Verifying every claim you read on the internet is an impossible endeavor. It's much healthier for discourse if strong claims that aren't "general knowledge" for lack of a better term are ignored unless supplied alongside reliable sources or some sort of justification/explanation (and even then, making ridiculous claims and backing them up with heavily biased sources is a common tactic too).

This is mostly necessary in politically charged topics (energy generation (because that relates to climate change) and mentioning Russia specifically were both red flags to me) because spurious emotive bullshit and deliberate misinformation are very common.

This particular comment also didn't have enough information to be very useful - How much energy does the UK import from Russia? In what form? Has that amount changed recently? Why do you believe this is a bad thing? are all interesting questions the commenter could answer that would add to the conversation in a useful way.