On Sunday, Mexicans chose Claudia Sheinbaum as their new leader – blazing a trail not just by electing the country’s first female president but also by putting a climate scientist at the helm of a major nation.
Sheinbaum, an energy engineer who worked unpaid on two major reports issued by the Intergovernmental Panel on Climate Change (IPCC), will take control of the world’s 14th biggest economy on December 1, for a term due to last until 2030.
While IPCC climate scientists have been appointed as environment ministers in countries like Chile and Egypt, Climate Home was unable to identify any who have served as a national leader.
As Sheinbaum courted votes across the country of 127 million grappling with a drought, heatwave and smog, she promised to invest nearly $14 billion in clean energy and boost electric buses and trains.
“We have to speed up the promotion of renewable energies,” she told a group of Mexican businessmen in April. “We are working on the national energy plan not only through 2030, but to 2050”.
Deep scepticism
But some fellow Mexican climate scientists and political analysts told Climate Home they were sceptical about whether she will deliver on her green promises.
They criticised her record as mayor of Mexico City, a position she held from 2018 to 2023, and said her climate ambition would be held back by her close ties to current pro-fossil fuel President Andrés Manuel López Obrador (known as AMLO) and her ideological aversion to private-sector energy.
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Political risk analyst Carlos Ramirez, a partner at Integralia Consultants, told Climate Home that “there is no question that her commitment to climate change is real”, adding “that is a welcome shift from what we have seen so far [under the current government]”.
But, he said, “there will be López Obrador ghosts haunting her – his legacy will mean that she cannot move much from what we are seeing now, and the people who surround him will be watching her closely.”
If she did opt for bigger green changes, “she would have to pay a political price for that,” he noted. “So far she has not given any evidence that she will do so.”
Emissions expert
Sheinbaum grew up in Mexico City with scientists for parents. She signed up to study physics herself, earning undergraduate and masters degrees at the National Autonomous University of Mexico (UNAM).
In the early 1990s, she spent four years at the Lawrence Berkeley National Laboratory in California, doing a PhD on energy emissions and environmental problems in Mexico City’s transport sector before joining UNAM’s staff.
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Following a stint as the environment secretary of then Mexico City Mayor López Obrador, she returned to UNAM and helped write the emissions reduction sections of the flagship IPCC assessment reports in 2007 and 2014. Her research on Mexican manufacturing and cement emissions was cited and – like all IPCC authors – she worked long hours unpaid.
Mexico City Mayor
Sheinbaum then went back into politics with López Obrador’s new left-wing party MORENA and was selected as its candidate for mayor of Mexico City in 2018, a position she held until she resigned last year in order to run for the national presidency.
As mayor, she promoted solar power. But UNAM climate scientist Ruth Cerezo-Mota said she had seen no sign of Sheinbaum attempting to solve the city’s serious air pollution problem.
Another UNAM climate scientist, Xochitl Cruz Núñez, who worked with Sheinbaum on the IPCC’s fifth assessment report, told Climate Home that Sheinbaum’s climate work as mayor was “minimal”.
Greenpeace activists protest with mariachi musicians and a cake with bicycle lanes, outside Mayor Sheinbaum’s office in March 14, 2019. (REUTERS/Henry Romero)
Cruz Núñez criticised the city’s diesel-powered bus system, water scarcity and increased urbanisation under Sheinbaum’s leadership, saying it had caused “uncontrolled” construction in surrounding conservation areas.
AMLO’s legacy
Mexico previously enjoyed a reputation as a front-runner on climate action, passing one of the developing world’s earliest climate change laws in 2012. But some of that progress was reversed during López Obrador’s presidency.
The outgoing president dismantled climate policies and institutions and promoted energy sovereignty through domestic fossil fuel production, putting power back into the hands of state-owned companies: electricity utility CFE and oil and gas giant PEMEX.
His government invested billions of dollars into oil and gas infrastructure, and blocked private investment into renewables. Today, Mexico is one of only two G20 countries without a net zero emissions target and has watered down its 2030 emissions reduction goal.
Sheinbaum became MORENA’s candidate for the presidency largely because of López Obrador’s support for her, winning the national election on Sunday partly thanks to his track record as the country’s most popular modern president.
Lopez Obrador and Sheinbaum before a manifesto presentation on November 20, 2017. (REUTERS/Henry Romero)
Political analyst Ramirez said Sheinbaum’s political alignment with López Obrador hinders the chances of her pursuing more ambitious climate action.
“Sheinbaum is speaking loudly about bringing renewables back into the system but at the same time – and here is where the problems begin – she wants to give continuity to the energy policy of López Obrador,” he said.
“She has a strong ideological view that [state-owned] CFE and PEMEX should lead the energy transition,” he added. “This is a contradiction. I think it will be a very slow process and eventually fail.”
Cruz Núñez noted that Sheinbaum intends to maintain state stewardship over oil and electricity, while mobilising public resources for renewables, but questioned whether this alone could work. “My opinion is that private investment is required if renewable energy is to be introduced at the level needed for Mexico to fulfill its promises under the Paris Agreement,” she added.
