and they do not fully account for additional warming from methane leakage, which means the picture could be worse than the carbon dioxide figures alone suggest.

The analysis updates peer-reviewed research on emissions committed by existing extraction projects, using recent oil and gas data from Rystad Energy and updated estimates of the remaining global carbon budget. Its authors stress that the scale of future damage is not fixed. Governments can still prevent the worst effects through policies that keep fossil fuels in the ground and accelerate a transition to renewable energy that is publicly funded and fair to workers and communities.

What COP31 is being asked to deliver

At COP31, governments are expected to discuss how to turn a commitment to transition away from fossil fuels into concrete national roadmaps, following the Santa Marta conference. The timing matters because, according to Oil Change International, recent United Nations Environment Programme reports warn that global temperatures are on course to exceed the lower limit at least temporarily in the coming years. Roadmaps that ignore production, the group argues, cannot credibly align with internationally agreed climate limits.

Oil Change International is calling for an immediate end to fossil fuel expansion, along with clear phaseout dates for production and use that match each country's historical responsibility and capacity. Those plans must protect workers and communities, guarantee the rights of people affected by extraction, and pair industrial policy and public funding with growth in non-fossil sectors. Kelly Trout, research director at Oil Change International, said the oversupply resulted from a decade of "reckless decisions" by governments and companies that kept approving and investing in new extraction despite knowing the consequences. She named the United States, Canada and Australia as the worst culprits for expanding oil and gas production since the Paris Agreement while claiming climate leadership, and said communities least responsible for the crisis are paying the highest price.

The pattern extends beyond those countries. The United States, Canada, Australia and Norway collectively increased oil and gas production by nearly 40 percent between 2015 and 2024, according to the group's earlier work, and also account for the majority of planned oil and gas expansion through to 2035. That record, the authors argue, is why wealthy countries must move earliest and fastest and pay a fair share toward a just transition worldwide, including through cooperation on debt, tax and trade rules that constrain many Global South countries from pursuing renewable energy.

Oil Change International plans to release a briefing on November 5 making the case for government-led roadmaps for prosperity beyond fossil fuels, including a toolkit of near-term policies to start that work. The negotiations in Antalya run from November 9 to November 20. For readers following the talks, GenZ NewZ climate emergency coverage will track how those roadmaps take shape, and whether pledges made in the negotiating halls translate into dates for ending expansion and shutting down existing fields early.