“Facts” are a human concept. Prove otherwise.
Depends on your definition or concept. Is this an attempt by a conservative to nudge us toward Trump?
Asking to prove an opinion on a definition is just silly!
If we agree that the color we see as lettuce is called green and adopt that convention, it could be said that it is a fact that lettuce is green, aside from red varieties, but if you choose to call green red and yell alternative facts or fake news, I don't have time for you.
A fact is a truth. A fact exists whether or not humans see/contemplate it. A "fact" is a simple noun which represents a truth. "Concept" might have very different meanings, depending on whose mind is shaping it.
"Concepts" are a human concept... unless aliens have concepts, too.
And speaking of aliens, I would expect that, as a mark of intelligence, facts—like mathematics—would be discovered independent from us.
But who knows? For now, we only know that facts are localized to human minds.