I am talking about raw scientific possibility, and a good rule of thumb is: if you see it in nature, then it is assuredly possible, and humans will eventually do it a thousand times better.
Cold fusion: Does not exist in nature. Only exists in (controversial) theory. I'll believe it when I see it.
Hot fusion: Exists in nature so it's possible. After developing the technology, humans will be able to do it better. Will take a while.
Flight: Exists in nature, so it's possible. After developing the technology, humans can do it better. Took a while.
Intelligence: Exists in nature (ie you and me). After developing the technology, humans will be able to do it better. Will take a while.
See the pattern?