Steven Guilbeault’s name has long been synonymous with environmental activism in Canada, but on Thursday, November 27, 2025, he made headlines for a very different reason: resigning from the federal cabinet in open protest of a new pipeline agreement between Ottawa and Alberta. The move, rooted in principle and conviction, marks perhaps his most dramatic act of defiance since his days of scaling skyscrapers and facing arrest as a Greenpeace activist.
According to the National Post, Guilbeault’s resignation came after the federal government, now led by Prime Minister Mark Carney, struck a memorandum of understanding with Alberta Premier Danielle Smith to advance a new oil pipeline. For Guilbeault, who had built his political identity on championing environmental causes, this was a step too far. In his resignation statement, he wrote, “I chose to enter politics to champion the fight against climate change and the protection of the environment… I remain one of those for whom environmental issues must remain front and centre. That’s why I strongly oppose the memorandum of understanding between the federal government and the government of Alberta.” He added that the decision caused him “great sadness.”
Guilbeault’s journey from radical activist to cabinet minister has never been straightforward. Born in Quebec to a butcher father and an Irish-Canadian mother, he learned English at home and was inspired by his uncle, a missionary in Haiti. His early activism began in high school, where he helped organize a student strike. He later studied political science and theology at the Université de Montréal, quickly gaining a reputation for his vocal environmental advocacy.
In 1997, Guilbeault joined Greenpeace, a move that would define his public persona for years to come. As a spokesman and campaigner, he became known for daring protest stunts. Perhaps the most famous of these came in 2001, when he and a colleague scaled 340 metres up Toronto’s CN Tower—Canada’s tallest landmark—before unfurling a banner reading “Canada and Bush Climate Killers.” The message, aimed at both the Canadian government and then-U.S. President George W. Bush, called for ratification of the Kyoto Protocol, an international treaty to reduce greenhouse gas emissions. The pair spent 12 hours on the tower before being arrested, an event that was widely covered by news crews and left a lasting impression on the Canadian public.
That arrest was hardly an isolated incident. Guilbeault was detained four times in total during his Greenpeace days, including for blocking a ship from unloading coal, fastening himself to oil equipment (which required the RCMP to use cherry pickers for removal), and installing solar panels on the roof of then-Alberta Premier Ralph Klein’s house in 2002. These high-profile stunts earned him both admiration and scorn. As the National Post notes, public opinion on Guilbeault has long been divided, with some viewing him as a bold champion for the environment and others as a reckless radical.
Despite—or perhaps because of—this notoriety, Guilbeault’s transition to politics was met with skepticism. In 2019, he ran as a star Liberal candidate in the Montreal riding of Laurier–Sainte-Marie, a seat he won from the NDP. He decorated his campaign office with a photo from his CN Tower protest, a nod to his activist roots. When asked about the new wave of environmental activists shutting down bridges in Montreal, Guilbeault remarked, “I decided I’ve already done that. As the anglophones say, ‘Been there, done that, got the T-shirt.’ I’ve decided to pursue my political action differently.”
Yet for some of his former activist colleagues, Guilbeault’s entry into federal politics was seen as a betrayal. The pipeline debate was already a hot button issue, and his willingness to work within the Liberal government drew criticism. “In many ways, I’m still this guy who climbed the CN Tower,” he told the National Post at the time, describing himself as a “radical pragmatist.”
Upon his election, Guilbeault was quickly appointed to Justin Trudeau’s cabinet, first as minister of Canadian Heritage and, after the 2021 election, as minister of environment and climate change. In that role, he launched the Emission Reduction Plan in 2022, which he described as a “roadmap” for Canada to meet its international commitments to cut carbon emissions by 2030. He also supported Trudeau’s carbon tax, a policy that was both lauded and fiercely opposed across the political spectrum.
Not all of Guilbeault’s decisions as environment minister were met with approval from environmentalists. He gave the green light to an east coast deep-sea oil drilling project—something he admitted was “particularly challenging” for him. The tension between his activist past and his governmental responsibilities was palpable. Conservative politicians seized on this, with Pierre Poilievre (then a backbench MP) dubbing him the “looney-left environment minister,” while Michelle Rempel Garner called him “an ideological anti-energy activist.”
These criticisms didn’t seem to faze him. Guilbeault’s personal history, shaped by activism and principled stands, had taught him to weather controversy. But the cabinet shuffle under Prime Minister Carney complicated matters. Guilbeault was moved from his environment post to a newly minted ministry of Canadian culture and identity, with added oversight of nature and Parks Canada. While some saw this as a nod to his environmental background, others interpreted it as a sidelining.
The final straw came with the federal government’s new agreement with Alberta, which included the controversial pipeline project. For Guilbeault, the deal represented a compromise he could not accept. In his resignation statement, he highlighted his decade-long record in government, but made clear that his core values remained unchanged. He vowed to stay on as a Liberal MP, signaling that his fight for environmental causes would continue—albeit from the backbenches.
Guilbeault’s story is, in many ways, a microcosm of the broader struggle within Canadian politics over climate change, resource development, and the limits of compromise. His career has been shaped by a willingness to take risks—whether dangling from a skyscraper or defying party leadership. For supporters, his resignation is a reaffirmation of principle over power. For critics, it’s a sign of the persistent tensions that dog environmental policy in a resource-rich country.
As the dust settles, one thing is clear: Steven Guilbeault remains, at heart, the same man who once scaled the CN Tower to demand action. His latest act of protest, this time from within the corridors of power, will likely fuel debate for years to come about the role of conviction in public life and the future of environmental politics in Canada.
