Net-zero emissions pledges and a commitment by leaders at the COP26 climate conference to cut methane, if enforced, could enable the world to limit global warming to below 2 degrees Celsius, the International Energy Agency said on Thursday.
"New IEA analysis shows that fully achieving all net-zero pledges to date & the Global Methane Pledge by those who signed it would limit global warming to 1.8C," IEA chief Fatih Birol wrote on Twitter.
The comments, made a few days after the pledges were announced at the Glasgow summit, drew warnings of caution as the IEA's new assessment relies on countries and companies following through with their promises for years if not decades to come.
Nicholas Stern, who produced a landmark 2006 report on the economics of climate change, said COP26 was showing promise but told Reuters: "All the estimates have their own uncertainties, but also it's the whole path that matters. You can't estimate a temperature just from a point."
Taking note of the IEA report, he urged delegates at the UN conference to remember that, even as temperature projections improve, "we really mustn't lose sight of the 1.5C".
A global deal agreed in Paris in 2015 set the goal of preventing global warming above 1.5C - the limit that scientists say could prevent the most catastrophic and irreversible impacts of climate change.
To meet it, the IEA has said the world needs to eliminate new fossil fuel investments.
During a panel discussion in Glasgow on Wednesday, Birol said he asked his colleagues at the IEA to run climate models again, asking "What would it mean if all the pledges announced ... were to be implemented?"
And his team reported to him Tuesday night the result, which was "extremely encouraging," he said.
He acknowledged that some net-zero pledges were "a bit longer-term horizons". Big-emitter India on Monday announced it would aim to reach net zero only by 2070 years after scientists say is needed.
Nevertheless, with the potential for rapid impact from the promised drawdown of methane emissions, Birol said "we would have a temperature increase trajectory that is 1.8 degrees Celsius."
A UN report released days before the Glasgow talks said pledges to cut climate-warming emissions put the planet on course for a 2.7C temperature rise this century.
Non-governmental organisations said they could not confirm the IEA assessment, but were encouraged by the number of new pledges.
"I can't verify those numbers," said Jules Kortenhorst, CEO of RMI, a non-profit working on the global energy transition. Though, "the impact of the methane pledge is really enormous."
Likewise, the rapid series of financial and company commitments has been "very, very powerful, and is completely unrivalled" by action committed at other COPs held over the last 15 years, Kortenhorst said.
Change of course at iea
Birol's comments don't "detract from the urgent need to close down coal production in this decade, and thereafter oil and gas," said Mark Campanale, founder and executive chair of Carbon Tracker, a London-based non-profit think tank.
On Thursday, 77 countries pledged to phase out coal, the dirtiest of the fossil fuels. But China and India, both heavily reliant on coal-fired power, were conspicuously absent.
The Paris-based IEA, the world's top energy watchdog, was founded after the 1973 oil crisis to ensure developed countries had access to affordable and reliable energy.
The United States, one of the world's top fossil fuel producers and consumers, is among its top financial backers.
In May, the IEA departed from years of describing the status quo in the energy industry with a warning that no new fossil fuel projects beyond this year besides those already approved should be given the go-ahead if the world hoped to achieve net zero emissions by 2050.
The agency doubled down on the recommendation in its flagship annual World Energy Outlook last month, which aids countries and companies in making billions of dollars worth of investment decisions.
The report said clean energy investment needed to triple within the next decade if net-zero goals are to be reached by mid-century, and that the recovery from the pandemic had relied excessively on fossil fuels.
A study released Thursday showed that global carbon emissions have already rebounded nearly to pre-pandemic levels.