Quote Originally Posted by belka
Quote Originally Posted by mashamania

The phrase "what is" is equivalent to "that which is" in this sentence. There's a small distinction between "The exact boundaries of what is climate" and "The exact boundaries of what climate is." It's not a mistake.

"What is" before a noun doesn't always imply a question, i.e. "He spoke of what is happiness." There's a minor distinction btwn "He spoke of what is happiness" and "He spoke of what happiness is." The former, happiness is the predicate and new information. The latter, the description of what constitutes happiness is the predicate or attribute.
Yes, I think mashamania has got it exactly right. Though it might help learners of English to know that the first version ("He spoke of what is happiness") is in my opinion much much less common than the second version. I'd be very surprised to find it anywhere other than in high-level philosophical, discursive or literary texts.

Белка.
Yes, I also think mashamania gave a good explanation.

And Белка is correct... normally this "style of grammar" is only used in textbooks for school, University and high-level texts. It's not a colloquial style... it's academic. And it is intended to "trigger" thinking in the reader or student.

No worries... Most native English-speakers wouldn't recognize the difference.

P.S. I like Dogboy's 'Jeopardy' analogy.