What does the cryptic crossword clue "Climate's upset a climber? (8)" mean?

The definition is "climber?". The wordplay uses an anagram. anagram of CLIMATE'S = CLEMATIS; definition: "climber?" The answer is CLEMATIS.

Climate's upset a climber? (8)

Daily Mail Cryptic #17098 | 16 Down | 2023-05-16 flower