Iran War's Oil Shock Helped Push Global Fossil Fuel Emissions Down in 2026 — Scientists Warn It Won't Last

For only the third time this century, global carbon dioxide emissions from fossil fuels are falling — and the Iran war is a significant reason why. A major international scientific assessment released Monday at the COP31 climate summit in Antalya, Turkey, projects that fossil fuel CO₂ emissions will drop 0.4% in 2026, reaching 38.2 billion tonnes, as soaring oil prices triggered by the conflict and the closure of the Strait of Hormuz pushed drivers and industries away from petroleum products.

The finding, published in the journal Earth System Science Data by the Global Carbon Budget — an annual assessment drawing on more than 140 scientists from universities and research institutions worldwide — marks the first annual decline in fossil fuel emissions since the COVID-19 pandemic paralysed global transport and trade in 2020. The previous drop before that was during the 2009 global recession.

It's downwards which sounds good, but this is largely driven by the war in Iran, what's happened in the Strait of Hormuz. So in a way, a little bit of good news, but for the wrong reasons.— Glen Peters, scientist at the CICERO Center for International Climate Research, Norway

Oil emissions are projected to fall nearly 2% — the sharpest single-fuel drop — while natural gas emissions are down 0.3%. Coal use, however, is up 0.6%, driven largely by India, whose overall fossil fuel emissions rose 4.4% this year. Peters argued that the sudden, sharp nature of the oil drop points to a war-driven disruption rather than a lasting energy transition. Renewables-led change would produce a gradual peak followed by a slow decline, he explained, but instead the data show oil emissions climbing and then abruptly plunging 2%, Peters told The Independent.

The expansion of solar, wind and electric vehicles also contributed. According to the report, solar and wind power and electric vehicles together accounted for two-thirds of the growth in global energy demand this year. But researchers are careful to separate the two forces driving the decline, because only one of them is durable.

A decline in fossil CO2 emissions is encouraging, but a reduction driven partly by geopolitical shocks is not a sustainable climate solution. The long-term answer remains the rapid deployment of clean energy technologies.— Pierre Friedlingstein, director of the Global Carbon Budget Office, University of Exeter

The concern about a rebound is grounded in recent history. After both the 2009 financial crisis and the COVID-19 pandemic, emissions recovered and surpassed previous levels once economies restabilised. Corinne Le Quere, a climate change science professor at the University of East Anglia, told the Straits Times that a comparable rebound is likely once "the oil tensions go away."

Critically, even the fossil fuel decline is being outweighed elsewhere. When land-use emissions — from deforestation, peat fires and conversion of wild land to agriculture — are included, total global CO₂ emissions are projected to rise slightly, from 42.8 billion tonnes in 2025 to 43.3 billion tonnes in 2026. Researchers attributed the rise in land-use emissions partly to peat fires and forest degradation in South-east Asia, linked to an exceptionally strong El Niño pattern this year.

China, the world's largest emitter, is expected to reduce its carbon output by close to 1% in 2026, mostly because of a 5% drop in oil use following the Iran war. Some experts see structural reasons for optimism about China beyond the oil shock — the country has been rapidly scaling solar, wind, electric vehicles and supporting infrastructure — but scientists say it is too early to confirm whether China's emissions have permanently peaked. US emissions are projected to fall about 1.3%, largely from reduced coal use, despite the Trump administration's push to expand fossil fuels. Europe and Japan also showed roughly 1% declines, which Peters attributed to the oil shock.

A drop in emissions in one year is not a peak, unless it is driven by structural change. Accelerated deployment of solar, wind, batteries and electric vehicles are pushing emissions down in dozens of countries, and slowing emissions growth in many more, but the changes are not sufficient to lock in a peak in global emissions.— Glen Peters, research professor, Cicero Centre for International Climate Research

The report's most urgent number is the world's remaining 'carbon budget' — the total amount of CO₂ that can still be emitted before global warming is likely to permanently exceed 1.5°C above pre-industrial levels. That budget now stands at approximately 150 billion tonnes. The researchers determined that, if emissions continue at their present pace, that budget will run out in under four years. Sea and air temperatures have been pushed even higher by El Niño conditions, compounding the fact that global average temperatures have already been above the 1.5°C threshold for more than two years.

The picture from the Global Carbon Budget is a flatline, not a decline — a projected fall of just 0.4% in 2026, a figure that is unfortunately statistically indistinguishable from zero. We are heading towards a sustained breach of 1.5C by around 2030.— Bill Hare, chief executive of Climate Analytics

COP31 opened to these findings, with the gathering in Antalya drawing more than 90 heads of state and government along with high-level representatives from more than 190 countries for two weeks of climate negotiations. Hare noted that several major economies — including Canada, the US and New Zealand — are rolling back climate policies, while Australia, a co-president of COP31, continues to develop large coal and gas projects. Regarding the Turkish and Australian leadership of the summit, Hare said there is "little sign yet" that they plan to advance the commitment to transition away from fossil fuels that was made three years ago.

We shouldn't lose sight of the bigger picture. The world is still pumping more than a thousand metric tons of carbon dioxide into the atmosphere every second.— Mohamed Adow, director of Power Shift Africa

Why it matters — With the world's remaining carbon budget likely to run out in under four years, a one-off, war-driven dip in fossil fuel emissions — easily reversed when oil prices normalise — does little to change the trajectory toward a sustained breach of the 1.5°C warming threshold.

Sources differ on Whether China's emissions have permanently peaked: Too early to say — the drop may be a one-off driven by the oil shock, and China could rebound next year. (theguardian.com) vs China is building a fundamental economic transformation around solar, wind and EVs that is steadily reducing fossil fuel dependence — its emissions may have peaked. (independent.co.uk)

Reported by livescience.com, theguardian.com, telegraph.co.uk, independent.co.uk, straitstimes.com