Canada’s ruling Liberals sweep special elections in boost to Mark Carney | Canada
(www.theguardian.com)
Just like Carney, you have reasonable limits on your commitments. You would likely be broke and unhappy if you tried to be a purely ethical person. Similarly, Canada also has realistic constraints.
You might also actually read the article to which you linked? Unless you feel that no government can update another's goals, it's a pretty silly lawsuit. (Imagine Harper had passed legislation saying that government policy could never again consider carbon emissions, would all future governments be bound by that too? If not, what's the difference other than you liking one and not the other?)