Montreal’s city administration is vowing to get tougher on fossil-fueled heating and fossil company divestment, but its climate plan has already led to the defection of one borough mayor who plans to advocate for faster, deeper carbon cuts as a private citizen.

Earlier this month, Mayor Valérie Plante promised a draft law next year that will ban oil heating systems in new buildings by 2030, but said a detailed plan to help residents make the “gradual transition to carbon neutrality” was still under discussion. “Plante said heating oil alone accounts for 28% of the residential sector’s greenhouse gas emissions and 14% of the commercial and institutional sector’s emissions” within the Montreal “agglomeration”, CBC reports.

The mayor said she had also “invited” city fund managers to divest, but “acknowledged the gesture was symbolic, given that her administration doesn’t have control over the funds.”

Romain Bédard, a spokesperson for the Ensemble Montréal opposition, said the measures didn’t go far enough. “Bédard said his party tabled a motion last fall proposing the city immediately block oil-burning heating in all new construction, and by 2028 for all buildings,” the national broadcaster notes. He called the pensions announcement a publicity stunt, since the mayor has “absolutely no control over what she is announcing.”

Less than a week later, Plateau-Mont-Royal Mayor Luc Ferrandez, who once served as interim leader of Plante’s Projet Montréal party, announced he was stepping down, believing he can achieve more against the climate crisis from outside the city administration.

“We had many occasions where I found out that I was much more radical than she was,” he told CBC Montreal’s Daybreak morning show, referring to Plante, who became mayor in an upset victory in 2017. “She is a balanced person, and she is thinking in terms of balance, but not me. I am thinking in terms of crisis. We should not be balanced anymore.”

Declaring himself a “very poor politician,” Ferrandez said his party had done more on the environment file than the previous administration, but not enough. “Ferrandez said he has been pushing for stronger measures, including buying up green space in the city and turning all non-residential parking spots into paid spots,” CBC states. But “according to Radio-Canada sources, the parking plan was a subject of concern for members of Plante’s executive committee, who felt that his desire to eliminate free parking spots downtown would spark a public backlash.”

For his part, “Ferrandez said he felt his own reputation was being used to boost the party’s reputation on the environment.”

Plante responded to Ferrandez’ announcement by saying she respected his commitment on climate. “There is a climate crisis, and we need to act—but what needs to be understood is that there is the City of Montreal, but we can’t act alone,” she said, adding the municipality must work with federal and provincial governments on transit and green initiatives.

“For me, I really have the impression that we’re doing our part,” Plante said. In his resignation letter, Ferrandez called for a series of “war measures” against climate change, including a tax on meat, lobbying against an airport expansion, and planting a half-million trees.

Last week, Montreal’s director of public health, Mylène Drouin, reported the city can expect climate change to bring more frequent, brutal heat waves like the one that killed 70 people in southern Quebec last summer. With 6.4 heat deaths per million population per day last year, “better public awareness and improved institutional responsiveness meant there were far fewer deaths than the summer of 2010, when there were 9.3,” CBC reports, but many of the 2018 deaths were still avoidable.

“The report found that low income and social isolation were key factors in the deaths attributable to that heat wave. Of those who died, two out of three were 65 years old or older, and nearly three in four—72%—had a chronic condition,” CBC states. As well, “a disproportionate number of deaths in 2018 occurred among people suffering from schizophrenia. Those victims made up 25% of the total, even though they represent just 0.6% of Montreal’s population.” Drouin explained that people with schizophrenia can be less sensitive to heat, and their medications can affect the body’s ability to cool off.