Despite her alliance with AMLO, Sheinbaum has disagreed with him in the past. During the Covid-19 pandemic, for example, she promoted mask-wearing, testing and vaccinations in Mexico City while the president played down the risks.
Cruz Núñez expressed hope that, having won the election, Sheinbaum will take advantage of her new independence from López Obrador to establish a clear programme for cutting Mexico’s emissions and adapting to climate change.
“I believe she knows enough about climate change and the need to solve it,” she added.
(Reporting by Daisy Clague, editing by Joe Lo and Megan Rowling)
The post Mexico elects a climate scientist as president – but will politics temper her green ambition? appeared first on Climate Home News.
Mexico elects a climate scientist as president – but will politics temper her green ambition?
For the first time, new-energy vehicles (NEVs) made up 67% of new car sales in China in September, according to the latest data from the China Passenger Car Association (CPCA).
The figures show that NEVs, which include battery electric cars and plug-in hybrids, captured a record share of sales, even though fewer were sold than last year.
This is because sales of combustion-engine cars are falling steeply, a trend that the CPCA has attributed to rising petrol prices following the start of the Hormuz crisis.
Indeed, sales of fuel-only cars were down 31% year-on-year in the first nine months of 2026, with plug-in hybrid sales down 26% – whereas battery EV sales were only down 4%.
One analyst tells Carbon Brief that China’s rapidly growing EV fleet has offset demand for 143m barrels of oil since the start of the Hormuz crisis.
Another says that the crisis is “reinforcing China’s electrification of road transport”.
Meanwhile, amid slowing domestic sales, Chinese carmakers’ exports of NEVs more than doubled [in 2026 to date / in September] from a year earlier.
NEV record
A record two out of every three cars sold in September in China were NEVs, according to CPCA data, as shown in the figure below.
(NEVs predominantly include battery electric vehicles – BEVs – and plug-in hybrids – PHEVs. BEVs only run on electricity, whereas PHEVs also have a combustion engine.)
This marks a rapid rise for NEVs from just 6% of new car sales in 2020 up to 58% in 2026 to date – and a record 67% in the month of September.
This year, NEVs’ share of sales has also bounced back from a low of 39% in January, after the full purchase tax exemption that had been in place for more than a decade came to an end in December 2025.
The gain in NEV share in 2026 has come amid a slowdown across the wider domestic passenger-car market, which has hit sales of combustion-engine vehicles particularly hard.
This September, passenger-car retail sales across all categories declined, with overall sales volumes falling 28% year-on-year.
The contraction was led by combustion-engine vehicles, which saw sales fall 43% year-on-year in September and 31% in 2026 to date.
However, sales of PHEVs also fell by 36% year-on-year in September and by 26% in 2026 to date. By comparison, BEVs performed better, although sales still declined 8.5% from a year earlier in September and 4% in 2026 to date.
As a result, NEV sales overall fell by 17% in September and 13% in 2026 to date.
While the market changes in 2026 to date were particularly dramatic, they reflect a broad continuation of trends seen over the past decade.
Indeed, sales of combustion-engine cars in China peaked in 2017 and they have been declining ever since, shown in the figure below.
Impact of Hormuz
Part of the reason for the advance of NEVs in 2026, said Chinese technology news outlet OFweek, was petrol cars “giving up market share” as they were outperformed by electric alternatives.
Cui Dongshu, secretary-general of the CPCA, cited higher petrol prices as an explanation for September’s weak combustion-car sales, in comments to financial news outlet National Business Daily.
Imports of oil into China in January-September have fallen 15% compared to 2025, equivalent to 470m barrels, as ongoing conflict tightened supply and drove up prices.
China’s passenger-car NEV fleet has displaced 143m barrels of oil so far during the strait of Hormuz crisis, Euan Graham, senior energy analyst at thinktank Ember, tells Carbon Brief.
EVs “accounted for 12% of the decrease in China’s oil use post-Hormuz”, according to an estimate provided to thinktank the Brookings Institute by an unnamed analyst.
Erica Downs, a senior research scholar at Columbia University’s Center on Global Energy Policy, tells Carbon Brief that the strait of Hormuz crisis and higher oil prices are “reinforcing China’s electrification of road transport”.
She says the “world’s largest oil supply disruption” vindicates China’s early bet on EVs, which was partly driven by concerns about oil-supply security.
NEV demand down
Nevertheless, NEV sales have fallen year-on-year, albeit at a slower rate than overall car sales. The growth in NEV market share has also been decelerating.
Zhang Yichao, a partner at consulting firm AlixPartners, tells Carbon Brief that NEVs benefit from government trade-in policies and a “strong pipeline” of new models, particularly those involving innovation.
He says these factors help explain why NEVs sales have fallen at a slower rate to their combustion-car counterparts.
Cui told the state-run China National Radio that the fall for NEVs and for cars overall in September 2026, is also due to a high baseline of sales from the same month in 2025, as well as changes to trade-in policies and disruptions from the holiday period.
Other factors, says consulting firm Wood Mackenzie, are the weakened demand due to “demand pull-forward” in 2025 caused by the end of subsidies, as well as “tighter financing conditions”.
Zhang tells Carbon Brief he does not “see much more room ahead” for furthe