Based on my experience of Canadian environment ministers (whatever the department is called at a given time), there are essentially two types. The rarer type is the genuine environmentalist who thinks they can get things done through the compromises of government. They’re true believers on climate change but rarely have much support from cabinet or the prime minister because what they want to do is not actually popular. Set in the abstract, people want to keep the climate stable and protect the planet. Give them the choice between that and something concrete, however, and you have the recipe for delay and misdirection which has been ongoing in Canada for 30+ years. I would say Stéphane Dion and Catherine McKenna are the clearest example of the genuine environmentalist set, and demonstrate how people with those priorities get sidelined. When you have no natural allies in cabinet because most of the other departments are pro-fossil (industry, transport, finance, natural resources, etc) the constraints of cabinet solidarity put ministers of this type in the position of unsuccessfully demanding the bare minimum behind closed doors, before defending inadequate plans to the public.
The other type of Canadian environment minister is the public relations spinmaster whose behaviour does not demonstrate any sincere concern about climate change, but simply the need to manage it as a PR issue. This is a much easier approach to the job since you can always just say nice things, avoid hard decisions, and cut dirty deals in the background. I feel like John Baird, Jim Prentice, Peter Kent, and Jonathan Wilkinson fall in this category. My father recently collected a set of letters on climate change for Minister Wilkinson (mine is here) and the experience illustrates how Wilkinson is a PR man for a government which in practice largely serves the same interests as the Harper Conservatives, but who work to maintain a false public and media narrative that they are bold environmental champions.
Part of the problem, surely, is that politicians have a hopelessly distorted understanding of the scale against which they should be judged. They give themselves kudos for being better than some of their electoral competitors, rather than comparing the scale of the efforts they propose against the scale of what needs to be done. The consequences are that the future becomes more dire for everyone, and that Canada will have an infrastructure and economic base poorly matched to what success in a post-fossil world will require.