"[2] Breton subsequently founded Québec-Vert-Kyoto (later known as QuébecKyoto), which advocated in favour of the Kyoto Accord on climate change.

In 2004, he led an ultimately successful protest against Hydro-Quebec's plans to launch the Suroit natural gas power project near Beauharnois.

[4] In June 2007, Breton called on Canadian environment minister John Baird to resign over the Stephen Harper government's handling of the Kyoto Accord.

[6] On November 29, 2012, Daniel Breton resigned from his post as environment minister less than two months after taking office.

He was the minister of Sustainable Development, Environment, Wildlife and Parks from September 19 to November 29, 2012[11] in the government of Pauline Marois.