My karma in Code Review was two days ago around 16400+. Now it is 22700+. What happened here? I received my 8th golden badge; might it be responsible for that? Also, there is no any indication from which answers or questions those points came.
Upvotes on questions used to be worth 5 reputation points (what you call karma). They recently (Wednesday 13th of November) increased this to 10 points, doubling the amount of reputation you get for a question upvote. Retroactively, so it counts for every upvote you ever got on a question (taking into account things like reputation caps per day (200) and all, it won't be double but at least a heck of a lot higher).
You have asked 354 questions on Code Review. I'm not going to do the math for you, but yes, I'd expect you to gain a couple of thousand rep from this move.
Blog post by SE which attempts to explain it:
Relevant Meta.StackExchange questions if you're looking for extra information: