it's spitting on a fish, in terms of what's worse. climate scientists talk about tipping points and feedback cycles. whether hillary gets us there later or trump gets us there sooner isn't a logical separation point. what you're really doing is buying into hillary's argument of incrementalism on a topic that is really purely binary. that argument can work on social issues, wherr a little better is really a little better. but, whether you freeze to death at -40 or freeze to death at -50 is irrelevant - you still freeze to death. so, you can't really say she's bad but a little better on this issue. it's just not how climate science works. if the permafrost starts going, it starts going - and you can't fix it with small regulations. you have to go all in, or not at all. if anything, it's more rational to take trump's position, if we're fucked and can't stop it, anyways - which is not an obscure position, either.
but, nationalization is not purely a left-wing idea. it's also an idea that the far right has historically drawn heavily upon. the united states doesn't have a history of traditional conservatism like the other british states or the germans do, so it might seem a little foreign. but, british conservatives like churchill were strong advocates of state-run industry. so was bismarck. today, that's about where putin stands on the spectrum. hitler didn't support nationalization, but he rejected free markets; the nazi system was defined by cartels with monopolies. and, this was kind of the same as the colonial system in britain, where you had these private charters (like the hudson's bay company, or the east india company) that were essentially run by the crown. here in ontario, we used to have a publicly run electricity company that was set up by our old-tory conservative party.
there's actually even support for publicly run utilities in classical liberal literature (adam smith, for example) as well, but it justifies itself in more proto-leftist language. the argument from the right is very old and very classist. well, look at saudi arabia. there's no private industry. it's all run by the state. communist? hardly. it's about concentration of wealth in the upper crust. state ownership is seen as a kind of firewall to keep the wealth in the hands of the aristocratic elite.
the more relevant question is probably related to whether trump has thought this through carefully or not. britain (and canada) have been democracies for a long time. germany wasn't. but even in britain (and canada) you have this system with the house of lords and these private charters that is just designed along this strenuous class lines. i'm not sure how one would propose this be emulated in the united states, or whether an elected senate (however weak it is...) may actually make that functionally impossible. but, most of what he says is functionally impossible, so that should be no surprise.
it's just not necessary to see this as a left-wing idea. and, if you want to look at ways that this could be done today, russia is probably your closest comparison. that might even be a broad statement: putin may be the best predictor of what trump would actually be like.
https://www.youtube.com/watch?v=9hvxmMIbaAM
also - the canada thing is complicated. the numbers may have changed in the last few years, but we are usually actually thought of as a net importer, despite being able to potentially be independent. but, it's because the costs of production are so high that it's cheaper to import it. we tried to set up something called the "national energy program" in the 70s through a state run company (it wasn't a monopoly, just a crown corporation) that would have made us energy-independent through a complex system of subsidies, but the province of alberta flipped out. and, it was, in fact, a reaction to the opec embargo and the stagflation that resulted from it. it even worked. but, the consequence was that the bubble economy in alberta collapsed. housing prices fell, for example; it was, in truth, a correction on a bubble, but try explaining that to the guy that has his house fall by 80%. so, we could actually do this, and have tried, and may try again, but it's politically very difficult in the oil-producing regions.