The world is on course for an “irrecoverable overshoot” of dangerous warming unless governments turn away from fossil fuels and accelerate emissions cuts, a new report warns.
The latest assessment from the Climate Action Tracker (CAT) initiative was released as countries gathered in Turkey for COP31, the United Nations climate talks. It says global efforts to tackle climate change have stalled for a fifth straight year.
There are signs of momentum in some areas. Clean electricity supplied all additional global power demand in 2025, while China and India expanded renewable energy at record speed. Electric vehicle sales also reached new highs, and deforestation in the Amazon dropped sharply.
Yet the report says the shift away from fossil fuels – the main source of greenhouse gas emissions when burned for transport, heating, electricity and industry – remains far too slow.
Based on the climate policies and clean-energy measures governments have adopted so far, the world is headed for 2.7C of warming by 2100. That is slightly higher than the 2.6C forecast issued last year and matches projections made from 2021 to 2024.
Even if governments fulfilled their 2030 and 2035 emissions-cutting targets under the Paris Agreement – the international treaty designed to limit warming to 1.5C and avoid the most dangerous effects of climate change – warming would still reach 2.6C, unchanged from last year.
In the most optimistic scenario, with countries delivering every pledge and target aimed at reaching net zero emissions, global temperatures would rise by 1.9C by the end of the century.
The 1.5C Paris target is expected to be breached within the next few years. Experts say governments must still act to reduce both the scale and length of that overshoot, with the aim of bringing temperatures back below 1.5C above pre-industrial levels by 2100.
A sharp fall in Amazon deforestation is among the report’s positive findings
Bill Hare, chief executive of CAT partner organisation Climate Analytics, said governments faced a stark choice between continuing to back fossil fuels and embracing increasingly affordable alternatives.
“The stark choice for governments is to either continue to support the fossil fuel industry, which would consign humanity to insurmountable economic damages, rising mortality from heat and climate-driven diseases, and disasters that they are unable to adapt to, or pivot to the solutions which are available and cheaper than ever,” he said.
“The imminence of breaching 1.5C cannot be an excuse to open the door to defeatism – the focus has to be on accelerating action to limit the magnitude and duration of overshoot.
“Every increment of warming above 1.5C means even more significant consequences across climate, nature and human systems.”
Scientists say a breach of 1.5C would intensify extreme weather, including deadly heatwaves, floods, storms and droughts. It would also drive sea-level rise and increase the risk of catastrophic, irreversible damage to natural systems such as coral reefs and rainforests.
An analysis released earlier this week by the Global Carbon Budget initiative pointed to a modest 0.4% fall in fossil-fuel carbon emissions this year, attributed to the rapid expansion of solar and wind power and the Iran conflict.
Dr Niklas Hohne, of CAT partner organisation NewClimate Institute, said the disruption surrounding the Strait of Hormuz had highlighted the risks of relying on fossil fuels in an unstable geopolitical environment.
“With the closure of the Strait of Hormuz exposing our vulnerability to geopolitical shocks, the case for renewables and electrification has never been stronger,” he said.
“It does appear that global emissions could be on the verge of a peak and a much faster decline than we had previously thought.”
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But Sarah Heck, a policy analyst at Climate Analytics and the report’s lead author, said governments were “simply not moving fast enough to adopt the policies that would enable us to escape from the emerging overshoot trap”.
“Worse, several are taking their foot off the accelerator and slowing their climate action – or in cases such as the USA, Canada and New Zealand – rolling it back at a staggering level,” she added.
As a result, CAT said long-term warming is expected to pass the 1.5C threshold at around 2030.
To keep any overshoot of 1.5C as limited as possible, emissions cuts would need to accelerate from roughly 4% a year through 2030 to 7% annually during the first half of the 2030s, followed by reductions of 9% a year between 2035 and 2050.
That would exceed the 7% fall in fossil-fuel carbon emissions recorded in 2020, when Covid-19 lockdowns brought economic activity around the world to a halt.
